Stone Domes in the Pine Valley Mountains, Utah

[dtyler]

Driving through Highway 18 in southwestern Utah, the visitor sees forested terrain with few rock outcrops and may be tempted to think that Hutton’s cycle of uplift and erosion is just as applicable here as anywhere else.

However, detailed mapping of the area has revealed a remarkable story involving the rapid intrusion of laccoliths, with associated arching of overlying rocks, massive gravity sliding, and synchronous volcanic eruptions” (Willis, 2002). The dramatic nature of these past events, and the speed of formation of geological structures, should make us stop and think about our basic approach to geological interpretation.

The events took place in the Tertiary. Thick layers of Jurassic and Cretaceous rocks had been laid down, and covered by Eocene strata. Then came the igneous intrusion: the magma was a viscous combination of quartz monzonite and granodiorite. It moved up from deep within the Earth’s crust, but instead of breaking out at the surface, it found layers of weakness in the surface strata and moved laterally. It ponded and formed a dome-shaped structure called a laccolith. This uplifted the surface rocks and this is where the story really gets interesting.

A chain-reaction series of events followed the intrusions. “First, the doming magma fractured and oversteepened the overlying layered rocks. The elevated weakened layers then broke loose and slid down the flanks of the domes as massive gravity slides. The sudden removal of the slide masses produced an immediate large reduction in confining pressure. This then caused still-intruding magma to burst through the seal and erupt, first ejecting vapor-rich (high-volatile) tuffs, then vapor-poor lava flows, which draped across the new gravity slide masses.” (Willis, 2002) The whole cycle repeated itself several times, with new laccoliths being formed and then bursting their sediment seals.

Timescales for these events were comparatively short. “Ages and relationships of the outcrops throughout the area strongly indicate that each laccolith intruded and domed within just a few years, or less. The gravity slides probably occurred even faster. Most likely, they were catastrophic events that, once started, happened within minutes, similar to the massive landslide on Mount St. Helens in May 1980 that triggered the disastrous eruption that took 60 lives. It would have been an incredible sight to watch huge slabs of rock several hundred feet thick rush down a mountain slope and run out across the landscape several miles!” (Willis, 2002).

Some of these slides were huge: the largest is more than 60 square miles in area, 1800 feet thick and it traveled over 12 miles. When they moved, the laccolith was unroofed and pressure release led to the eruption of volcanic ash and some lava flows. The remains of all this activity has been identified in careful mapping work.

Some general thoughts follow.

1. Geologic processes in the past do not necessarily fit our preconceived ideas about rates of process or even types of process. Be prepared for some surprises when you investigate the Earth’s history. Some processes were very short – measured in hours, days or years.

2. Igneous processes tend to be stretched out over thousands or even millions of years, but this expectation needs to be revised. Whether we are considering magma segregation, magma transport to the surface, emplacement or cooling: all these processes can take place much faster than previous generations of geologists surmised.

3. In most cases, geological research has explored timescales in only a limited way – because “everybody knows” that the timescales are in millennia or longer. More rigorous work, that looks for clues about timescales, invariably finds that past estimates have been too long. A case in point was posted by Glenn Morton at http://www.theologyweb.com/forum/showthread.php?t=20334. The Great Stone Dome is known from seismics and boreholes, but is not accessible to field geologists. In such a case, a variety of scenarios could be proposed to explain the data – but testing these scenarios would be quite difficult. It is more useful to argue from geological structures where we do have the opportunities to test hypotheses more effectively.

4. A Flood Geology Understanding of the Pine Valley Mountains. Those who have followed previous threads to which I have contributed will know of my interest in developing and testing the Recolonisation model of earth history. This involves a global catastrophe (linked to the biblical history of Noah’s Flood) followed by an extended period of more local catastrophism as the Earth recovered from the destruction of the pre-Flood world. These particular events would then be part of the post-Flood catastrophism affecting the North American continent. The timescales indicated in my notes above are fully consistent with this scenario.

Reference
UTAH GEOLOGICAL SURVEY NOTES, September 2002, 34(3), 1-3.
http://geology.utah.gov/surveynotes/snt34-3.pdf

[SteveF]

So basically, some things happen fast. Thats fine, we know they do. They leave signatures in the rock record that show they happened quickly. On the other hand there are many processes that have led to the geology we see today that can not reasonably have happened quickly.

Just showing some examples of rapid events hardly strengthens your case. Furthermore, as the above example appears to show, geologists do not rule out rapid occurences. There is hardly a need for a complete rethink to incorporate catastrophism when it is incorporated into modern thinking anyway. Uniformitarianism vs catastrophism is old hat.

[Monkey Boy]

1. Geologic processes in the past do not necessarily fit our preconceived ideas about rates of process or even types of process. Be prepared for some surprises when you investigate the Earth’s history. Some processes were very short – measured in hours, days or years.

Why should this be surprising to anyone? We've all seen volcanic eruptions, landslides, and floods.

2. Igneous processes tend to be stretched out over thousands or even millions of years, but this expectation needs to be revised. Whether we are considering magma segregation, magma transport to the surface, emplacement or cooling: all these processes can take place much faster than previous generations of geologists surmised.

Geologists aren't stupid you know. There are ways to get a rough measure of the timescale of an event. As just one example, the speed of cooling of an igneous formation can be roughly gauged by looking at the size of the crystals in the rock. The larger the crystals, the slower the cooling.

3. In most cases, geological research has explored timescales in only a limited way – because “everybody knows” that the timescales are in millennia or longer.

Yes, David, this issue was settled 150 years ago. Just because you are in denial doesn't mean everyone else shouldn't move on to more productive questions.

More rigorous work, that looks for clues about timescales, invariably finds that past estimates have been too long.

I think "invariably" may be a bit of a hyperbole, don't you? The Grand Canyon has surely been the object of rigorous work, yet I don't hear of it getting any younger.

The timescales indicated in my notes above are fully consistent with this scenario.

Tell us again, David, how long ago did the article say these events happened? How in the world is that consistent with your young-earth scenario?

And need I remind you yet again that your whole model presumes a world-wide catastrophe for which you have provided zero physical evidence.

[Kulindrichnus]

Be prepared for some surprises when you investigate the Earth’s history

like the biodiversity of filey brigg, for instance. Seemed a surprise to you.

K

[dtyler]

So basically, some things happen fast. Thats fine, we know they do. They leave signatures in the rock record that show they happened quickly. On the other hand there are many processes that have led to the geology we see today that can not reasonably have happened quickly.
What we are not so good at is discerning the signatures - largely because we come to the data with expectations.

Just showing some examples of rapid events hardly strengthens your case. Furthermore, as the above example appears to show, geologists do not rule out rapid occurences. There is hardly a need for a complete rethink to incorporate catastrophism when it is incorporated into modern thinking anyway. Uniformitarianism vs catastrophism is old hat.
Maybe it is old hat. But some are still wearing the old hat of uniformitarianism!
I did not post this thread just to give yet another example of catastrophism. Diluvialists are being charged with ignoring evidence about slow processes - yet the evidences presented are only effective against people who say the geologic column (or most of it) was laid down in 1 year. This also is old hat and I would like to see us move the discussion into more productive areas. This post can be interpreted as a protest against the methodology of Glenn Morton, bringing us a Stone Dome that can only be examined by seismics and drill cores. I seek a higher standard of debate - further comments are in post 1.

[SteveF]

What we are not so good at is discerning the signatures - largely because we come to the data with expectations.
I think we are doing a pretty good job. I'm training in Quaternary sciences and can cite numerous examples (Younger Dryas stadial for example) where we have been able to see events in the past that have occured quickly.

You still can't get away from the fact that there are events and processes that can not reasonably have been expected to have occured in a short space of time.

Do you not think that your expectations (largely without foundation) are causing you to be a little biased?

Maybe it is old hat. But some are still wearing the old hat of uniformitarianism!
Geologists fully accept that things have happened quickly in the past. I think you are behind the times.

I did not post this thread just to give yet another example of catastrophism. Diluvialists are being charged with ignoring evidence about slow processes - yet the evidences presented are only effective against people who say the geologic column (or most of it) was laid down in 1 year. This also is old hat and I would like to see us move the discussion into more productive areas.
One year or a couple of thousand. It makes very little difference, its still not enough time. Nothing you have posted so far suggests otherwise, no positive evidence whatsoever.

You have posted here an example of geologists who fully accept that something happen quickly which rather diminishes your point about a debate being needed over timescale. Furthermore, just finding a couple of places where something happens relatively fast is not convincing support for your model.

Geology fully accepts variable timescales and fits them into a framework that is doing a pretty good job of explaining the data we collect. Things that occur slowly and a number of things that occur quickly explains things. Hypothesising that pretty much everything happens quickly explains nothing in a remotely coherent fashion.

This post can be interpreted as a protest against the methodology of Glenn Morton, bringing us a Stone Dome that can only be examined by seismics and drill cores.
I am sure Glenn doesn't feel that seismics and drill cores are the only methodologies available to us. What he has done is provided seismic data and drill core data that is nigh on impossible to fit into a YEC framework be it your or a one year version.

I seek a higher standard of debate - further comments are in post 1.
I am genuinely not being facetious when I ask why haven't you attempted to get this debate going in the peer reviewed literature. Submit something to sedimentary geology for example.

Through all this talk of seeking improved debate you have not yet once provided any vaguely convincing evidence for your model. Is fostering debate all you seek to do?

[dtyler]

Why should this be surprising to anyone? We've all seen volcanic eruptions, landslides, and floods.
Nothing like on this scale.

Geologists aren't stupid you know. There are ways to get a rough measure of the timescale of an event. As just one example, the speed of cooling of an igneous formation can be roughly gauged by looking at the size of the crystals in the rock. The larger the crystals, the slower the cooling.
You are right: geologists are not stupid. It is no reflection on the integrity of geologists to say that they also bring presuppositions to the data that affect their interpretation of it. My concern is with those who can't or won't agree with this comment. The example of magma cooling and crystallisation is a good one. For years, this was used as an argument for vast ages for granite crystalisation. Then laboratory studies started to show that the ages might not be so long. A recent study says that the time scale can be "years as opposed to millenia".

Granite recrystallization: The key to the nuclear waste problem?, Fergus G.F. Gibb and Philip G. Attrill, Geology: Vol. 31, No. 8, pp. 657–660.
ABSTRACT: We report the outcome of high-temperature, high-pressure experiments showing that granite can be partially melted and completely recrystallized on a time scale of years as opposed to millennia as widely believed. ...

Geologists are not stupid - but all the more reason to keep questioning things that can be traced back to the influence of Lyell.

I think "invariably" may be a bit of a hyperbole, don't you? The Grand Canyon has surely been the object of rigorous work, yet I don't hear of it getting any younger.

That's not what I hear:

Catastrophic floods built Grand Canyon
GRAND CANYON NATIONAL PARK, Ariz., July 20, 2002, Saturday

Dams of volcanic rock laid across the Grand Canyon have burst repeatedly and catastrophically over the past million years -- most recently about 165,000 years ago -- carrying enormous onrushing floods and carving out much of the great landmark in the blink of a geologic eye, new research by U.S. Geological Survey and University of Utah geologists suggests.

The findings tend to support other new data indicating the canyon's Inner Gorge may be no more than 700,000 years old, much younger than earlier estimates of 3 million to 5 million years, said Robert Webb, a research geologist with USGS. ...

[Jimmy Higgins]

I don't understand the point here. Geologists aren't glued to the "its all long" thought process. Geologists are pretty sure that the Whirlpool bend of Niagara Gorge was formed in days. Does that mean Niagara Falls progressed to its current condition in weeks? Of course not.

[dtyler]

I think we are doing a pretty good job. I'm training in Quaternary sciences and can cite numerous examples (Younger Dryas stadial for example) where we have been able to see events in the past that have occured quickly.

You still can't get away from the fact that there are events and processes that can not reasonably have been expected to have occured in a short space of time.
of course I welcome the signs of greater realism in geological science. I'm encouraged by your comments re the Quaternary. Of the examples presented to us on TheologyWeb, I have engaged with the ones I've thought were more significant. I continue to think that the discussion is misdirected - Glenn has himself said that I represent minority within Diluvialism and his guns are primarily for the majority view. That excludes me from a lot of detailed discussion - but it also fails to address the real issues.

Do you not think that your expectations (largely without foundation) are causing you to be a little biased?
If you omitted the words in parenthesis, I will acknowledge that I have a bias. But I am aware of it and seek to guard against jumping to conclusions.

Geologists fully accept that things have happened quickly in the past. I think you are behind the times.
If that were my point, I would be.

re Glenn doesn't feel that seismics and drill cores are the only methodologies available to us. What he has done is provided seismic data and drill core data that is nigh on impossible to fit into a YEC framework be it your or a one year version.
I do not think this example has enough data to allow a conclusion to be drawn.

[SteveF]

Nothing like on this scale.


You are right: geologists are not stupid. It is no reflection on the integrity of geologists to say that they also bring presuppositions to the data that affect their interpretation of it. My concern is with those who can't or won't agree with this comment. The example of magma cooling and crystallisation is a good one. For years, this was used as an argument for vast ages for granite crystalisation. Then laboratory studies started to show that the ages might not be so long. A recent study says that the time scale can be "years as opposed to millenia".

Granite recrystallization: The key to the nuclear waste problem?, Fergus G.F. Gibb and Philip G. Attrill, Geology: Vol. 31, No. 8, pp. 657–660.
ABSTRACT: We report the outcome of high-temperature, high-pressure experiments showing that granite can be partially melted and completely recrystallized on a time scale of years as opposed to millennia as widely believed. ...

Geologists are not stupid - but all the more reason to keep questioning things that can be traced back to the influence of Lyell.



That's not what I hear:

Catastrophic floods built Grand Canyon
GRAND CANYON NATIONAL PARK, Ariz., July 20, 2002, Saturday

Dams of volcanic rock laid across the Grand Canyon have burst repeatedly and catastrophically over the past million years -- most recently about 165,000 years ago -- carrying enormous onrushing floods and carving out much of the great landmark in the blink of a geologic eye, new research by U.S. Geological Survey and University of Utah geologists suggests.

The findings tend to support other new data indicating the canyon's Inner Gorge may be no more than 700,000 years old, much younger than earlier estimates of 3 million to 5 million years, said Robert Webb, a research geologist with USGS. ...
Still no positive evidence David. All it shows is the scientific method in action (assuming these new findings become accepted) and the fact that geologists aren't constrained by uniformitarianism!

[SteveF]

of course I welcome the signs of greater realism in geological science.
They aren't just signs though. They are fully accepted and have been for a while. Some things still happen slowly though.

If you omitted the words in parenthesis, I will acknowledge that I have a bias. But I am aware of it and seek to guard against jumping to conclusions.
But your expectations are largely without foundation. There aint no evidence (scientific anyway) for them. if you are aware of it, then how come you are still reaching conclusions unsupported by the data?

If that were my point, I would be.
It strikes me that one of your points is that geologists don't accept that some things can happen quickly. They do. As I said, they have a perfectly coherent framework that explains the data well.

I do not think this example has enough data to allow a conclusion to be drawn.
Glenn has provided many examples (and will no doubt provide anymore) that have gone unadressed.

I'm happy to continue this with you David but I'm off home now and probably won't check TWeb till Sunday/Monday.

[Monkey Boy]

Nothing like on this scale.

You're begging the question. The eruption of one individual dome would have been no more catastrophic than St. Helens, Pompeii, or Kratatoa. You can't assume that all of the domes erupted simultaneously. Even if they did, so what? Again we all know that really big catastrophes are (thankfully) more rare than run-of-the-mill catastrophes.

You are right: geologists are not stupid. It is no reflection on the integrity of geologists to say that they also bring presuppositions to the data that affect their interpretation of it. My concern is with those who can't or won't agree with this comment. The example of magma cooling and crystallisation is a good one. For years, this was used as an argument for vast ages for granite crystalisation. Then laboratory studies started to show that the ages might not be so long. A recent study says that the time scale can be "years as opposed to millenia".

Granite recrystallization: The key to the nuclear waste problem?, Fergus G.F. Gibb and Philip G. Attrill, Geology: Vol. 31, No. 8, pp. 657–660.
ABSTRACT: We report the outcome of high-temperature, high-pressure experiments showing that granite can be partially melted and completely recrystallized on a time scale of years as opposed to millennia as widely believed. ...

You're quote mining David, and that's dishonest. Here's a longer excerpt from the paper:

Among the potentially more robust of the scenarios proposed for disposal of small to moderate volumes of HLW in deep boreholes is the "high-temperature, very deep disposal" scheme of Gibb (1999, 2000). In this, special cylindrical containers filled with heat-generating HLW are deployed in the lower part of a 4-5 km deep borehole in granitic continental crust. Heat from the waste fairly rapidly generates a substantial zone of partial melting in the granite surrounding the containers. As the heat output decreases this melt will cool slowly and recrystallize to seal the waste packages into a sarcophagus of solid crystalline granite surrounded by zones of metamorphosed and annealed rock. For this to work two things are crucial. First, sufficient melting of the granite must occur at temperatures low enough to preserve the integrity of the containers and second, this partial melt must be able to recrystallize completely to a holocrystalline rock. Both have to happen on time scales appropriate to the thermal decay of the waste. For the case of 5 year old spent PWR fuel modelled by Gibb (2000) it would take around 65 days for the rock adjacent to the container to reach a maximum temperature of 850 °C and 2.5 years to fall to 600 °C. The latter is equivalent to a cooling rate of ~0.011 °C/hour.

Cooling rates deduced from natural granite bodies have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years but there are grounds for believing that acid (silica-rich) magmas can be completely crystallized at cooling rates orders of magnitude faster. To test this, and hence the feasibility of the high-temperature borehole disposal scheme described above, partial melting and recrystallization experiments were performed on a typical S-type granite, with a range of H2O contents, under the conditions predicted to occur in the disposal scheme.

From http://www.shef.ac.uk/isl/abstracts/abs2003.html#anchor23

Geologists are not stupid - but all the more reason to keep questioning things that can be traced back to the influence of Lyell.

Why? Even the creationst geologists of the time were ultimately convinced.

That's not what I hear:

Catastrophic floods built Grand Canyon
GRAND CANYON NATIONAL PARK, Ariz., July 20, 2002, Saturday

Dams of volcanic rock laid across the Grand Canyon have burst repeatedly and catastrophically over the past million years -- most recently about 165,000 years ago -- carrying enormous onrushing floods and carving out much of the great landmark in the blink of a geologic eye, new research by U.S. Geological Survey and University of Utah geologists suggests.

The findings tend to support other new data indicating the canyon's Inner Gorge may be no more than 700,000 years old, much younger than earlier estimates of 3 million to 5 million years, said Robert Webb, a research geologist with USGS. ...

I was not clear on my prior comment. In my mind, the origin of the GC begins with the deposition of those very first sedimenary layers. It's not the sculpting of the canyon per se that belies its age, it's the geological history written in its rocks.

[aniso]

1. Geologic processes in the past do not necessarily fit our preconceived ideas about rates of process or even types of process. Be prepared for some surprises when you investigate the Earth’s history. Some processes were very short – measured in hours, days or years.

Yes, David, we know this. When did you discover that there are some rapid geological processes? Many of them, in fact. It still astounds me that you continue to entertain this illusion that, somehow, YECs are the ones who discovered rapid geological processes.

2. Igneous processes tend to be stretched out over thousands or even millions of years, but this expectation needs to be revised.

If ALL geological processes were rapid, on a human scale, this is true. However, you have been unable to support this presupposition of yours.

And actually the 'expectation' is revised when the evidence warrants it. Just as your reference shows. It would seem to me that science is working just the way it is supposed to. Perhaps your paradigm of paradigm change needs drastic revision, eh?

So, what is your problem? You need to go out and collect the data. Not just an anecdote that fits in with mainstream geology, anyway. You need substantial evidence showing that an entire class of processes is rapid and further that all associated processes must be equally rapid. We know that many volcanic processes are rapid (or did you think that one escaped us?), so really, you have given us absolutely nothing here but an interesting mainstream geological theory. I experience no sense of shock at all, and have no concern that my world is about to be turned up-side down.

Whether we are considering magma segregation, magma transport to the surface, emplacement or cooling: all these processes can take place much faster than previous generations of geologists surmised.

Wrong. Many geologists were taught about kimberlite intrusions, caldera formation and the unroofing of core complexes etc. Once again, I am sorry that your education was incomplete.

3. In most cases, geological research has explored timescales in only a limited way – because “everybody knows” that the timescales are in millennia or longer. More rigorous work, that looks for clues about timescales, invariably finds that past estimates have been too long. A case in point was posted by Glenn Morton at http://www.theologyweb.com/forum/showthread.php?t=20334. The Great Stone Dome is known from seismics and boreholes, but is not accessible to field geologists. In such a case, a variety of scenarios could be proposed to explain the data – but testing these scenarios would be quite difficult. It is more useful to argue from geological structures where we do have the opportunities to test hypotheses more effectively.

And exactly what is your point here? The first part of the statement having been shown invalid, of course.

4. A Flood Geology Understanding of the Pine Valley Mountains. Those who have followed previous threads to which I have contributed will know of my interest in developing and testing the Recolonisation model of earth history. This involves a global catastrophe (linked to the biblical history of Noah’s Flood) followed by an extended period of more local catastrophism as the Earth recovered from the destruction of the pre-Flood world. These particular events would then be part of the post-Flood catastrophism affecting the North American continent. The timescales indicated in my notes above are fully consistent with this scenario.

So, these post-Eocene events happened outside of human memory even though by then the flood was over and the recolonization of the world was well underway? No, this doesn't fit at all. You've only got 4000 years to deal with, David. There should be excellent records of all of these catastrophes that you cram into 4000 years. After all, the flood itself is so well documented in the Bible.

In your next post, perhaps you could tell us how all these huge catastrophes could happen, but that overthrusts are imaginary as most YECs tell us.

[SedRocks]

[QUOTE=dtyler]The dramatic nature of these past events, and the speed of formation of geological structures, should make us stop and think about our basic approach to geological interpretation.[\QUOTE]

Dave Hacker's Ph.D. dissertation (the source of the findings you are citing) was a triumph of traditional geology, as it combined meticulous field mapping, ceaseless stomping over the countryside, careful attention to subtle clues in the rocks, and meticulous working out of the details regarding temporal sequence and spatial arrangement. The main thing that Dave Hacker's dissertation makes us stop and think about is how good classical geological methods are and how much can be learned from very classical field work.

Dave, you are right that from Lyell until Hurricanes Donna and Camille and Harlan Bretz' triumph regarding the Channeled Scabland floods geologists had an overall bias against sudden and in favor of gradual. Basically this was an over-reaction against (1) Cuvier's catastrophism and, (2), more generally, against biblical geology of various stripes, both of which have been continual utter failures when measured against all incoming evidence since about 1820, combined with being extremely impressed with Lyell's Principles of Geology to the extent of exaggerating its uniformitarian themes.

However, as Aniso said, geological classrooms are now full of information about inferred sudden kimberlite eruptions, rapid drainings of large lakes, rapid floodings of Black Seas and Mediterranean basins, sudden collapses of volcanoes, and so forth.

Dave, as I've said before on other threads you are fighting a view of geology that has had no basis in reality for the past 35 years. You have set up a strawman that does not exist.

As a demonstration of this, it is hard fact that none of the geologists involved with or overseeing Dave Hacker's Ph.D. research were astonished by his inferences regarding rapid progression from landsliding through ash eruption to generation of lava flows, although everyone was impressed by how well he marshalled his evidence. No one involved with the research thought the rapidity was unthinkable, or that it broke any sacred uniformitarian paradigms. No one walked out of his dissertation defense in protest, and none of us thought about becoming a flood geologist as a consequence of his findings.

Dave Hacker also showed that these laccoliths happened in succession rather than all at once, and he showed that they happened a long time ago, not recently. I've forgotten what you consider to be post-flood, but you still have a heck of a lot of complex post-laccolith geologic events to find time for, even just in southern Utah. I don't think any justification exists for your claims that these "particular events would then be part of the post-Flood catastrophism affecting the North American continent", or that "the timescales indicated in my notes above are fully consistent" with such a scenario.

[grmorton]

Maybe it is old hat. But some are still wearing the old hat of uniformitarianism!
I did not post this thread just to give yet another example of catastrophism. Diluvialists are being charged with ignoring evidence about slow processes - yet the evidences presented are only effective against people who say the geologic column (or most of it) was laid down in 1 year. This also is old hat and I would like to see us move the discussion into more productive areas. This post can be interpreted as a protest against the methodology of Glenn Morton, bringing us a Stone Dome that can only be examined by seismics and drill cores. I seek a higher standard of debate - further comments are in post 1.

But David, you haven't even attempted an explanation of the Great Stone Dome. Your silence on the topic can't be considered evidence in favor of your position. I showed that even if one accepts the ridiculous cooling rates of Woodmorappe and Snelling, it still takes longer than the YEC age of the earth for the geology of the East Coast of the US to be explained. And using that same ridiculous cooling rate, your 2000 years after the flood recolonization model doesn't fit either. So, the Great Stone Dome destroys your viewpoint.

By the way, David, since you believe that only the Cambrian and Ordovician strata are due to the flood, can you tell me what animals were doing walking around on Cambrian and Ordovician strata while the flood raged around them?

edited to add: David, frankly, I am ashamed for you about the quote mining you did. By selectivly quoting that bit about granite crystalization, you show yourself not to be a worthy opponent.

[aniso]

I was not clear on my prior comment. In my mind, the origin of the GC begins with the deposition of those very first sedimenary layers. It's not the sculpting of the canyon per se that belies its age, it's the geological history written in its rocks.

Keeping in mind here that the reference was only to the INNER canyon and not the entire canyon; and it also referenced a most recent even of 160 ky ago. Hardly supporting evidence for David and the young earth.

[Kulindrichnus]

Derek Ager (beloved of Creationists, but I doubt many of them ever heard him give his opinion of them) said some quarter of a century ago that the stratigraphical column represented 'long periods of boredom punctuated by brief periods of terror'.

Sedimentary geologists have known, long before Ager, that most sedimentation happens quickly. Any modern analogue or flume-tank studies will tell them this. Deep time is not locked up in preserved sedimentary deposits; it is locked up in the relationships between them- in the colonised bedding planes, the tiered bioturbation horizons, the intraformational erosion surfaces which mark the nonpreservation of sediment, the major unconformities, the diagenetic histories, the multiple histories of deformation, erosion, and redeformation.

David is simply comforting himself by shouting about the rapidity of deposition exhibited by sedimentary (including landslide or volcaniclastic units, as here) rocks, because, as he well knows, the deep time he seeks to discredit is not there. David's hidden suggestion in doing this is that if we look for deep time in these sediments and do not find it, then it must not exist. This may satisfy the fools or ignorants who wish to believe; but it is akin to saying that if I do not find concorde in my garage then it was never built. Such a position is not scientific, nor even honestly misled; it is deliberately disingenuous.

In comparison, David seldom engages meaningfully on those threads where deep time is inescapeable- for instance, Glen's recent threads on the diagenetic precipitation of anhydrite through sabkha dessication and the reworking of conglomerate, or Glen's dozens of posts about bioturbation- and when he does, he employs disingenuous tactics (such as the comparison of desert denudational geomorphologies with marine ones) easily dismissed by the real geologists he apes on this board.

By the way, David, I did my entire PhD on seismic and drill cores. Your suggestion that the conclusions drawn from such studies must be doubted because the nature of the study itself makes falsification of hypotheses difficult is both erroneous, deeply offensive, and shows, clearly, that you have never undertaken such a study yourself. The area you live in owes its (former) prosperity to 200 years of subsurface exploration, with very satisfactory results. I suspect you know this well enough, but that you cannot rein in your urge for duplicity. As Glen has said, once again you show yourself to be an unworthy opponent.

K

[dtyler]

But David, you haven't even attempted an explanation of the Great Stone Dome.

I'm just picking up this thread again after a time away. I have not attempted to explain the Great Stone Dome argument you gave us because I do not think I have much data to work with. Whatever *anyone* says is speculative - including your arguments for long timescales. I was thinking how to respond to this kind of argument and the response I came up with was to show you that at least one dome-shaped igneous body requires a catastrophist scenario to explain the data. If one requires short timescales, then why not others? This sends us back to the data - we need to gather the evidence that will allow us to draw a meaningful conclusion (and avoid presuming long timescales).

By the way, David, since you believe that only the Cambrian and Ordovician strata are due to the flood, can you tell me what animals were doing walking around on Cambrian and Ordovician strata while the flood raged around them?

This is not part of this thread - and animals were not walking around on Cambrian and Ordovician strata during the Flood.

edited to add: David, frankly, I am ashamed for you about the quote mining you did. By selectivly quoting that bit about granite crystalization, you show yourself not to be a worthy opponent.

So, it is selective quotation to quote the first sentence of the author's abstract! The rest of the abstract deals with the burial of radioactive waste, so I cut it. I have seen another part of the paper quoted, but it says the same thing! The point I was making is a perfectly fair one and I have no reason to think that my use of the paper is selective. Here is a sentence in the quote posted earlier: it is exactly the point I was making.
Cooling rates deduced from natural granite bodies have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years but there are grounds for believing that acid (silica-rich) magmas can be completely crystallized at cooling rates orders of magnitude faster.Why is it that when the authors of the paper write those words, they are deemed to be engaging in scholarly activity, whereas when I write something similar and quote these authors, I am accused of quote mining?

[Monkey Boy]

Why is it that when the authors of the paper write those words, they are deemed to be engaging in scholarly activity, whereas when I write something similar and quote these authors, I am accused of quote mining?

Because the context of the paper does not address the question of whether granites crystallize rapidly in a natural setting. It addresses the question of whether granite can crystallize completely when cooled rapidly under artificial conditions. The fragment you quoted excludes this important context and is used to support a position which the context does not warrant. Thus it constitutes quote mining on your part.

[dtyler]

Because the context of the paper does not address the question of whether granites crystallize rapidly in a natural setting. It addresses the question of whether granite can crystallize completely when cooled rapidly under artificial conditions. The fragment you quoted excludes this important context and is used to support a position which the context does not warrant. Thus it constitutes quote mining on your part.

The context was certainly not overlooked. It was explicit. This was your orginal comment:Geologists aren't stupid you know. There are ways to get a rough measure of the timescale of an event. As just one example, the speed of cooling of an igneous formation can be roughly gauged by looking at the size of the crystals in the rock. The larger the crystals, the slower the cooling.
You were repeating the widespread view that large crystals means long timescales. This view needs to be challenged and corrected - and that is what I did. You are right: geologists are not stupid. It is no reflection on the integrity of geologists to say that they also bring presuppositions to the data that affect their interpretation of it. My concern is with those who can't or won't agree with this comment. The example of magma cooling and crystallisation is a good one. For years, this was used as an argument for vast ages for granite crystalisation. Then laboratory studies started to show that the ages might not be so long. A recent study says that the time scale can be "years as opposed to millenia". Please note that I introduced the "recent study" by referring to "laboratory studies". Experimental petrology is a very interesting field - and it is based on the premise that laboratory findings can be related to phenomena in the natural world. The point I was making was that large crystals do not imply long timescales. We have known about this for over 20 years, but the message is taking a long time to take root. The paper I cited was the most recent that I have on file that makes the point. There are obviously other issues raised by the paper that I made no mention of - they are not relevant to the particular point under discussion.

[rogero]

To reiterate some posts on this thread, modern geology is not strictly uniformitarian but allows for catastrophic and rapid events, when such are the best explanations of the observed data. Thus, I don't see how this post is in support of a young earth vis-a-vis standard geology. A young-earther would need to show that ALL geological activity is rapid, which it most definitely is not.

[Monkey Boy]

You were repeating the widespread view that large crystals means long timescales. This view needs to be challenged and corrected - and that is what I did.

But you didn't challenge it at all. The abstract, let alone your quote, says nothing about crystal sizes. This excuse is starting to smell phony, David.

The point I was making was that large crystals do not imply long timescales. We have known about this for over 20 years, but the message is taking a long time to take root.

I know that's the point you want to make, but the quoted paper does not make it.

The paper I cited was the most recent that I have on file that makes the point. There are obviously other issues raised by the paper that I made no mention of - they are not relevant to the particular point under discussion.

Again, the paper does not make the point you want it to. You found a quote that sounded like it made your point, you mined it, and you disregarded the larger context of the paper.

[Acanthostega]

Geologists aren't stupid you know. There are ways to get a rough measure of the timescale of an event. As just one example, the speed of cooling of an igneous formation can be roughly gauged by looking at the size of the crystals in the rock. The larger the crystals, the slower the cooling.


Large crystals do not necessarily imply slow cooling. The largest crystals associated with granites are often found in narrow pegmatite veins – which must have cooled relatively quickly. Crystal size is determined by lots of factors (e.g. nucleation rate, pressure changes and amounts of volatiles) – not just the rate of cooling.

Experimental and theoretical research by petrologists has shown that plutonic textures can be formed in short periods of time. Plagioclase, orthoclase, and quartz have been grown in crystal forms and sizes characteristic of granite (Mustart, 1969; Swanson, 1977; Swanson et al, 1972). Plagioclase zoning (Lofgren, 1974), comb-layering (Lofgren and Donaldson, 1975), and mafic-before-felsic cyrystallization (Naney and Swanson, 1980) have all been simulated in the laboratory.

Swanson (1977, p.974) argues that the rapid crystallization of feldspar and quartz in these experiments 'suggests re-evaluation of the length of time required to produce the large crystals of the granitic rocks'.

Refs:

Lofgren G.E., 'Temperature induced zoning in synthetic plagioclase feldspar', in Mackenzie W.S., Zussman J. (editors), The Feldspars, Manchester University Press, 1974, pp.362-375.

Lofgren G.E., Donaldson C.H., 'Curved branching crystals and differentiation in comb-layered rocks', Contributions to Mineralogy and Petrology 1975;49:309-319.

Mustart D.A., 'Hydrothermal synthesis of large single crystals of albite and potassium feldspar', EOS 1969;50:675.

Naney M.T., Swanson S.E., 'The effect of Fe and Mg on crystallization in granitic systems', American Mineralogist 1980;65:639-653.

Swanson S.E., 'Relation of nucleation and crystal-growth rate to the development of granitic textures', American Mineralogist 1977;62:966-978.

Swanson S.E., Whitney J.A., Luth W.A., 'Growth of large quartz and feldspar crystals from synthetic granitic liquids', EOS 1972;53:1127.

[rogero]

Large crystals do not necessarily imply slow cooling. The largest crystals associated with granites are often found in narrow pegmatite veins – which must have cooled relatively quickly. Crystal size is determined by lots of factors (e.g. nucleation rate, pressure changes and amounts of volatiles) – not just the rate of cooling.

Experimental and theoretical research by petrologists has shown that plutonic textures can be formed in short periods of time. Plagioclase, orthoclase, and quartz have been grown in crystal forms and sizes characteristic of granite (Mustart, 1969; Swanson, 1977; Swanson et al, 1972). Plagioclase zoning (Lofgren, 1974), comb-layering (Lofgren and Donaldson, 1975), and mafic-before-felsic cyrystallization (Naney and Swanson, 1980) have all been simulated in the laboratory.

Swanson (1977, p.974) argues that the rapid crystallization of feldspar and quartz in these experiments 'suggests re-evaluation of the length of time required to produce the large crystals of the granitic rocks'.

Refs:

Lofgren G.E., 'Temperature induced zoning in synthetic plagioclase feldspar', in Mackenzie W.S., Zussman J. (editors), The Feldspars, Manchester University Press, 1974, pp.362-375.

Lofgren G.E., Donaldson C.H., 'Curved branching crystals and differentiation in comb-layered rocks', Contributions to Mineralogy and Petrology 1975;49:309-319.

Mustart D.A., 'Hydrothermal synthesis of large single crystals of albite and potassium feldspar', EOS 1969;50:675.

Naney M.T., Swanson S.E., 'The effect of Fe and Mg on crystallization in granitic systems', American Mineralogist 1980;65:639-653.

Swanson S.E., 'Relation of nucleation and crystal-growth rate to the development of granitic textures', American Mineralogist 1977;62:966-978.

Swanson S.E., Whitney J.A., Luth W.A., 'Growth of large quartz and feldspar crystals from synthetic granitic liquids', EOS 1972;53:1127.

Every freshman geology student knows that pegmatites are associated with high volatile content (esp. water) of magma. This does NOT imply that ALL phaneritic textures are associated with high volatiles and a short time frame of cooling. Deep rocks associated with the basement complexes and roots of old tectonic episodes are definitely not all pegmatitic.

Young-earthers need to demonstrate a method for rapid cooling of low-volatile magma that will produce phaneritic textures.

[dtyler]

Dave Hacker's Ph.D. dissertation (the source of the findings you are citing) was a triumph of traditional geology, as it combined meticulous field mapping, ceaseless stomping over the countryside, careful attention to subtle clues in the rocks, and meticulous working out of the details regarding temporal sequence and spatial arrangement. The main thing that Dave Hacker's dissertation makes us stop and think about is how good classical geological methods are and how much can be learned from very classical field work.

Yes, I am entirely happy with this. Geologists do have methodologies that work and credit is certainly due to DH for his achievements.

Dave, you are right that from Lyell until Hurricanes Donna and Camille and Harlan Bretz' triumph regarding the Channeled Scabland floods geologists had an overall bias against sudden and in favor of gradual. Basically this was an over-reaction against (1) Cuvier's catastrophism and, (2), more generally, against biblical geology of various stripes, both of which have been continual utter failures when measured against all incoming evidence since about 1820, combined with being extremely impressed with Lyell's Principles of Geology to the extent of exaggerating its uniformitarian themes.

Thanks. We are in agreement.

However, as Aniso said, geological classrooms are now full of information about inferred sudden kimberlite eruptions, rapid drainings of large lakes, rapid floodings of Black Seas and Mediterranean basins, sudden collapses of volcanoes, and so forth.

Dave, as I've said before on other threads you are fighting a view of geology that has had no basis in reality for the past 35 years. You have set up a strawman that does not exist.

I know you have said it before - and I have tried to respond by saying that I will not make blanket statements about uniformitarianism, but I will point out examples of uniformitarian thinking in those contributing to TheologyWeb. I have been driven to make further comments by specific examples of uniformitarian thinking. So, whilst I would welcome the situation if you were right, I am compelled to say that uniformitarianism is alive and well!

This thread has been a response to uniformitarianism: Glenn's thread on the Great Stone Dome is riddled with it. He simply does not have enough data to draw the conclusions he does. My response has been to post data about a stone dome that is undoubtedly a witness to catastrophism: this is not saying that *all* igneous domes are catastrophic, but it is saying that if one can be, so can others. We must do the necessary field work to reach a conclusion and deductions from theoretical principles can be highly misleading.

Are you saying that your geological colleagues here on TheologyWeb do not exhibit rather dated geological views on uniformitarianism? I know they give theoretical credence to the changes - but their mindset is strongly in the tradition of Lyell. For what it is worth, I do not include you in this comment - your contributions are distinctive because your thinking is empirically-led rather than deductive from theory. (Sorry if that offends anyone, but it is far milder than posted comments about my mindset!).

As a demonstration of this, it is hard fact that none of the geologists involved with or overseeing Dave Hacker's Ph.D. research were astonished by his inferences regarding rapid progression from landsliding through ash eruption to generation of lava flows, although everyone was impressed by how well he marshalled his evidence. No one involved with the research thought the rapidity was unthinkable, or that it broke any sacred uniformitarian paradigms. No one walked out of his dissertation defense in protest, and none of us thought about becoming a flood geologist as a consequence of his findings.

This is pleasing to know.

Dave Hacker also showed that these laccoliths happened in succession rather than all at once, and he showed that they happened a long time ago, not recently. I've forgotten what you consider to be post-flood, but you still have a heck of a lot of complex post-laccolith geologic events to find time for, even just in southern Utah. I don't think any justification exists for your claims that these "particular events would then be part of the post-Flood catastrophism affecting the North American continent", or that "the timescales indicated in my notes above are fully consistent" with such a scenario.

My thread starter referred to the successve emplacement of the laccoliths. My attempt to set these geologic events in an alternative geologic history was limited to a paragraph - it was to anticipate the response "So what? - what has this got to do with Flood geology". It was also to show that I do not treat geology as a series of isolated catastrophes, and do think about local, regional and global histories. But I also recognise that such comments open the door to reactions like yours. That is a risk I chose to take.

[Monkey Boy]

Large crystals do not necessarily imply slow cooling.

I do not disagree. My initial reference to crystal sizes was meant only as a general example and for rhetorical reasons excluded many of the qualifiers regarding the context in which the crystals are found. Your references serve to highlight the importance of that context.

[aniso]

Yes, I am entirely happy with this. Geologists do have methodologies that work and credit is certainly due to DH for his achievements.

Then why do YECs not apply the same methodology? Why do we see things like Brethault's experiments being trotted out as representative of the geological record? Why do we see Steve Austin collecting samples of historical basalt flows for radiometric dating? These efforts make a mockery of YECism.

I know you have said it before - and I have tried to respond by saying that I will not make blanket statements about uniformitarianism, but I will point out examples of uniformitarian thinking in those contributing to TheologyWeb.

The problem is that you HAVE to make blanket statements about uniformitarianism, otherwise all you've got is anecdotal information. If you are to make it a point that the universe is only 10ka old, you have to negate several entire bodies of geological work.

I have been driven to make further comments by specific examples of uniformitarian thinking. So, whilst I would welcome the situation if you were right, I am compelled to say that uniformitarianism is alive and well!

But not in the way you see it. No one here denies catastrophic events. Thousands, millions of them. We see them frequently in our own lifetimes and it is kind of hard to ignore. You are still fighting a battle that was over a century ago.

This thread has been a response to uniformitarianism: Glenn's thread on the Great Stone Dome is riddled with it. He simply does not have enough data to draw the conclusions he does.

You must live in an ivory tower, David. Most geophysicists I know are compelled by their jobs to draw conclusions and make recommendations. Not to sit back indefinitely and say, 'well, on the other hand...'.

My response has been to post data about a stone dome that is undoubtedly a witness to catastrophism: this is not saying that *all* igneous domes are catastrophic, but it is saying that if one can be, so can others. We must do the necessary field work to reach a conclusion and deductions from theoretical principles can be highly misleading.

And you will notice that no one here had a problem with that interpretation. The only problem we have is that you seem to have a predilection to extend any catastrophic event to EVERY geological event.

Are you saying that your geological colleagues here on TheologyWeb do not exhibit rather dated geological views on uniformitarianism?

LOL! That is a good one coming from you! After all, you are the only one fighting this battle still a century after the assualt on the Lyellian viewpoint.

I know they give theoretical credence to the changes - but their mindset is strongly in the tradition of Lyell.

Nonsense. We have just shown that we all like and even enjoy the catastrophic origin of the unroofed laccoliths in Utah. Are you saying that this was a Lyellian event?

For what it is worth, I do not include you in this comment - your contributions are distinctive because your thinking is empirically-led rather than deductive from theory. (Sorry if that offends anyone, but it is far milder than posted comments about my mindset!).

I am sorry, but if your reasoning here is the same as it is in your war against uniformitarianism, then I don't know if SedRocks should take that as a compliment. Are you saying that none of the rest of us rely upon experience and empirical evidence through decades of field work?

My thread starter referred to the successve emplacement of the laccoliths. My attempt to set these geologic events in an alternative geologic history was limited to a paragraph - it was to anticipate the response "So what? - what has this got to do with Flood geology". It was also to show that I do not treat geology as a series of isolated catastrophes, and do think about local, regional and global histories. But I also recognise that such comments open the door to reactions like yours. That is a risk I chose to take.

In that case, I am not sure what you point is here. Are you supporting a flood with the OP? If not, then perhaps you could make you point more clearly.

[aniso]

Originally Posted by Acanthostega
Large crystals do not necessarily imply slow cooling.

I do not disagree. My initial reference to crystal sizes was meant only as a general example and for rhetorical reasons excluded many of the qualifiers regarding the context in which the crystals are found. Your references serve to highlight the importance of that context.

There are several factors involved in the formation of crystals. Time is just one of them that David and Acanthostega have isolated. The real question is do we find all of these factors in nature, and at the scale they are observed in the field.

[grmorton]

This is not part of this thread - and animals were not walking around on Cambrian and Ordovician strata during the Flood.

By stating that animals weren't walking around on Cambrian and ordovician strata, you made it part of this thread. Here is a photo on Cambrian animal tracks. I can find Ordovician animal tracks as well but it shouldn't be necessary. This photo falsifies your viewpoint, David.

[attachment]



So, it is selective quotation to quote the first sentence of the author's abstract! The rest of the abstract deals with the burial of radioactive waste, so I cut it. I have seen another part of the paper quoted, but it says the same thing! The point I was making is a perfectly fair one and I have no reason to think that my use of the paper is selective. Here is a sentence in the quote posted earlier: it is exactly the point I was making.
Why is it that when the authors of the paper write those words, they are deemed to be engaging in scholarly activity, whereas when I write something similar and quote these authors, I am accused of quote mining?

No, you ripped that sentence way out of context.

Edited to add: In another note David makes the erroneous claim:

This thread has been a response to uniformitarianism: Glenn's thread on the Great Stone Dome is riddled with it. He simply does not have enough data to draw the conclusions he does.

David, you simply don't know what you are talking about. We had hundreds of thousands of miles of seismic data, oil well cuttings, oil well logs, paleontological reports, etc ad nauseum. I had more than enough evidence to claim what I did. You have never worked the East coast of the US professionally so you wouldn't have access to the data that I had access to.

[dtyler]

By stating that animals weren't walking around on Cambrian and ordovician strata, you made it part of this thread. Here is a photo on Cambrian animal tracks. I can find Ordovician animal tracks as well but it shouldn't be necessary. This photo falsifies your viewpoint, David.
Hardly. A "track" is a term reserved for things with legs. You have posted a "trail". If you had asked me, "what were animals doing making trails in the Cambrian and Ordovician?", I would have answered - participating in the recolonisation of the Earth after the Mabbul destruction. You need not post Ordovician trails - I have them in my own collection.

Regarding crystal sizes in cooling magma bodies:No, you ripped that sentence way out of context. I'm still waiting for an explanation from you or MonkeyBoy about this. Assertions do not demonstrate validity. Experimental igneous petrology repeatedly uses laboratory conditions to gain insights into natural processes. That paper explicitly refers to granitic magmas being "recrystallized on a time scale of years as opposed to millennia as widely believed." It is directly relevant to the comment MonkeyBoy made about inferring timescales from crystal size. It is also perfectly consistent with a significant body of literature that demonstrates that granitic sized crystals do not need even a decade to form. The long ages are *inferred* from the model of slow conductive cooling, not from the coarse crystaline structure.

David, you simply don't know what you are talking about. We had hundreds of thousands of miles of seismic data, oil well cuttings, oil well logs, paleontological reports, etc ad nauseum. I had more than enough evidence to claim what I did. You have never worked the East coast of the US professionally so you wouldn't have access to the data that I had access to.
Seismics and bore holes give good data about structure - which is why the work is done. The issue of interpreting the data in terms of a geologic history is far more demanding. It is easy for theory to substitute for empirical evidence.

[grmorton]

Hardly. A "track" is a term reserved for things with legs. You have posted a "trail". If you had asked me, "what were animals doing making trails in the Cambrian and Ordovician?", I would have answered - participating in the recolonisation of the Earth after the Mabbul destruction. You need not post Ordovician trails - I have them in my own collection.

And they were made while a raging global flood was going on? David, come back to this universe. Your semantic quibble is nothing more than an escape mechanism for you. A way to avoid the consequences of fining TRAILS which had to be made in a calm environment, in the middle of your global flood.
You are becoming as slippery as Tony Blair.

Regarding crystal sizes in cooling magma bodies: I'm still waiting for an explanation from you or MonkeyBoy about this. Assertions do not demonstrate validity. Experimental igneous petrology repeatedly uses laboratory conditions to gain insights into natural processes. That paper explicitly refers to granitic magmas being "recrystallized on a time scale of years as opposed to millennia as widely believed."

Come on David. The granite was heated JUST above the melting point and then allowed to cool to just below it. Of course it crystalized rapidly because it didn't need to cool from a gazillion degrees of hot.

Seismics and bore holes give good data about structure - which is why the work is done. The issue of interpreting the data in terms of a geologic history is far more demanding. It is easy for theory to substitute for empirical evidence.

This shows you don't have the foggiest clue to what one has in Seismic, not seismics, and bore holes. They give much more than structure. The bore hole gives you rocks and fossils. These microfossils are found in the same order throughout the world's oceans--everywhere!!!. So they can be used for correlation since no YEC has ever given an explanation for why the raging global flood would sort microscopic animals based upon their skeleton shapes (which aren't exposed when the animal or plant is alive) see http://home.entouch.net/dmd/micro.htm

Seismic data gives one information on structure, yes, but it also gives information on time sequence in geology. I explain this (and you should know better, but don't want to see it) at http://home.entouch.net/dmd/seismic.htm

David, you have never interpreted a seismic line in your life. How can you say interpreting the data is more demanding? Basically, it requires the AMAZING ability to stay within the lines. One gets on a seismic reflection and draws a colored line mapping that particular reflections extent. Kindergarten kids could do it.

And the fact is, at the Great Stone dome, the beds which are cooked by the Great Stone Dome intrusion, are above the cooking down in SE Georgia Embayment. This means there are two cooking events. It isn't hard, and requires the skill of a kindergartener to see this.

[dtyler]

And they were made while a raging global flood was going on? David, come back to this universe. Your semantic quibble is nothing more than an escape mechanism for you. A way to avoid the consequences of fining TRAILS which had to be made in a calm environment, in the middle of your global flood.
You are becoming as slippery as Tony Blair.
Glenn, you keep firing at the wrong targets. You are the one who injected the word "raging global flood". the "raging" part was the Mabbul - the first 40 days. In the Recolonisation model, this is the Hadean, moving into the Archaean. After that, signs of recolonisation are widespread - and that includes trails and burrows. What is a semantic quibble to you is basic ichnological terminology to me. I assume that when a geologist uses terms to describe geological phenomenon, those terms have a particular meaning. If words mean what the author thinks they mean, then we really are on the slippery slope.

Come on David. The granite was heated JUST above the melting point and then allowed to cool to just below it. Of course it crystalized rapidly because it didn't need to cool from a gazillion degrees of hot.
Of course, any rock will cool quickly if conditions allow it. In experimental petrology, this is routine. After quenching, the rapidly solidified melt becomes a glass. The important thing in this paper is that the granitic texture was obtained quickly - getting the crystalline texture was an important part of the exercise. That granitic texture is not a sign of long timescales. I am still waiting for an explanation as to why this is taking the words of the abstract out of context.

Seismic data gives one information on structure, yes, but it also gives information on time sequence in geology. I explain this (and you should know better, but don't want to see it) at http://home.entouch.net/dmd/seismic.htm

Sequence is part of structure. My points are concerned with timescales - establishing a sequence is one challenge and interpreting that sequence in terms of geologic processes and timescales is another.

[SteveF]

Glenn, you keep firing at the wrong targets. You are the one who injected the word "raging global flood". the "raging" part was the Mabbul - the first 40 days. In the Recolonisation model, this is the Hadean, moving into the Archaean. After that, signs of recolonisation are widespread - and that includes trails and burrows. What is a semantic quibble to you is basic ichnological terminology to me. I assume that when a geologist uses terms to describe geological phenomenon, those terms have a particular meaning. If words mean what the author thinks they mean, then we really are on the slippery slope.
Is this the same Hadean and Archean during which the earth was being bombarded with meteorites? Is this the same Archean that consisted of a reducing atmosphere of methane and ammonia? Doesn't sound like a suitable environment for the beasties that wander out an recolonise (not to mention the huge ecoligical problems with such recolonisation).

Oh and wouldn't this require the entire earths surface to cool and form plates (as they did in this time) in 40 days. Even taking into account a tweak in timescales its a bit daft.

Sequence is part of structure. My points are concerned with timescales - establishing a sequence is one challenge and interpreting that sequence in terms of geologic processes and timescales is another.We have radiometric dates (shown time and time again to be relaible) to aid us in interpreting timescales. They seem to contradict your beliefs somewhat!

There is no logical reason to assume (as you seem to do) that because somethings happen quickly, then therefore all processes must. This is ad hoc thinking to support an existing prejudice.

Edited to add a bit about ecology

[Monkey Boy]

Regarding crystal sizes in cooling magma bodies: I'm still waiting for an explanation from you or MonkeyBoy about this. Assertions do not demonstrate validity. Experimental igneous petrology repeatedly uses laboratory conditions to gain insights into natural processes. That paper explicitly refers to granitic magmas being "recrystallized on a time scale of years as opposed to millennia as widely believed." It is directly relevant to the comment MonkeyBoy made about inferring timescales from crystal size.

It's not relevant for two reasons:
1) It makes no mention of crystal size, which the whole basis of my original claim.
2) The experiment was placed in a very specific context -- the disposal of radioactive waste in boreholes. It is not at all clear that the results are relevant in natural settings and at the scale observed in natural formations. (thanks aniso!)

It is also perfectly consistent with a significant body of literature that demonstrates that granitic sized crystals do not need even a decade to form. The long ages are *inferred* from the model of slow conductive cooling, not from the coarse crystaline structure.

This brings us back to the point I originally intended to convey. The slow cooling model makes predictions which can be tested. Your implication that scientists are content to accept models without testing them is rather offensive. Maybe we ought to turn the tables. Is your hypothesis of a young earth just an *inference* from the biblical creation model, or have you tested its predictions and found them to be true? If so, please share your findings as I think we would all be quite impressed.

Seismics and bore holes give good data about structure - which is why the work is done. The issue of interpreting the data in terms of a geologic history is far more demanding. It is easy for theory to substitute for empirical evidence.

We're still waiting for that empricial evidence for a global flood. Does the hypocrisy of your own comments totally escape you?

[dtyler]

Is this the same Hadean and Archean during which the earth was being bombarded with meteorites?
Yes. The Earth was being destroyed and all air-breathing creatures were wiped out - saving only those on the ark.

Is this the same Archean that consisted of a reducing atmosphere of methane and ammonia?
You are about 30 years out of date here. There is no evidence that the Earth's atmosphere was ever reducing. You are repeating one of the "origins myths" of our time.

Doesn't sound like a suitable environment for the beasties that wander out an recolonise (not to mention the huge ecoligical problems with such recolonisation).
That's right. It was an environment that was hostile to life. Recolonisation came later.

Oh and wouldn't this require the entire earths surface to cool and form plates (as they did in this time) in 40 days. Even taking into account a tweak in timescales its a bit daft.
There are lots of assumptions built into this comment. Remember that the Earth before the Mabbul was habitable according to biblical history - whereas the evolutionary scenario has quite a different approach.

We have radiometric dates (shown time and time again to be relaible) to aid us in interpreting timescales. They seem to contradict your beliefs somewhat!
Yes they do contradict. I fully accept that.

There is no logical reason to assume (as you seem to do) that because somethings happen quickly, then therefore all processes must. This is ad hoc thinking to support an existing prejudice.

I have said repeatedly that this is not the argument of this thread. It has never been an argument I have used.

[SteveF]

Yes. The Earth was being destroyed and all air-breathing creatures were wiped out - saving only those on the ark.
And er, how exactly did the ark survive this incredibly harsh world?

You are about 30 years out of date here. There is no evidence that the Earth's atmosphere was ever reducing. You are repeating one of the "origins myths" of our time.
All the signs seem to show a very harsh environment. Its not a subject I'm hugely familiar with, but a quick search found a fair bit. For example, from Precambrian Research, 104, 147-174, 2000:

Ba depletion seems to have been especially characteristic of chemical weathering during 2.35-2.2 Ga under CO2-rich and low-O-2 atmosphere

How exactly did Noah survive this?

Oh and shortly after the archean, around 2.4 to 2.2 million years ago the earths first glaciation occured (Erikkson et al 2001, Sedimentary Geology, 141, 1-35). It was quite frankly cold and yet life was able to start up quite happily, warm adapted species and all in the radically different earth system that a glacial poses. Oh and a glaciation takes a long time. You can't grow an ice sheet in a few hundred years.

That's right. It was an environment that was hostile to life. Recolonisation came later.
You miss my point. Ecologically recolonisation has problems as i alluded to in an earlier thread regarding sucession. Ecologically theory just can't be generalised as widely as you would like.

There are lots of assumptions built into this comment. Remember that the Earth before the Mabbul was habitable according to biblical history - whereas the evolutionary scenario has quite a different approach.
So it was habitable, suddenly turned into the hadean and archean (for which a substantial portion of time the earth was thought to be molten) then truned back again. In 40 days.

Yes they do contradict. I fully accept that.
Then why do you persist in thinking the earth is young? Are you just ignoring data that is perfectly valid (as radiometric dating is) just to fit preconcieved notions. Thats pretty ad hoc.

I have said repeatedly that this is not the argument of this thread. It has never been an argument I have used.
Not used directly maybe, but if the earth is a few thousand years old then processes have to have been occuring quickly.

[Avatar_of_evil]

You are about 30 years out of date here. There is no evidence that the Earth's atmosphere was ever reducing. You are repeating one of the "origins myths" of our time.

Well you can argue over the evidence but it is a lie to say such evidence does not exist.

[rogero]

...
You are about 30 years out of date here. There is no evidence that the Earth's atmosphere was ever reducing. You are repeating one of the "origins myths" of our time.

...


I guess I am 30 years out of date in my geology knowledge, since that's when I took my geo coursework. So the time sequence of No Fe in paleosols --> BIF --> Red beds is no longer accepted as evidence of transition from a reducing to an oxidizing atmosphere?

Just curious...

Also...

... All the signs seem to show a very harsh environment. It's not a subject I'm hugely familiar with, but a quick search found a fair bit. For example, from Precambrian Research, 104, 147-174, 2000:

Ba depletion seems to have been especially characteristic of chemical weathering during 2.35-2.2 Ga under CO2-rich and low-O-2 atmosphere
...


Doesn't low O2 mean reducing?

[Kulindrichnus]

the "raging" part was the Mabbul - the first 40 days. In the Recolonisation model, this is the Hadean, moving into the Archaean.

REcolonization??

There's not a scrap of geological evidence for pre-Hadean colonization of anything. There isn't even a pre-Hadean earth to colonize in the first place, and evidence for the Hadean itself is scant- the system is best preserved on the moon!

Would I be right if I guess you're going to tell us that all the pre-flood (i.e., pre-Hadian) faunas were melted up in a global fireball during Noah's meteor bombardment and that's why we don't realize about the pre-hadean earth and its' garden of eden?

What is a semantic quibble to you is basic ichnological terminology to me.

Anyone wishing to assess David's ichnological skills (e.g. arbitarily informing me that the ichnogenus Thalassinoides was represented by a single species on the basis of no investigative work at all, overlooking the presence of Rhizocorallium and annelid encrustations as recorded in his own references, etc) might like to refer to the Filey Brigg thread, where, as usual, David's progress may be reconstructed using methodological naturalism and the ubiquitous paper-trail of unanswered questions.

K

[Roy]

Hardly. A "track" is a term reserved for things with legs.

Tyres have legs?

There may be a legs v. no-legs distinction in paleontology, but in non-technical areas the distinction is definitely continuous/regular v. sporadic/irregular, e.g. railway tracks <-> nature trails, animal tracks <-> game trails, vehicle tracks <-> paper trails, worm-tracks <-> scent trails etc.



Roy

[kuboes1831]

Can one do any geology without some kind of principle of uniformity.

Orthodox geologists do thsi with care

YEC"geologists" (oxymoron) either adopt an ultra-extreme uniformitarianism which neither Lyell or Darwin ever held, so just come out with vain babblings

[aniso]

Regarding crystal sizes in cooling magma bodies: I'm still waiting for an explanation from you or MonkeyBoy about this. Assertions do not demonstrate validity. Experimental igneous petrology repeatedly uses laboratory conditions to gain insights into natural processes. That paper explicitly refers to granitic magmas being "recrystallized on a time scale of years as opposed to millennia as widely believed."

You have a problem here, David. It is not possible to 'recrystallize a magma'.

Also, did anyone notice that this paper talks about 'recrystallization' and not crystallization? There IS a difference.

It is directly relevant to the comment MonkeyBoy made about inferring timescales from crystal size. It is also perfectly consistent with a significant body of literature that demonstrates that granitic sized crystals do not need even a decade to form.

What the heck is a 'granitic sized crystal'? And no, you have not yet shown this.

The long ages are *inferred* from the model of slow conductive cooling, not from the coarse crystaline structure.

Please show us evidence that a batholith has cooled in a few years. I don't recognize recrystallization experiments as being evidence for this.

Also, I seem to remember a few years ago how YECs touted the fact that granites could not be formed in the laboratory. This was supposed to be evidence of divine creation. How do you square that statement with your current stand?

Seismics and bore holes give good data about structure - which is why the work is done. The issue of interpreting the data in terms of a geologic history is far more demanding. It is easy for theory to substitute for empirical evidence.

Then you have an explanation of the geological history for all of the seismic data that Glenn has presented? Why are you holding out on us?

[grmorton]

Glenn, you keep firing at the wrong targets. You are the one who injected the word "raging global flood". the "raging" part was the Mabbul - the first 40 days. In the Recolonisation model, this is the Hadean, moving into the Archaean. After that, signs of recolonisation are widespread - and that includes trails and burrows.

Bull roar. You get negative points for knowing your own viewpoint. I had written in the post above this one on Oct 17, 2003 http://www.theologyweb.com/forum/showthread.php?s=&postid=248035#post248035 :

David, WHERE do YOU think the end of the flood is? I don't care where OTHER recolonists think it is. Answer with a simple answer, that question. Give me a geologic period or era, epoch or stage.

You replied:
Since you ask me for my personal view, I'll give it. I do not think it particularly important in the context of all the other matters we've discussed. I put it at the end of the Ordovician.

So don't give me a different, slippery story today. In October the flood extended until the Ordovician, Today it is only until the Archaean. You change your story with the change of days. That is not science, but snake oil.




What is a semantic quibble to you is basic ichnological terminology to me. I assume that when a geologist uses terms to describe geological phenomenon, those terms have a particular meaning. If words mean what the author thinks they mean, then we really are on the slippery slope.

You are just using a semantic quibble to divert attention to the fact that there should be no tracks, trails, insect burrows, invertebrate burrows (homes, nests or whatever you wish to call them) during the middle of the global flood, which you said ended in the Ordovician in October and now you claim ended in the Archaean. One has the slip-sliding away feeling for the global flood.

Of course, any rock will cool quickly if conditions allow it. In experimental petrology, this is routine. After quenching, the rapidly solidified melt becomes a glass. The important thing in this paper is that the granitic texture was obtained quickly - getting the crystalline texture was an important part of the exercise. That granitic texture is not a sign of long timescales. I am still waiting for an explanation as to why this is taking the words of the abstract out of context.

And you wonder why no one takes you seriously.



Sequence is part of structure. My points are concerned with timescales - establishing a sequence is one challenge and interpreting that sequence in terms of geologic processes and timescales is another.

You are so unknowledgeable in geology and its workings that it is laughable, but sad at the same time. You continually tie falsehood to the Bible, like a cruel child ties a tin can to the cat's tail. A structure is defined by words like 'anticline', 'syncline', 'erosional truncation', 'pinch out', 'faulted.' Sequence is defined with words like, 'before,' 'during', 'after'. You are probably thinking of sequence stratigraphy, but even there that is a set of markers of lowstands and high stands of the sealevel. These surfaces have structure, but they also have sequence---one is older than the other.

David, you have a serious problem admitting that you are wrong.

[aniso]

Of course, any rock will cool quickly if conditions allow it. In experimental petrology, this is routine. After quenching, the rapidly solidified melt becomes a glass. The important thing in this paper is that the granitic texture was obtained quickly - getting the crystalline texture was an important part of the exercise.

Excuse me. I saw nothing regarding the development of a 'granitic texture' in a very short time, only evidence for rapid recrystallization under some very specific conditions. David, you are getting farther and farther from reality here. Have you actually read this paper? Do you have any other/better examples of rapidly forming granitic textures?

That granitic texture is not a sign of long timescales. I am still waiting for an explanation as to why this is taking the words of the abstract out of context.

David, I am willing to entertain real evidence in you favor. But you are not giving us much to work with.

[Kulindrichnus]

So don't give me a different, slippery story today. In October the flood extended until the Ordovician, Today it is only until the Archaean. You change your story with the change of days. That is not science, but snake oil.

It is quite ironic in this light that the end-ordovician is a MFS....

[grmorton]

It is quite ironic in this light that the end-ordovician is a MFS....

Oh what a laugh. I hadn't picked up on that. Thanks. I wonder if David knows what an MFS is and more importantly what the implications are to his viewpoint? He certainly doesn't appreciate the implications of trails to his viewpoint.

[Roy]

It is quite ironic in this light that the end-ordovician is a MFS....

WTF is MFS? RSVP PDQ. IMO, PLU use FTM TLAs.

TTFN,

R.

[rogero]

WTF is MFS? RSVP PDQ. IMO, PLU use FTM TLAs.

TTFN,

R.


R, FYI: Maximum Flooding Surface, IIRC

R

[dtyler]

It's not relevant for two reasons:
1) It makes no mention of crystal size, which the whole basis of my original claim.
2) The experiment was placed in a very specific context -- the disposal of radioactive waste in boreholes. It is not at all clear that the results are relevant in natural settings and at the scale observed in natural formations. (thanks aniso!)

I'm persisting with this because I completely reject the claim that this paper is not relevant to understanding timescales associated with the coarse grain size of granites. Monkey Boy raised the subject - suggesting that coarse grain size implies long timescales.

Regarding this paper from Geology, of course the paper makes mention of grain size! The abstract would lead us to think that, and the text certainly does. It is worth pointing out that “crystallization” is one of the keywords linked to the abstract.

Crystallization is important to the paper. It is vital for storing nuclear waste that “the melt slowly cools and recrystallizes to seal the packages into a sarcophagus of solid granite surrounded by zones of thermal metamorphism in which any pre-existing fractures are sealed by annealing and low temperature hydration mineralization”. It is important for two reasons. “First, sufficient melting of the granite will occur at low enough temperatures for the containers to survive, and second, the partial melt to be completely recrystallized to a fine- to medium-grained holo-crystalline rock – both on timescales appropriate to the thermal decay of the waste."

In this context, the words previously posted are very significant. “Cooling rates deduced from natural granite bodies have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years but there are grounds for believing that acid (silica-rich) magmas can be completely crystallized at cooling rates orders of magnitude faster.”

The experimental work (Figure 4) shows granitic melts, with different water contents and different rates of cooling, showing cooling from 800 degrees Centigrade to about 550 degrees. At 1 degree C per day, the slowest cooling rate, complete crystallization was achieved in 270 days.

The authors write: “Particularly significant in the context of such schemes are the cooling experiments carried out on cores of solid granite that confirmed that the partial melts can be recrystallized (Fig. 5), but demonstrated that the silicate liquids will flow into any fractures in the rock before sealing them completely on recrystallization.” (Fig 5 shows a thin section of granite that had cooled from 800 deg C to 560 deg C at 0.1 degC/h. It shows that there is complete recrystallization – no glass).

So, what do I make of the statement: "It is not at all clear that the results are relevant in natural settings and at the scale observed in natural formations." Unless you are arguing that the laws of physics and chemistry are changing depending on the "setting", the findings are directly relevant. Granitic textures do not imply timescales longer than, say a year or two. You cannot "see deep time" in these textures. You can interpret long timescales if you first assume a certain model of emplacement of the granite - but that is another story. It is not the issue raised by Monkey Boy.

This brings us back to the point I originally intended to convey. The slow cooling model makes predictions which can be tested. Your implication that scientists are content to accept models without testing them is rather offensive.

This sounds rather like backtracking. You made a statement linking granite crystal size to timescales - and I have said this can be tested and it proves false. I also quoted from a paper that freely acknowledges that a "widely held belief" about granite crystallization is out by "orders of magnitude". This has been known for over 30 years, yet people still retain the outdated view - yourself included. I think I know why this is - but you can speak for yourself. I do not want to sound "rather offensive"! Why have you persisted with holding this view when the experimental work to test the claim has shown the belief to be wrong?

[rach12]

The authors write: “Particularly significant in the context of such schemes are the cooling experiments carried out on cores of solid granite that confirmed that the partial melts can be recrystallized (Fig. 5), but demonstrated that the silicate liquids will flow into any fractures in the rock before sealing them completely on recrystallization.” (Fig 5 shows a thin section of granite that had cooled from 800 deg C to 560 deg C at 0.1 degC/h. It shows that there is complete recrystallization – no glass).

So, what do I make of the statement: "It is not at all clear that the results are relevant in natural settings and at the scale observed in natural formations." Unless you are arguing that the laws of physics and chemistry are changing depending on the "setting", the findings are directly relevant. Granitic textures do not imply timescales longer than, say a year or two. You cannot "see deep time" in these textures. You can interpret long timescales if you first assume a certain model of emplacement of the granite - but that is another story. It is not the issue raised by Monkey Boy.


But David, isn't there a world of difference between the partial melting and REcrystaillization of a granite core and the cooling rate of a magma chamber emplaced at depth?

[geochron]

Crystallization is important to the paper. It is vital for storing nuclear waste that “the melt slowly cools and recrystallizes to seal the packages into a sarcophagus of solid granite surrounded by zones of thermal metamorphism in which any pre-existing fractures are sealed by annealing and low temperature hydration mineralization”. It is important for two reasons. “First, sufficient melting of the granite will occur at low enough temperatures for the containers to survive, and second, the partial melt to be completely recrystallized to a fine- to medium-grained holo-crystalline rock – both on timescales appropriate to the thermal decay of the waste."


These are the premises on which the proposed disposal scheme is based, yes. The paper sets out to investigate whether they are met when radioactive waste is buried in granite.



In this context, the words previously posted are very significant. “Cooling rates deduced from natural granite bodies have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years but there are grounds for believing that acid (silica-rich) magmas can be completely crystallized at cooling rates orders of magnitude faster.”



The quote I've found says...


"Cooling rates of natural granites have been deduced from the times taken for the intrusions in which they occur to cool from their emplacement temperatures, but such times (derived by various techniques) have indicated cooling rates mostly in the range 10–500 8C/m.y. (Attrill and Gibb, 2003b). These have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years. There are, however, good grounds for believing that silicic magmas can be completely crystallized at cooling rates orders of magnitude faster." (Page 658, collumn 2)


I think the thing you're overlooking here is the question of how much a granite that is partially melted and recrystallised resembles a granite found in nature.

"There are, however, good grounds for believing that silicic magmas can be completely crystallized at cooling rates orders of magnitude faster".

Perhaps these geologists were being a little ironic here - if I recall my introductory geology, a silicic melt that cools quickly produces a fine grained rock called a rhyolite.


The authors write: “Particularly significant in the context of such schemes are the cooling experiments carried out on cores of solid granite that confirmed that the partial melts can be recrystallized (Fig. 5), but demonstrated that the silicate liquids will flow into any fractures in the rock before sealing them completely on recrystallization.” (Fig 5 shows a thin section of granite that had cooled from 800 deg C to 560 deg C at 0.1 degC/h. It shows that there is complete recrystallization – no glass).

So, what do I make of the statement: "It is not at all clear that the results are relevant in natural settings and at the scale observed in natural formations." Unless you are arguing that the laws of physics and chemistry are changing depending on the "setting", the findings are directly relevant. Granitic textures do not imply timescales longer than, say a year or two. You cannot "see deep time" in these textures. You can interpret long timescales if you first assume a certain model of emplacement of the granite - but that is another story. It is not the issue raised by Monkey Boy.



Perhaps you should have quoted this bit as well...


To avoid the well-known nucleation problems in granitic systems (Naney and Swanson, 1980), it is essential that seed crystals be present in the melt. Usually this is achieved experimentally by incorporating large pieces of the seed phase in the starting material (Scaillet et al., 1995; Simakin and Chevychelov, 1995). In our experiments this was unnecessary; before cooling, the starting materials were run at 800 deg C for 624 h such that only a partial melt was generated. Hence, the seeds were already present as relict crystals, exactly as they would be in the disposal schemes.


Which rather calls into question the relevance of the experiments to a cooling intrusion.

Also, typical grain sizes (from Fig 5) in the melt look to be around 0.5 mm or less - well into the texture size geologists associate with quick cooling anyway iirc. Maybe a real geologist can set me straight, but wouldn't a rock with the composition of a granite that was this fine grained be called a rhyolite? And aren't they classified as extrusive rocks because they are thought to have cooled quickly...

It is far from clear to me how this paper, which is dealing with how fast a granite that has been partially melted can be cooled and still yield a crystalline rock rather than a glass, has anything to do with the cooling rates of coarse-grained granites that formed from total melts.


This sounds rather like backtracking. You made a statement linking granite crystal size to timescales - and I have said this can be tested and it proves false.


Perhaps, but this paper neither addresses nor proves any such thing, I'm afraid. It says nothing whatsoever about the dependence of grain size on cooling rate. It does however show that fast cooling yields small crystals.

You seem to be working on the assumption that a recrystallised granitic melt is the same things as a granite no matter what the crystal size.

[aniso]

I think the thing you're overlooking here is the question of how much a granite that is partially melted and recrystallised resembles a granite found in nature.

As far as I know, a good petrologist can tell annealing and recrystallization textures in a granite. I wonder if David, thinks all natural granites have such textures.

[rach12]

Regarding this paper from Geology, of course the paper makes mention of grain size! The abstract would lead us to think that, and the text certainly does. It is worth pointing out that “crystallization” is one of the keywords linked to the abstract.

David, this paper only barely touches on grain size. The abstract makes absolutely no mention of grain size and only the word "recrystallized" appears.


Crystallization is important to the paper. It is vital for storing nuclear waste that “the melt slowly cools and recrystallizes to seal the packages into a sarcophagus of solid granite surrounded by zones of thermal metamorphism in which any pre-existing fractures are sealed by annealing and low temperature hydration mineralization”. It is important for two reasons. “First, sufficient melting of the granite will occur at low enough temperatures for the containers to survive, and second, the partial melt to be completely recrystallized to a fine- to medium-grained holo-crystalline rock – both on timescales appropriate to the thermal decay of the waste."

David, I read the paper and did not get out of it what you did.

Namely, the quotes above are describing a proposed scheme (Gibb's own idea referenced in a prior paper from 2000) that would be necessary to safely and securely store radioactive waste. Those quotes you presented are NOT conclusions of this or any other study.

Gibb suggests that the safest method to store radioactive waste would be to place the waste at the bottom of 4 - 5 km deep boreholes drilled into granite. As the waste decays, heating up the surrounding granite, partial melting would occur. As the heat output from the waste decreases, the granite melt would slowly cool and recrystallize - sealing the waste in a "sarcophagus of solid granite." Additionally, this SCHEME, in order to work, would require sufficient melting at the temperatures produced by the decaying waste (in order to encase the containers), as well as for the melt to recrystallize to a fine- or medium-grained holocrystalline rock - all in a specific amount of time, namely a few years.

This study, on the other hand, did manage to produce crystalline rock instead of glass, but it did not produce medium-grained granite as you seem to suggest. Grain sizes are on the order of ~0.3 mm, three times too small to be considered medium-grained. They are more on the order of very fine-grained to fine-grained.

As far as I can see, these types of studies are interesting, but I fail to see any real relevance to naturally occuring granitic plutons... at this time.

Perhaps you could suggest another paper???

[Monkey Boy]

I'm persisting with this because I completely reject the claim that this paper is not relevant to understanding timescales associated with the coarse grain size of granites. Monkey Boy raised the subject - suggesting that coarse grain size implies long timescales.

I just want to note that I do not claim that coarse grain size must imply long time scales. The context of the formation is vitally important, and such a conclusion is only valid in some contexts.

In this context, the words previously posted are very significant. “Cooling rates deduced from natural granite bodies have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years but there are grounds for believing that acid (silica-rich) magmas can be completely crystallized at cooling rates orders of magnitude faster.”

The paper presents the results of an experiment to see if granitic magma can fully recrystallize at "fast" cooling rates and with certain magma chemistry. The question is, are the "fast" cooling rates and magma chemistry used in the experiment applicable to the scale and type of natural formations we see? Given the conditions outlined in the paper, I think it's not at all obvious that these results have any relevance at all. Hence my charge of quote mining.

So, what do I make of the statement: "It is not at all clear that the results are relevant in natural settings and at the scale observed in natural formations." Unless you are arguing that the laws of physics and chemistry are changing depending on the "setting", the findings are directly relevant.

No need to change physics or chemistry to make the results irrelevant, just the cooling rates, magma chemistry, and heating profile. If you can explain how it is possible for a massive magma chamber to cool at rates of 0.1 degC/hr, if you can show how the chemistry of the tested magma is representative of most granite formations, and if you can show that most granite formations were only partially and not totally melted, then you might have a point.

Granitic textures do not imply timescales longer than, say a year or two.

Only if one cannot make a reasonable model of the process of formation and the cooling rate.

You can interpret long timescales if you first assume a certain model of emplacement of the granite - but that is another story. It is not the issue raised by Monkey Boy.

But this is exactly the issue I raised. Of course scientists have a model of the emplacement of the granite. No "assuming" is required, as the model is yet another result of observation and hypothesis testing. I can see how you'd like to ignore the emplacement model, as that presents its own problems for your YEC views, but it is irresponsible to do so from a scientific perspective.

This sounds rather like backtracking. You made a statement linking granite crystal size to timescales - and I have said this can be tested and it proves false.

I made a statement saying that crystal size was one observation that can be indicative of long timescales. I had assumed the reader would understand that conclusion is dependent upon a large number of other observations and well-tested hypotheses. I guess I assumed wrong.

I also quoted from a paper that freely acknowledges that a "widely held belief" about granite crystallization is out by "orders of magnitude".

Read that sentence in the paper again. There was a belief that granite couldn't crystallize faster than it does in nature. Turns out, under specific artificial conditions, it can.

This has been known for over 30 years, yet people still retain the outdated view - yourself included. I think I know why this is - but you can speak for yourself. I do not want to sound "rather offensive"! Why have you persisted with holding this view when the experimental work to test the claim has shown the belief to be wrong?

To be honest, until you brought it up, I never thought about how fast granite can crystallize. I have no reason to doubt the experimental results and I thank you for the education.

[dtyler]

David, this paper only barely touches on grain size. The abstract makes absolutely no mention of grain size and only the word "recrystallized" appears.

The paper declares two issues that the authors wanted to explore: “First, sufficient melting of the granite will occur at low enough temperatures for the containers to survive, and second, the partial melt to be completely recrystallized to a fine- to medium-grained holo-crystalline rock – both on timescales appropriate to the thermal decay of the waste." Both are important for the proposed waste disposal method to work. Rather than barely touching on grain size, the paper reports experimental data to show that the second requirement is confirmed.

David, I read the paper and did not get out of it what you did.
Namely, the quotes above are describing a proposed scheme (Gibb's own idea referenced in a prior paper from 2000) that would be necessary to safely and securely store radioactive waste. Those quotes you presented are NOT conclusions of this or any other study.
This comment is a mystery to me. The authors wrote their paper because they had some significant conclusions - and the conclusion on crystallisation is the one I've been citing.

This study, on the other hand, did manage to produce crystalline rock instead of glass, but it did not produce medium-grained granite as you seem to suggest. Grain sizes are on the order of ~0.3 mm, three times too small to be considered medium-grained. They are more on the order of very fine-grained to fine-grained.
It produced "fine- to medium-grained holocrystalline rock". All that holocrystalline means is that the rock is wholly crystalline with no glass.

As far as I can see, these types of studies are interesting, but I fail to see any real relevance to naturally occuring granitic plutons... at this time.
Perhaps you could suggest another paper???
Crystallisation rates are a matter of physics and chemistry - they *have* to be relevant to naturally ocurring "plutons". If you believe granites are emplaced as large plutons, it would be expected that cooling would be slow. The point I was picking up was that information re long cooling times can be extracted from the granitic texture. This is where the paper I cited is relevant. The belief in long cooling times is model dependent, and does not emerge from the physics of granite crystallisation.

There are numerous other papers - this just happened to be a convenient example. Acanthostega has helpfully posted references to several others.

In my 1990 ICC paper on "A tectonically controlled rock cycle", I have a section on "Crystal growth in magmatic fluids" that makes the same point. I quote Luth, W.C. "Granitic rocks", in Bailey and Macdonald (eds), "The evolution of the crystalline rocks", Academic Press, 1976, 333-417. He says: "It is frequently assumed that the presence of large crystals in these phases implies slow growth over long periods of time. Although this may be the case, the intent here is to demonstrate that it does not necessarily hold" (p.405). This is exactly the point I have been making, and I see the "Geology" paper last year as yet another confirmation of this same basic point.

[geochron]

The paper declares two issues that the authors wanted to explore: “First, sufficient melting of the granite will occur at low enough temperatures for the containers to survive, and second, the partial melt to be completely recrystallized to a fine- to medium-grained holo-crystalline rock – both on timescales appropriate to the thermal decay of the waste." Both are important for the proposed waste disposal method to work. Rather than barely touching on grain size, the paper reports experimental data to show that the second requirement is confirmed.



I've just read it again - they don't actually comment on the grain size at all afaics.


This comment is a mystery to me. The authors wrote their paper because they had some significant conclusions - and the conclusion on crystallisation is the one I've been citing.


Their conclusion is that it recrystallises, but they don't say anything about its grain size. Figure 5 suggests the grain size is fine.


It produced "fine- to medium-grained holocrystalline rock". All that holocrystalline means is that the rock is wholly crystalline with no glass.


In your quote you're confusing what they specify as required by the application with the results they got. Would you mind pointing out by page/column or quoting the passage where they discuss the grain size of the recrystallised material because I can't find it.


Crystallisation rates are a matter of physics and chemistry - they *have* to be relevant to naturally ocurring "plutons". If you believe granites are emplaced as large plutons, it would be expected that cooling would be slow. The point I was picking up was that information re long cooling times can be extracted from the granitic texture. This is where the paper I cited is relevant. The belief in long cooling times is model dependent, and does not emerge from the physics of granite crystallisation.


The paper has nothing to do with this - the experiments produced small crystals as the model Monkey Boy advances would predict.


In my 1990 ICC paper on "A tectonically controlled rock cycle", I have a section on "Crystal growth in magmatic fluids" that makes the same point. I quote Luth, W.C. "Granitic rocks", in Bailey and Macdonald (eds), "The evolution of the crystalline rocks", Academic Press, 1976, 333-417. He says: "It is frequently assumed that the presence of large crystals in these phases implies slow growth over long periods of time. Although this may be the case, the intent here is to demonstrate that it does not necessarily hold" (p.405). This is exactly the point I have been making, and I see the "Geology" paper last year as yet another confirmation of this same basic point.

I hope you were closer to what the other paper says than you are to this one - because afaics you are so far off base here it's hard to credit. No coarse crystals grew from this melt, even though they were careful to note that seed crystal to promote nucleation were present.

Here's an exercise you might like to work through :wink:

http://www.chemsoc.org/networks/learnnet/jesei/cooling/home.htm

[rach12]

It produced "fine- to medium-grained holocrystalline rock". All that holocrystalline means is that the rock is wholly crystalline with no glass.
yes, as geochron asks, please quote the sentence where Gibb states the study resulted in "fine to medium-grained holocrystalline rock." I agree with the "fine" but from what I saw in Figure 5, those crystals are definitely nowhere near being medium-grained.

And Dave, I do know what holocrystalline means.:smile:


Crystallisation rates are a matter of physics and chemistry - they *have* to be relevant to naturally ocurring "plutons".
Of course chemistry and physics are relevant to crystallization rates, I just don't think this study necessarily is. The conditions are just too far removed from the natural setting of granitic plutons.


I understand the point you are trying to make. I do think it's possible that granite can crystallize much faster than previously thought, I just don't think this study supports that hypothesis.

[Monkey Boy]

I quote Luth, W.C. "Granitic rocks", in Bailey and Macdonald (eds), "The evolution of the crystalline rocks", Academic Press, 1976, 333-417. He says: "It is frequently assumed that the presence of large crystals in these phases implies slow growth over long periods of time. Although this may be the case, the intent here is to demonstrate that it does not necessarily hold" (p.405).

Stop the presses! There are exceptions to the rule! The question is, are there ways to test when the rule likely holds and when it doesn't?

This is exactly the point I have been making, and I see the "Geology" paper last year as yet another confirmation of this same basic point.

If your point is that grain size is not always indicative of long timescales, then I doubt you'd receive much argument from anyone here. My point is that the "Geology" paper describes conditions so far removed from natural settings that to cite it as evidence against the slow formation of large crystals is misleading.

[aniso]

David, do the words 'annealed', 'recrystallized', 'fractures' or 'partial melt' mean anything to you? I'm sorry to pile on here, but you present a target rich environement that I cannot resist.

The paper declares two issues that the authors wanted to explore: “First, sufficient melting ....

What? 'Sufficient melting?' Why not complete melting? Does this mean that you don't really start with a magma?

Now, can you tell us why this is different from a natural granite pluton?

...of the granite will occur ...

Do you think that a partial melt of a granite will give you a granitic magma? Do you think the volatile content of the partial melt is the same as the actual granite parent?

... at low enough temperatures for the containers to survive, and second, the partial melt to be completely recrystallized to a fine- to medium-grained holo-crystalline rock – both on timescales appropriate to the thermal decay of the waste." Both are important for the proposed waste disposal method to work. Rather than barely touching on grain size, the paper reports experimental data to show that the second requirement is confirmed.

This comment is a mystery to me. The authors wrote their paper because they had some significant conclusions - and the conclusion on crystallisation is the one I've been citing.

Now, if they said that all granite plutons cooled from 800 to ambient temperatures in less than a year, THAT would be significant. Why didn't they?

It produced "fine- to medium-grained holocrystalline rock". All that holocrystalline means is that the rock is wholly crystalline with no glass.

Of course it did! There were medium grained crystals there from the beginning!

Crystallisation rates are a matter of physics and chemistry - they *have* to be relevant to naturally ocurring "plutons".

Indeed, and part of that is that some of these granite plutons are thousands of cubic miles in size. Was this duplicated in the lab?

If you believe granites are emplaced as large plutons, it would be expected that cooling would be slow.

Do you believe this?

The point I was picking up was that information re long cooling times can be extracted from the granitic texture. This is where the paper I cited is relevant. The belief in long cooling times is model dependent, and does not emerge from the physics of granite crystallisation.

Of course not. As we have said repeatedly, granitic textures are not a simple case of cooling rate. Why have you ignored us?

There are numerous other papers - this just happened to be a convenient example. Acanthostega has helpfully posted references to several others.

Then lets discuss them. What do they say?

In my 1990 ICC paper on "A tectonically controlled rock cycle", I have a section on "Crystal growth in magmatic fluids" that makes the same point. I quote Luth, W.C. "Granitic rocks", in Bailey and Macdonald (eds), "The evolution of the crystalline rocks", Academic Press, 1976, 333-417. He says: "It is frequently assumed that the presence of large crystals in these phases implies slow growth over long periods of time. Although this may be the case, the intent here is to demonstrate that it does not necessarily hold" (p.405).

Good, then he agrees with us. Long times are not necessary for SOME crystals to form. However, when taken with other data, it is likely that large plutons cooled over a long period of time.

This is exactly the point I have been making, and I see the "Geology" paper last year as yet another confirmation of this same basic point.

I don't think so, David. I think your point is that the earth is young because sometimes magmatic crystals formed rapidly.

Clearly, David, your presupposition of a young earth has driven you to misinterpret the literature on this. It has forced you to ignore words like 'REcrystallization' and 'annealing' and 'metamorphic haloes'. It has resulted in the unlikely presence of fractures in a magma and partial melts of a granite that have the same composition as granite.

[HiddenOne]

It seems to me that this discussion is a bit off kilter. D Tyler asserts that crystal size is not necessarily indicative of slow cooling but then takes it to the extreme by concluding that because it is not always slow cooling, it must mean only fast cooling. In fact, it appears as if D tyler would assert that the cooling is always fast. This is a leap and in fact is not supported by observational data. Cooling rates in plutons have been measured via radiometric dating and do not fit the ye model. Simple (and so far as I know non-controversial) thermodynamics can give us an estimate for simple conductive cooling models of things like dykes and sills. D tyler's only answer would be that nothing large ever cools conductively since they would negate the ye-model (eg things like the Palisades sill). In short, I don't see much of an argument here. Both sides agree that large crystal size is not indicative of slow cooling in every case, but no case has been cogently argued that large crystal size ALWAYS reflects fast cooling in a flood model. D tyler, you've got some work to do.

[aniso]

It seems to me that this discussion is a bit off kilter. D Tyler asserts that crystal size is not necessarily indicative of slow cooling but then takes it to the extreme by concluding that because it is not always slow cooling, it must mean only fast cooling. In fact, it appears as if D tyler would assert that the cooling is always fast.

Indeed. As with many discussions here, we are talking past each other. However, if David's point is NOT that all plutons cooled rapidly and hence they are not evidence of an old earth, then just what is the point? I seriously doubt that a YEC brings up such simple, interesting facts on a discussion board such as this without some motive beyond elightenment.

This is a leap and in fact is not supported by observational data. Cooling rates in plutons have been measured via radiometric dating and do not fit the ye model. Simple (and so far as I know non-controversial) thermodynamics can give us an estimate for simple conductive cooling models of things like dykes and sills. D tyler's only answer would be that nothing large ever cools conductively since they would negate the ye-model (eg things like the Palisades sill). In short, I don't see much of an argument here. Both sides agree that large crystal size is not indicative of slow cooling in every case, but no case has been cogently argued that large crystal size ALWAYS reflects fast cooling in a flood model. D tyler, you've got some work to do.

It is possible that David's only objective was to counter the 'macrocrystals equals slow crystallization' argument but the point is a very narrow and simplistic argument with limited applicability to the geological record.

[dtyler]

In view of the many posts all directed at me, I shall attempt a general response. Please bear in mind that the topic originated from a remark by Monkey Boy suggesting that coarse grain size implies long timescales. I have not been advancing arguments for a young earth on this occasion - I have focused on the specific issue of: does a coarse grain size imply long timescales? This means that numerous comments have been made that do not address this particular exchange. I do not think it appropriate to answer such comments - because it diverts attention from the point at issue.

I have claimed not only that the "Geology" paper demonstrates relatively rapid crystallisation (timescales of the order of 1 year), I have also quoted the authors as saying that the timescales are much shorter than many geologists would expect. "... completely recrystallized on a timescale of years as opposed to millenia as widely believed". Not only do I think the paper is a relevant one to direct Monkey Boy's attention to because of the experimental findings, it is also directly relevant to his original comment that stimulated this exchange. Significantly, *none* of those questioning my judgment on this paper have attempted to explain the "true meaning" of the authors' comments.

It has een difficult to find anything new to add - but here are a few additional thoughts.

The authors write:
"Crucially, in the context of the [waste disposal] schemes, little or nothing is known about how rapidly granitic magma can be cooled and still give rise to a holocrystalline rock. Similarly, there are no directly determined data for the minimum times needed for the crystallisation of medium- and coarse-grained granites." (They make the point that cooling rates of granitic bodies have been deduced from simulated cooling times to be millenia long). "These have encouraged a widely held belief that granites can only form by extremely slow crystallisation over thousands, if not millions, of years. There are, however, good grounds for believing that silicic magmas can be completely crystallized at cooling rates orders of magnitudes faster".
It is worth noting that the authors use "fine", "medium" and "coarse" grain sizes in their paper. the results are generic - they apply to granitic textures per se. Those who have commented on this aspect of the paper appear to have missed this point.

Also, there have also been comments about the words 'annealed', 'recrystallized', 'fractures' or 'partial melt' - as if these differences between the waste storage model and the natural emplacement of granites weakens the point I am making. It does not weaken them, because my comments relate to the physics and chemistry of the system - and that is common ground between the context of the paper and the natural system.

The paper reports >50% melting prior to recrystallisation. This may not be far from the natural system, as nucleation and the development of phenocrysts in magmatic fluids would be expected. The main difference relates to equilirium conditions in the natural system and non-equilirium conditions in the natural system. This is, as I see it, the only basis on which anyone can legitimately criticise my use of this paper. My defense is that the differences appear to be minor.

I have had a look to see if the research has received comment elsewhere. there was a significant write-up in Nature Science Update:
"Nuclear waste could bury itself. Geologists calculate melted granite would contain high-level waste." TOM CLARKE, Nature Science Update, 13 August 2003. http://www.nature.com/nsu/030811/030811-4.html
Here is a quote:
"Geologists had doubted that granite would return to its ultra-durable state if it cooled too quickly - most granite formed after cooling for hundreds of thousands of years. Gibb and colleague Philip Attrill showed in the lab that melted granite returns to its original form within weeks at pressures similar to those at a depth of 5 km."
An illustration has this caption: "Melted granite returns to its original form within weeks."
Another comment from another source:
"Of particular interest is his lab work showing that molten granite would recrystalize in a matter of weeks instead of hundreds of thousands of years as previously thought."
http://www.sciscoop.com/story/2003/8/19/7633/86479

These quotes show exactly the same attitude to the work to my own. This work in the lab does have a bearing on natural systems and details re "fine", "medium" and "coarse" grained fabrics are out of place. The disposal model needs to demonstrate that the granitic texture is restored, so the capsule containing waste is encased with granite that is essentially the same as the country rock. This is what the authors claim they have done.

I will conclude by addressing the most recent post:
It seems to me that this discussion is a bit off kilter. D Tyler asserts that crystal size is not necessarily indicative of slow cooling but then takes it to the extreme by concluding that because it is not always slow cooling, it must mean only fast cooling. In fact, it appears as if D tyler would assert that the cooling is always fast. This is a leap and in fact is not supported by observational data.
You are putting words in my mouth here. Where have I said that cooling is always fast? My objective has been to challenge the assumption that granitic textures mean long timescales - and I have not attempted to take the discussion eyond that. Once the point is accepted, I am willing to discuss these timescale issues.

[grmorton]

You are putting words in my mouth here. Where have I said that cooling is always fast? My objective has been to challenge the assumption that granitic textures mean long timescales - and I have not attempted to take the discussion eyond that. Once the point is accepted, I am willing to discuss these timescale issues.

While you haven't said those words (your narrow focus), everytime batholiths come up you argue for rapid cooling. I have yet to see you ever argue for slow cooling. Can you point to one place where you have argued for slow cooling? If you can't, then one can only conclude that all you are interested in is rapid cooling to fit into your 'old-earth' (8000 years as opposed to 6000 years) viewpoint. (see http://www.theologyweb.com/forum/showthread.php?p=352542&highlight=8000#post352542)

So, you don't need to say it. Actions speak louder than words anyway. And your view of the earth as only being 8000 years belies the disingenuous point you haven't said that coolling must be rapid. Your viewpoint absolutely requires it, yet you don't tell the truth in your statement above. Look at these cases for places you have argued for rapid cooling.


http://www.theologyweb.com/forum/showthread.php?p=410033&highlight=cooling#post410033

http://www.theologyweb.com/forum/showthread.php?p=374145&highlight=cooling#post374145

http://www.theologyweb.com/forum/showthread.php?p=317609&highlight=cooling#post317609

http://www.theologyweb.com/forum/showthread.php?p=466856&highlight=cooling#post466856

I simply don't understand why you don't simply stand up honestly and acknowledge that your view does require rapid cooling by anyone's viewpoint.

[aniso]

You are putting words in my mouth here. Where have I said that cooling is always fast? My objective has been to challenge the assumption that granitic textures mean long timescales - and I have not attempted to take the discussion eyond that. Once the point is accepted, I am willing to discuss these timescale issues.

Very well, David, based on you word, I will allow that you are not trying to suggest that all granites formed instantaneously in a geological sense.

However, I still have issues, perhaps with the authors, about what they mean by recrystallization and crystallization versus crystal growth. I also, have a problem with saying that the products of these experiments are actually rocks. In the strictest definition, they are not. They are synthetic materials. To me a granite is a naturally occurring substance.

Further, I have issues with the fact that the material they started off with is not a magma which is considered the normal precursor to a pluton. It is granite, already solidified. (In fact, it is a granite core sample, and can hardly be considered equivalent to a naturally occurring pluton.) It hardly surprises me that if you take a granite and partially melt it and then cool it, that you would have some macrocrystals. It would be just as logical to assume that they might have been there all the time. If this is not the case, it is not clear from the discussion.

Further, it seems to me that this process has produced textures that are different and observable in the new granite that are not abundant in nature.

Some how, I seriously doubt the direct applicability of this experiement to the natural world and also that Monkey Boy was discussing laboratory metamorphic reactions in his original statement about coarse grain sizes and slow cooling.

I will accept your statement that you are only pointing out that granitic material can recrystallize relatively quickly under laboratory conditions. I reject the notion that this applies to large scale plutonic processes, unless you can provide more data. There are simply too many variables here that you do not address. I suggest that the scope of these studies was not inclusive of petrology, but more focussed on the practical aspects of waste storage.

[geochron]

I'm sorry, the paper has no implications whatsoever for your point about coarse grain size not implying slow cooling. Allow me to edit your own post to point out how confused you are becoming...


Please bear in mind that the topic originated from a remark by Monkey Boy suggesting that coarse grain size implies long timescales.

[...]

I have focused on the specific issue of: does a coarse grain size imply long timescales?

[...]

These quotes show exactly the same attitude to the work to my own. This work in the lab does have a bearing on natural systems and details re "fine", "medium" and "coarse" grained fabrics are out of place.



But details about fine, medium and coarse grained fabrics are exactly what you start out saying you are addressing.

I'll take this little bit out of sequence..


It is worth noting that the authors use "fine", "medium" and "coarse" grain sizes in their paper. the results are generic - they apply to granitic textures per se. Those who have commented on this aspect of the paper appear to have missed this point.


Nope, they don't.

The results are not generic when generic means applying across all grain sizes since they don't show that a coarse grain size can be formed in a short time. They do show that a granite melt can recrystallise on a relatively short timescale. Did you look up rhyolite yet?

The one who has missed a point here is you. And all your selective quoting won't make that go away. The paper doesn't support your point, and the longer you deny it the lower your credibility falls. You're wrong, but either can't see it or won't admit it.

[Kulindrichnus]

This is a very curious thread. Thus far I have stayed out of it, because I am not a polymath, and as a sedimentologist, igneous petrology is far from my field of knowledge. I would like to make a few points, some of which are summations of the views of others, some of which are my own. If they are erroneous it is a function of lack of experience in this area and I offer that as a pre-emptive absolution.

I am at home and thus don't have journal access so have not read the 'Geology paper' . I have, however, read the Sheffield abstract (http://www.shef.ac.uk/isl/abstracts/abs2003.html#anchor23) of Gibb's work.

1. The only involvement granite has in Gibbs' work is as a parent material, a solid-phase silicate from which he generates a silicic, water-rich partial melt.

2. A partial melt is composed only of those mineral phases which melt at or below a particular temperature, and is by definition depleted in those phases which melt at a temperature above. In Gibb's experiments the melt also includes additional volatiles (water) introduced by Gibb, rather than derived from the parent granite. It is inappropriate to describe the liquid-phase of Gibbs' experiments as a granite magma, because a) as a partial melt the magma is artificially depleted in those phases which crystallise at very high temperatures, and b) is artificially enriched in volatiles. I note that Gibb calls it 'silica rich magma', not a granite magma.

3. The composition of a melt determines the temperatures at which crystals form, and the sequence in which they crystallize (melt fractionation). This is important because the temperature intervals between the crystallization of each mineral phase control the time available for crystal growth, and the time available for crystal growth controls the coarsness of final the solidified rock.

4. Geochemically, Gibb's partial melt magma lacks those phases which would crystallize at the highest temperatures and thus have the opportunity to grow in the absence of the competitive crystallization of other phases. It will not fractionate as a granite melt, and will not follow the geochemical pathway of a granite melt during cooling.

5. Physically, Gibb's partial melt magma is admixed (as a partial melt must be) with solid-phase crystals. This is important, becase such crystals a) define the minimum crystal size of the cooled partial melt (because they were never melted in the first place) and b) provide sites of nucleation for the crystallizing liquid phase, which would not be present in a complete melt. Importantly, with respect to those minerals present within the liquid phase, these crystals are disproportinately composed of the highest-melting point ones, because the solid-phase component of the lower melting-point liquid phase minerals would be expected to have been proportionately more consumed during heating. Such crystals allow energy loss from the liquid phase via overgrowth crystallization, and a partial melt will therefore cool more quickly than a complete melt. Gibb's melt will not follow the physical crystallization pathway of a granite melt when cooling.

6. Finally, there are heatflow considerations picked up by others: firstly, that the maximum temperature of the partial melt (and thus its' geochemistry) is controlled by Gibb. The temperatures are, by definition, considerably lower than those of a natural granitic complete melt. Secondly, the cooling rate, also controlled by Gibb, is artificially high. I would add that Gibb is only able to generate artificially high cooling rates because he is working with very small volumes of material. A crucible of melt has a more favourable surface area: volume ratio than a batholith. Thus a natural melt will, by virtue of its' physical dimensions, cool more slowly and take a different crystallization pathway.

David argues that this work supports two assertions; firstly, that a granitic magma can cool to solid magma quickly; and secondly, that large crystals can be grown in a rapidly cooling melt.

1) this is essentially the same argument, because in the first instance David is talking about a granite purely as a coarse-grained rock, not as a entity with a distinct geochemistry.

2) Gibb's melt is not a geochemical granite. It lacks those mineral phases which crystallize both first and longest. It contains only the lower melting-point phases which might be expected to crystallize successively more rapidly after each other. It would be expected to crystallize quickly once a critical temperature had been reached.

3) Gibb's melt is not physically a complete magma but a partial melt. It already contains grains of a certain crystal size which never participated in the liquid phase of the partial melt. No matter how rapidly it crystallizes it's minimum crystal size will be controlled by these crystals.

4) A cooling history would be as follows. Once the melting point of the highest melting point minerals within the liquid phase of the melt is reached, they will begin to crystallize on the abundant sites for nucleation present as a consequence of the of pre-extant solid-phase crystals. This results in a rapid crystallization of these minerals (by comparison to a complete melt), promoting the cooling of the partial melt and thus the even more rapid crystallization of a succession of lower melting-point phases.

It is not suprising that such a melt crystallizes rapidly, especially if artificially cooled. The resultant texture would be abundant coarse crystals of the highest melting-point mineral phases set in a groundmass of competitively-grown low melting-point ones (as Geochron says, something like a rhyolite not a granite). Note however that the largest crystals are still the highest melting point ones, and the relationship between crystal size and relative time for crystallization, between the mineral phases, is intact.

Why is this not analagous to a granite batholith?

1. This was not geochemically a granite melt. A batholith is. By dint of the presence of higher melting point minerals in the liquid phase of a true granite magma, it must take longer to cool than a melt depleted in them.

2. A granite melt does not contain crystals which both dictate a minimum grainsize, speed crystallization, and increase the rate of cooling. All three of those are very conveninent (are the crux of) dave's argument. However in a true granite melt, a lengthy period is required for crystal nucleation, and the cooling and speed of solidification will depend on the rate at which those first crystals grow, not on the presence of surplus sites for crystallization.

3. A batholith has significantly higher heat flow and retarded heat loss due to its' physical proportions in comparison to a lab experiment.

Gibb's melt crystallized quickly because of its chemical composition and is coarse because of its physical constitution. Granites have a chemistry which demands a longer period of crystallization and a lack a physical constitution which promotes rapid crystallization. Batholiths have retarded geat flow capabilities, kilo for kilo, in comparison to lab experiments.

K

[SteveF]

To be honest I just don't see the point of the post given that David says there are no ulterior creationist motives.

To summarise; David is saying that some processes happen relatively quickly, or maybe not as slowly as prreviously thought. We all know this, I could post on palaeoclimate changes that were rapid, but I won't bother as there isn't really a point.

[grmorton]

To be honest I just don't see the point of the post given that David says there are no ulterior creationist motives.

If you believe that, I got a bridge to sell you. :deal:

[grmorton]

Hardly. A "track" is a term reserved for things with legs. You have posted a "trail". If you had asked me, "what were animals doing making trails in the Cambrian and Ordovician?", I would have answered - participating in the recolonisation of the Earth after the Mabbul destruction. You need not post Ordovician trails - I have them in my own collection.

David, I ran across an article in Nature today--in an issue I apparently never got. It reports tracks in the Cambrian. It is:

http://www.nature.com/nature/journal/v417/n6885/images/417129a-i1.0.jpg (http://www.nature.com/nature/journal/v417/n6885/images/417129a-i1.0.jpg)

The article is Tom Clarke, "Geology: A foot in the past,"
Nature 417, 129 (09 May 2002);

I don't know if the picture will show up because of Nature's security system. It shows up on my screen but I subscribe to Nature.

But the article says:
"The oldest fossils of footprints ever found on land suggest that animals may have emerged from the seas much earlier than had been thought. Lobster-sized, centipede-like animals made the prints shown here about 500 million years ago. Previous fossils had indicated that animals took this step around 40 million years later."

The interesting thing is, that even if you discount this fossil, the earliest land tracks are from the Ordovician 460 myr ago. So, your flood still has animals walking around on land, David.

The original report is MacNaughton et al, Geology 30(2002):391-394.

[aniso]

Originally Posted by Steve Forden

To be honest I just don't see the point of the post given that David says there are no ulterior creationist motives.

If you believe that, I got a bridge to sell you. :deal:

Yeah, well, it is a bit of a stretch isn't it? I suppose it could be considered offering David a face-saving way out of his predicament on this thread. Would we want to do that?

Nah.

Any how, I see some obvious backpedaling here by David to avoid well-founded critcism for his oveall viewpoint. He knows that he cannot defend his YE views so he attempts to avoid the brunt of it by limiting his objectives to a special case.

[grmorton]

Yeah, well, it is a bit of a stretch isn't it? I suppose it could be considered offering David a face-saving way out of his predicament on this thread. Would we want to do that?

Nah.

Any how, I see some obvious backpedaling here by David to avoid well-founded critcism for his oveall viewpoint. He knows that he cannot defend his YE views so he attempts to avoid the brunt of it by limiting his objectives to a special case.

I have known David now for about 20+ years. I have watched him do this limited objective dance, with total compartmentalization and no consideration for other areas, for about that long. It is the total compartmentalization which is so problematic for YECs. They solve a problem A by ignoring problems B, C, D, E,....
Then they solve problem B by ignoring problems A, C, D, E....

and so forth.

David claims he isn't after rapid cooling and seems genuinely surprised that anyone would think that of him. But then he believes in an 8,000 year old earth and doesn't consider himself a YEC because he doesn't believe in a 6000 year old universe--its called intellectual compartmentalization.

[Fedmahn Kassad]

Yes. The Earth was being destroyed and all air-breathing creatures were wiped out - saving only those on the ark.

Are you suggesting that blue whales were carried on the Ark?

FK

[Kulindrichnus]

I have known David now for about 20+ years.

Why!!??

David claims he isn't after rapid cooling and seems genuinely surprised that anyone would think that of him. But then he believes in an 8,000 year old earth and doesn't consider himself a YEC because he doesn't believe in a 6000 year old universe--its called intellectual compartmentalization.

It's called a bunch of beliefs, has nothing to do with reality or the exploration of it (i.e., science), and shows David up for what he is- a fraud and a sham.

K

[grmorton]

Why!!??

Why have I known David for 20+ years? Because I was a publishing YEC who wrote 30 articles on the topic. I got to know lots of other YECs, David included.

[Kulindrichnus]

Why have I known David for 20+ years? Because I was a publishing YEC who wrote 30 articles on the topic. I got to know lots of other YECs, David included.

Yes, I know that... it was rhetorical exasperation at the idea that David has been arguing like this for so long, rather than a genuine question. I should've made it more clear...

K

[geochron]

Are you suggesting that blue whales were carried on the Ark?

FK

I guess so - they would have had trouble breathing through that thick layer of matted vegetation...

[SteveF]

Just to add a little to the Archean debate, we have the following abstract (can't get full text with our uni subscription) just published on science (express):

- Arnold et al (2004) Molybdenum Isotope Evidence for Widespread Anoxia in Mid-Proterozoic Oceans.

- How much dissolved O2 was present in the mid-Proterozoic oceans between 1.8 and 1.0 billion years ago is debated vigorously. One model argues for oxygenation of the oceans soon after the initial rise of atmospheric O2 ~ 2.3 billion years ago. Recent evidence for H2S in some mid-Proterozoic marine basins suggests, however, that the deep ocean remained anoxic until much later. New Mo isotope data from modern and ancient sediments indicate expanded anoxia during the mid-Proterozoic compared to the present day ocean. Consequently, oxygenation of the deep oceans may have lagged the atmopshere by over a billion years.

So this reseach suggests that the Archean had lower atmospheric oxygen levels, obviously bad news for Noah who according to david was floating around at that time. Furthermore, as the Archean ended around 2.5 billion years ago, atmospheric oxygen was still low during the early stages of recolonisation. How did those animals cope? Furthermore how did marine animals cope during the low oceanic oxygen days of the flood?

[dtyler]

While you haven't said those words (your narrow focus), everytime batholiths come up you argue for rapid cooling. I have yet to see you ever argue for slow cooling. Can you point to one place where you have argued for slow cooling? [...] I simply don't understand why you don't simply stand up honestly and acknowledge that your view does require rapid cooling by anyone's viewpoint.
I have never disguised the fact that rapid cooling is part of my understanding of the geological past. My point is that rapid cooling is not the issue in this exchange. I have explained several times that the stimulus for the exchange came from the expressed view that coarse crystalline textures of igneous rocks are an indication of long timescales. That is an issue that is worth exploring in a narrowly focused way - because the issue can be clarified and it does not depend on whether you are a young earth or an old earth advocate.

I have persisted with the exchange only because my use of a recent paper was deemed unacceptable - an abuse of the literature. My conviction is that there has been no abuse. If the discussion moves to where I am defending the rapid cooling of large granitic bodies, then I would not make use of the paper in "Geology" to support that. I greatly fear that those who have been objecting to my understanding of the paper are objecting to what they *think* I am saying rather than to what I am *actually* saying.

[DunnySaze]

If the discussion moves to where I am defending the rapid cooling of large granitic bodies, then I would not make use of the paper in "Geology" to support that.

I'm curious. What paper(s) then would you use to defend the rapid cooling of large granitic bodies?

[dtyler]

Very well, David, based on you word, I will allow that you are not trying to suggest that all granites formed instantaneously in a geological sense.
No, this exchange has been about crystallisation rates, not about models of emplacement and cooling rates.

However, I still have issues, perhaps with the authors, about what they mean by recrystallization and crystallization versus crystal growth. I also, have a problem with saying that the products of these experiments are actually rocks. In the strictest definition, they are not. They are synthetic materials. To me a granite is a naturally occurring substance.

All experimental petrology has to work with these issues. Magmas are extraordinarily complex fluids - especially when pressure changes are introduced. In your strict definition, no one has done anything experimentally with anything other than synthetic materials! I happen to think that Gibb and Attrill are closer to the natural case than most past experimenters.

Further, I have issues with the fact that the material they started off with is not a magma which is considered the normal precursor to a pluton. It is granite, already solidified. (In fact, it is a granite core sample, and can hardly be considered equivalent to a naturally occurring pluton.) It hardly surprises me that if you take a granite and partially melt it and then cool it, that you would have some macrocrystals. It would be just as logical to assume that they might have been there all the time. If this is not the case, it is not clear from the discussion.
The issue of non-equilibrium melting is one I have already flagged up. It is an issue that I would not want to overlook. However, phenocrysts must form in magmatic fluids, and sometimes before emplacement. Since ultimately we are dealing with the physics and chemistry of magmas, the experimentally determined rates of processes can still be applied to the natural case.

Further, it seems to me that this process has produced textures that are different and observable in the new granite that are not abundant in nature.
If that were so, there is a fundamental flaw in the conclusions reached by the authors.

Some how, I seriously doubt the direct applicability of this experiement to the natural world and also that Monkey Boy was discussing laboratory metamorphic reactions in his original statement about coarse grain sizes and slow cooling.
In which case, you would need to doubt the relevance of most experimental petrology to the natural world. I do not recall Monkey Boy "discussing laboratory metamorphic reactions in his original statement about coarse grain sizes and slow cooling" - but if he had, this could be followed up.

I will accept your statement that you are only pointing out that granitic material can recrystallize relatively quickly under laboratory conditions. I reject the notion that this applies to large scale plutonic processes, unless you can provide more data. There are simply too many variables here that you do not address. I suggest that the scope of these studies was not inclusive of petrology, but more focussed on the practical aspects of waste storage.
My argument is based on the physicas and chemistry of magmatic fluids. The distinction you are making between laboratory conditions and the natural world is contrived - the experiments are done to help us interpret data in natural systems. Furthermore, I can now report that the authors of the original paper see their results to be "of considerable relevance" to natural systems.
They have published a full account of their experimental work on recrystallisation here:
Partial melting and recrystallization of granite and their application to deep disposal of radioactive waste. Part 2––Recrystallization.
P. G. Attrill and F. G. F. Gibb
Lithos, Volume 67, Issues 1-2 , March 2003, Pages 119-133.

This is from the Conclusion: "While the experiments reported in this paper were undertaken primarily in connection with radioactive waste disposal schemes, it should not be overlooked that the results are also of considerable relevance for the natural crystallization of acid magmas. This applies particularly to the interpretation of textures and grain sizes in obsidians, pitchstones and fine- to medium-grained, crystalline, felsic rocks."

I think readers of these exchanges should read again the complaints about quote mining and misuse of the literature with the above comment impressed on their minds.

[rach12]

Further, it seems to me that this process has produced textures that are different and observable in the new granite that are not abundant in nature.

If that were so, there is a fundamental flaw in the conclusions reached by the authors.
How so?

Nowhere in the Conclusion do the authors state anything about crystal size or texture. They only conclude that sufficient partial melting occurred and that the granite was able to recrystallize quickly, which is a requirement for deep borehole waste disposal, and therefore, granites make suitable hosts for waste disposal.

What do you think the conclusions stated?



Monkey initially stated:

As just one example, the speed of cooling of an igneous formation can be roughly gauged by looking at the size of the crystals in the rock. The larger the crystals, the slower the cooling.

You followed with:

For years, this was used as an argument for vast ages for granite crystalisation. Then laboratory studies started to show that the ages might not be so long. A recent study says that the time scale can be "years as opposed to millenia".

Granite recrystallization: The key to the nuclear waste problem?, Fergus G.F. Gibb and Philip G. Attrill, Geology: Vol. 31, No. 8, pp. 657–660.
ABSTRACT: We report the outcome of high-temperature, high-pressure experiments showing that granite can be partially melted and completely recrystallized on a time scale of years as opposed to millennia as widely believed. ...

Dave, you are using this paper as an argument against coarse grain size implying long cooling times for granite, however, as has been pointed out, neither medium or coarse grain sizes were produced by the study. Gibb and Attrill were only able to produce fine grain sizes (aphanitic) with textures that are not typically found in granite (judging from Figure 5). You have not proven your point with this paper and so Monkey's point about course grain sizes is still valid.

When Gibb and other workers manage to produce textures and grain sizes that actually resemble natural granite, then I think they have truly acheived something. At this moment, the findings are interesting - that's it.



Some how, I seriously doubt the direct applicability of this experiement to the natural world and also that Monkey Boy was discussing laboratory metamorphic reactions in his original statement about coarse grain sizes and slow cooling.

In which case, you would need to doubt the relevance of most experimental petrology to the natural world.
We should doubt it. The theoretical aspects of geology are interesting and often exciting; however, they are not necessarily applicable to a real-world setting. Much more research needs to be done before the rest of the geologic community is convinced granite plutons can cool in a few hundred or a couple thousand years.



My argument is based on the physicas and chemistry of magmatic fluids. The distinction you are making between laboratory conditions and the natural world is contrived - the experiments are done to help us interpret data in natural systems.
Contrived? There is a HUGE difference between a controlled laboratory environment and the natural world. Lab work is like uniformitarianism - they help us gain a better understanding of the natural system, but that doesn't mean they give us perfect analogs.

And Dave, let's be honest here, your argument is based on you not wanting to equate large crystal size with long cooling times because it doesn't fit your young earth hypothesis. If your argument was based on physics and chemistry of magmatic fluids, we'd be reading a lot more on thermodynamics, fluid dynamics, magma chamber evolution, nucleation rate and oxygen fugacity rate fluctuations, crystal growth in thermal gradients, ... none of which are even discussed in the Gibb and Attrill paper.

[dtyler]

Nowhere in the Conclusion do the authors state anything about crystal size or texture. They only conclude that sufficient partial melting occurred and that the granite was able to recrystallize quickly, which is a requirement for deep borehole waste disposal, and therefore, granites make suitable hosts for waste disposal.
What do you think the conclusions stated?
That the granitic texture of the original granite was restored after the partial melting, resulting in a strong and robust casing around the waste.

Dave, you are using this paper as an argument against coarse grain size implying long cooling times for granite, however, as has been pointed out, neither medium or coarse grain sizes were produced by the study. Gibb and Attrill were only able to produce fine grain sizes (aphanitic) with textures that are not typically found in granite (judging from Figure 5). You have not proven your point with this paper and so Monkey's point about course grain sizes is still valid.
Monkey did not say "coarse" - I did. Gibb and Attrill repeatedly refer to fine- to medium-grained granite. Since the findings relate to physics and chemistry of magmas, I deduce the same principles apply to coarse grained materials.

When Gibb and other workers manage to produce textures and grain sizes that actually resemble natural granite, then I think they have truly acheived something. At this moment, the findings are interesting - that's it.
This seems a very grudging comment. Very few crystallization studies have made use of multiple component magmas and even fewer on natural granite. Gibb and Attrill have not just done interesting ork, they have significantly advanced our knowledge of the crystallization of multiple component magmas.

We should doubt it. The theoretical aspects of geology are interesting and often exciting; however, they are not necessarily applicable to a real-world setting. Much more research needs to be done before the rest of the geologic community is convinced granite plutons can cool in a few hundred or a couple thousand years.
You are confusing two issues. We are here discussing crystallization rates, not the cooling of granite plutons.

Contrived? There is a HUGE difference between a controlled laboratory environment and the natural world. Lab work is like uniformitarianism - they help us gain a better understanding of the natural system, but that doesn't mean they give us perfect analogs.
This sort of comment appears to me to minimise the importance of a great deal of empirical work. There are differences, but with intelligent design of experiments, they can relate well to certain aspects of the natural system.

And Dave, let's be honest here, your argument is based on you not wanting to equate large crystal size with long cooling times because it doesn't fit your young earth hypothesis. If your argument was based on physics and chemistry of magmatic fluids, we'd be reading a lot more on thermodynamics, fluid dynamics, magma chamber evolution, nucleation rate and oxygen fugacity rate fluctuations, crystal growth in thermal gradients, ... none of which are even discussed in the Gibb and Attrill paper.

Let's be honest. I find it very frustrating when good scientific arguments are rubbished because of a red herring thrown in to muddy the waters. I find it difficult to take opposing arguments seriously when people appear to be more interested in winning than in finding the truth. I have made many comments on the grip "uniformitarianism" has on certain contributors to TheologyWeb - and am repeatedly told that I am fighting a battle that has long been resolved. This is a specific case: the belief that granitic textures implies deep time. It is a relic of uniformitarianism. I chose to focus on that issue and show that empirical studies have never supported that idea - yet it lingers on. I selected a recent paper that not only documents rapid recrystallisation of a partial melt, but also says the findings may be of surprise to geologists who associate much longer timescales with this process. Instead of this being a simple issue, the feedback I have received has been an example of how not to debate: claiming I have misused the research, claiming (as you have above) that there are other agendas which make my arguments unsound. I am not impressed.

[SteveF]

I find it difficult to take opposing arguments seriously when people appear to be more interested in winning than in finding the truth.
Only the 'truth' as you see it which, in scientific terms at least, was falsified 150 years ago.

I have made many comments on the grip "uniformitarianism" has on certain contributors to TheologyWeb - and am repeatedly told that I am fighting a battle that has long been resolved.
It has been resolved, geologists do accept variable timescales. This one example does nothing to sway this; all it shows (if accurate) is that in this one case there is debate about the length of cooling.

Instead of this being a simple issue, the feedback I have received has been an example of how not to debate: claiming I have misused the research, claiming (as you have above) that there are other agendas which make my arguments unsound. I am not impressed.
Your other agendas (though they may genuinely not be in evidence here) are so radical that they will of course invite extra suspicion. Its natural and perfectly reasonable given that the position from which you approach your work contradicts utterly the available evidence.

Further to this, its a little difficult to accept your arguments as agenda-less. If you had no agenda why would you frequently post, on rather specific topics, on a theological website. Surely its not just as some paradigm busting truth hero obsessed with getting to the bottom of some rather minor issues tucked away in a science?

[dtyler]

This is a very curious thread.
That's true.

I am at home and thus don't have journal access so have not read the 'Geology paper' . I have, however, read the Sheffield abstract (http://www.shef.ac.uk/isl/abstracts/abs2003.html#anchor23) of Gibb's work.

For those who have not looked at this, it is worth pointing out a couple of comments from Gibb:
"Cooling rates deduced from natural granite bodies have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years but there are grounds for believing that acid (silica-rich) magmas can be completely crystallized at cooling rates orders of magnitude faster. To test this, ..."
Note that Gibb thinks that his research has a bearing on the "widely held belief" about granite crystallization rates.

"The experiments demonstrate that a typical crustal granite can be partially melted to yield substantial amounts of silicate liquid at temperatures below 850 °C in the presence of small amounts of H2O and that these liquids can be completely recrystallized when cooled to temperatures around 550 °C at cooling rates less than 0.1 °C/hour. Such cooling rates are very much faster than those under which natural granite intrusions are widely believed to have formed ..."
Note that Gibb is drawing a parallel between his experiments and the natural system. It is not a misquotation to draw a comparison between the experimental system and the natural system.


In several of the points below, I have no problem with what is stated. I pass over this material.

4. Geochemically, Gibb's partial melt magma lacks those phases which would crystallize at the highest temperatures and thus have the opportunity to grow in the absence of the competitive crystallization of other phases. It will not fractionate as a granite melt, and will not follow the geochemical pathway of a granite melt during cooling.
The problem of non-equilibrium melting and non-equilibrium crystallisation has already been noted by myself. However, whilst it must be flagged up, the main conclusions of Gibb and Attril still apply. They did many experiments, with different amounts of water and different cooling rates. They also worked with a granodiorite. The different water concentrations resulted in different melt concentrations at the start of the experiments (37% - 93% melt) and different finishing conditions at 560 deg C - but the same patterns are present throughout.

5. Physically, Gibb's partial melt magma is admixed (as a partial melt must be) with solid-phase crystals. This is important, becase such crystals a) define the minimum crystal size of the cooled partial melt (because they were never melted in the first place) and b) provide sites of nucleation for the crystallizing liquid phase, which would not be present in a complete melt. Importantly, with respect to those minerals present within the liquid phase, these crystals are disproportinately composed of the highest-melting point ones, because the solid-phase component of the lower melting-point liquid phase minerals would be expected to have been proportionately more consumed during heating. Such crystals allow energy loss from the liquid phase via overgrowth crystallization, and a partial melt will therefore cool more quickly than a complete melt. Gibb's melt will not follow the physical crystallization pathway of a granite melt when cooling.
Depending on the amount of water, the seed crystals were dominated by quartz and feldspar - the high temperature minerals. The rate of melt cooling was subject to external control: 3 different rates were used.

6. Finally, there are heatflow considerations picked up by others: firstly, that the maximum temperature of the partial melt (and thus its' geochemistry) is controlled by Gibb. The temperatures are, by definition, considerably lower than those of a natural granitic complete melt. Secondly, the cooling rate, also controlled by Gibb, is artificially high. I would add that Gibb is only able to generate artificially high cooling rates because he is working with very small volumes of material. A crucible of melt has a more favourable surface area: volume ratio than a batholith. Thus a natural melt will, by virtue of its' physical dimensions, cool more slowly and take a different crystallization pathway.
800 degrees C is not an unrealistic figure for a granitic magma. The temperature of source areas is considered about 950 deg C, and the granite will cool as it rises and is emplaced. Please note that the only conclusion about the cooling rates of natural granites I draw from Gibbs and Attrill is that they provide estimates of minimum rates.

David argues that this work supports two assertions; firstly, that a granitic magma can cool to solid magma quickly; and secondly, that large crystals can be grown in a rapidly cooling melt.
I will own the second "assertion": with the proviso that "large" is a relative term. I would want to refer to granitic textures.

2) Gibb's melt is not a geochemical granite. It lacks those mineral phases which crystallize both first and longest. It contains only the lower melting-point phases which might be expected to crystallize successively more rapidly after each other. It would be expected to crystallize quickly once a critical temperature had been reached.
This is not very coherent. If this is saying that the liquid is a non-equilibrium magma, then OK - we've already agreed that. But in all the experiments, quartz and feldspar crystallise out as well as the other minerals. The key point is that all the crystals *grow*. We are not getting nucleation and the formation of a fine-grained groundmass.

3) Gibb's melt is not physically a complete magma but a partial melt. It already contains grains of a certain crystal size which never participated in the liquid phase of the partial melt. No matter how rapidly it crystallizes it's minimum crystal size will be controlled by these crystals.
This is mistaken. There could be mass nucleation and the formation of a fine-grained groundmass or even glass. This would not meet the needs of waste storage,.

It is not suprising that such a melt crystallizes rapidly, especially if artificially cooled. The resultant texture would be abundant coarse crystals of the highest melting-point mineral phases set in a groundmass of competitively-grown low melting-point ones (as Geochron says, something like a rhyolite not a granite). Note however that the largest crystals are still the highest melting point ones, and the relationship between crystal size and relative time for crystallization, between the mineral phases, is intact.
This is not what the paper reports. We do not have phenocrysts in a rhyolite matrix. With one of the samples, the authors report: "It has the mineralogy and texture of granite and demonstrates that almost complete recrystallisation of the 57% partial melt produced at 800 deg C can occur in just over 3 months of cooling at 0.1 deg C/h." (c.f. Lithos paper).

Gibb's melt crystallized quickly because of its chemical composition and is coarse because of its physical constitution. Granites have a chemistry which demands a longer period of crystallization and a lack a physical constitution which promotes rapid crystallization. Batholiths have retarded heat flow capabilities, kilo for kilo, in comparison to lab experiments.
This is a complete misunderstanding of Gibbs. The same melt can give rise to coarese, medium, fine, very fine, glass textures - to get crystals you need a restriction on nucleation and time to grow. The comment I posted earlier is relevant here - because you are trying to drive a wedge between Gibb's work and the relevance of the findings to natural systems.
"While the experiments reported in this paper were undertaken primarily in connection with radioactive waste disposal schemes, it should not be overlooked that the results are also of considerable relevance for the natural crystallization of acid magmas. This applies particularly to the interpretation of textures and grain sizes in obsidians, pitchstones and fine- to medium-grained, crystalline, felsic rocks." (The concluding para of Attrill and Gibb, Lithos paper, 2003).

[geochron]

Oh Man! I don't believe dtyler is still defending this ludicrous position.


Question: What do you think the conclusions stated?
dtyler: That the granitic texture of the original granite was restored after the partial melting, resulting in a strong and robust casing around the waste.


Comment: It doesn't say this anywhere in the conclusion. They say it recrystallises, they don't say it regains its original texture. That's because, in fact, it doesn't.


dtyler:"Cooling rates deduced from natural granite bodies have encouraged a widely held belief that granites can only form by extremely slow crystallization over thousands, if not millions, of years but there are grounds for believing that acid (silica-rich) magmas can be completely crystallized at cooling rates orders of magnitude faster. To test this, ..."
Note that Gibb thinks that his research has a bearing on the "widely held belief" about granite crystallization rates.


No, read more carefully - you've been making this same kindergarten error for days now. They're talking about the rates at which silicic melts can crystallise. Such melts don't always crystallise to granites - sometimes they crystallise quite quickly to fine grained rocks called rhyolites. It is in fact common knowedge that they can "crystallise orders of magnitude faster than this" - why do you think that assertion is not backed up by a reference?

This paper investigates a specific effect of partially melting a granite and examining what is produced - the data are extremely relevant to the nuclear waste disposal industry. Details such as the effect of water and cooling rate on crystallisation (esp in the Lithos paper) may well be relevant to studies of the crystallisation of natural acid magmas (again, notice they don't say "granites") - but as far as the assertion that acid magmas can crystallise relatively quickly goes this paper tells us nothing much new. It won't carry the load you are trying to put on it, and you wouldn't be trying to make it carry that load if you knew basic igneous petrology.


Gibb and Attrill repeatedly refer to fine- to medium-grained granite.


The word "medium" appears twice in their Geology paper. (I have it online and can search). Neither time does it refer to their results.


"While the experiments reported in this paper were undertaken primarily in connection with radioactive waste disposal schemes, it should not be overlooked that the results are also of considerable relevance for the natural crystallization of acid magmas. This applies particularly to the interpretation of textures and grain sizes in obsidians, pitchstones and fine- to medium-grained, crystalline, felsic rocks." (The concluding para of Attrill and Gibb, Lithos paper, 2003).


Indeed, I recommend people read the Lithos paper to get a sense of what they are talking about. But notice again that they don't say "granites".

And since two can play at partial quoting, I'll leave you with this from their Lithos paper:


Crystal growth rates for the main phases formed during cooling are linearly proportional to total H2O content and decrease from alkali feldspar through biotite to quartz. Recrystallizing the partially melted granite at 0.1 [degree] C/h compared with 1 [degree] C/h increases grain size by a factor of f2.5.


So grain size does depend on cooling rate after all!

[aniso]

For those who have not looked at this, it is worth pointing out a couple of comments from Gibb:

"The experiments demonstrate that a typical crustal granite can be partially melted ...

Why 'partially melted'? Why start with a granite? Seems to me that one should start with a true magma if one were trying to make the point about solidifying magma.

...to yield substantial amounts ...

What is a substantial amount? Why not go for the whole melt? Why leave relict crystals in the melt to skew the results later on?

...of silicate liquid ...

Silicate liquid? Are they saying that it wasn't a magma? Are they saying that it is not of granitic?

... at temperatures below 850 °C in the presence of small amounts of H2O ...

Why small amounts of water? Where did the water come from? How did it influence the melt and how did it influence the crystallization?

...and that these liquids can be completely recrystallized ...

What do they mean by 'recrystallized'? Doesn't this sort of corrupt the whole concept of regenerating granitic textures? Doesn't it add a new layer of textural complexity that should be visible in the rock?

... when cooled to temperatures around 550 °C at cooling rates less than 0.1 °C/hour.

Okay, so if this is applicable to nature, show us where this magnitude of cooling would occur in the core of the Idaho batholith.

Such cooling rates are very much faster than those under which natural granite intrusions are widely believed to have formed ..."
Note that Gibb is drawing a parallel between his experiments and the natural system. It is not a misquotation to draw a comparison between the experimental system and the natural system.

Sorry, but Gibb is reaching here. He's done everything possible to create a controlled laboratory environment and then infers that this is a natural process.

This is not very coherent. If this is saying that the liquid is a non-equilibrium magma, then OK - we've already agreed that. But in all the experiments, quartz and feldspar crystallise out as well as the other minerals. The key point is that all the crystals *grow*. We are not getting nucleation and the formation of a fine-grained groundmass.

Correct. My guess is that you are not getting nucleation. The question is, which crystals grow to be large grains? My guess is that they are the same as the crystals left over after the partial melt. In fact, they are probably augmented.

I am not impressed by your argument, David. No one has said that it is not possible to grow large grains relatively quickly. In fact, as I recall, you were given some examples. The real question is how far can you apply such special cases to the intrusion of large plutons? You have not presented any compelling evidence that this is the case. If this were the case, we would see widespread recrystallization textures in granites composed primarily of quartz and feldspar as overgrowths and fracture fillings along with annealing textures as described by your reference. Indeed, we see such things in local cases, but not in every granite of every age.

As I have said: very well, you have shown that there are mechanisms for rapid crystal growth. Now show us that this has anything to do with the general age-of-the-earth issue. On the other hand, it still makes sense that in the vast majority of cases, large crystals require long contact time with solutions of the right composition to form coarse textures.

It appears to me that, once again, in the YEC tradition, you overgeneralize from a special case to the general; all the while ignoring other lines of inconvenient evidence. A disinterested person would have presented the data and said simply that sometimes large crystals can for quickly. You, on the other hand are obviously not disinterested and carry a heavy agenda that you cannot escape. It is apparent to me that you mean to infer that ALL coarse grains formed quickly. This is simply NOT supported by your information.

[rach12]

In response to aniso's statement:

Further, it seems to me that this process has produced textures that are different and observable in the new granite that are not abundant in nature.

you said

If that were so, there is a fundamental flaw in the conclusions reached by the authors.

Then I said:

Nowhere in the Conclusion do the authors state anything about crystal size or texture. They only conclude that sufficient partial melting occurred and that the granite was able to recrystallize quickly, which is a requirement for deep borehole waste disposal, and therefore, granites make suitable hosts for waste disposal.

What do you think the conclusions stated?


To which you replied:

That the granitic texture of the original granite was restored after the partial melting, resulting in a strong and robust casing around the waste.
Read the conclusions again. The original granite texture was not restored and the authors NEVER claimed such a thing in their paper NOR do they make any mention of grain sizes.


Monkey did not say "coarse" - I did. Gibb and Attrill repeatedly refer to fine- to medium-grained granite. Since the findings relate to physics and chemistry of magmas, I deduce the same principles apply to coarse grained materials.
Gibb and Attrill do not "repeatedly" refer to "fine- to medium-grained granite" - they do so once in the following context:

The scheme depends on two crucial premises. First, sufficient melting of the granite will occur at low enough temperatures for the containers to survive, and second, the partial melt can be completely recrystallized to a fine- to medium-grained holocrystalline rock - both on time scales appropriate to the thermal decay of the waste.

We all know the same physical and chemical principles apply to crystallization rates, but those principles are modified by the surrounding environment. Recrystallization of a 3 inch core of rock in no way compares to cooling of a batholith 5 km below the surface. For you to deduce such a thing... well, I'd accuse you of being an uber-uniformitarian. :teeth:

This seems a very grudging comment. Very few crystallization studies have made use of multiple component magmas and even fewer on natural granite. Gibb and Attrill have not just done interesting ork, they have significantly advanced our knowledge of the crystallization of multiple component magmas.
As I said, I personally find it interesting.


You are confusing two issues. We are here discussing crystallization rates, not the cooling of granite plutons.
Dave, don't patronize me. I know full well what we've been discussing here... and it AIN'T crystallization rates!!


This sort of comment appears to me to minimise the importance of a great deal of empirical work.
Rather interesting statement coming from you.



... claiming (as you have above) that there are other agendas which make my arguments unsound. I am not impressed.

Has a bitter taste, doesn't it? I know I don't like it either.

Besides Dave, you DO have another agenda. You need to prove the world is not 4.5 billion years old.

[kuboes1831]

David , I looked at your new book today . Why did you avoid the evidence on the age of the earth? Is the evidence for an old earth so strong and for a young earth so weak that you avoided it?

Be honest and admit all you say flies in the face of all scientific evidence

[geochron]

Sorry, but Gibb is reaching here. He's done everything possible to create a controlled laboratory environment and then infers that this is a natural process.



I don't know if you've read the paper, but in my opinion they aren't the ones who are reaching. They're writing for an audience who aren't as hopelessly confused as dtyler. I don't interpret any of the paper as inferring that this is a natural process. As I read the paper...

1. It's predicted that radioactive waste will cause generation of a partial melt.
2. It's unclear how that melt will evolve and solidify as the heat source decays
3. It's known that silicic melts can crystallise quickly, but will this one under a heating/cooling process similar to that expected from radioactive waster?

dtyler seems hooked on the "crystallise quickly" bit of the paper, but it's been known for yonks that acid magmas can crystallise quickly. That's what is so absurd about his argument.

[aniso]

I don't know if you've read the paper, but in my opinion they aren't the ones who are reaching. They're writing for an audience who aren't as hopelessly confused as dtyler. I don't interpret any of the paper as inferring that this is a natural process. As I read the paper...

1. It's predicted that radioactive waste will cause generation of a partial melt.
2. It's unclear how that melt will evolve and solidify as the heat source decays
3. It's known that silicic melts can crystallise quickly, but will this one under a heating/cooling process similar to that expected from radioactive waster?

dtyler seems hooked on the "crystallise quickly" bit of the paper, but it's been known for yonks that acid magmas can crystallise quickly. That's what is so absurd about his argument.

Yeah, you're likely right on this. I'm getting confused by what David says they say and what they really say. This thread is getting tiresome.

[geochron]

I know what you mean.

It's been another eyeopener for me showing how far YEC is from real science. All this selective quoting is ridiculous.


Though you grind a fool in a mortar with a pestle along with crushed grain,
Yet his foolishness will not depart from him.

[dtyler]

Oh Man! I don't believe dtyler is still defending this ludicrous position.
I am also reaching a position of incredulity at the resonses that are being offered to an argument that is essentially very simple. I can only think that those who are contradicting me are confusing the granite recrystallisation issue with other more contentious topics.

Comment: It doesn't say this anywhere in the conclusion. They say it recrystallises, they don't say it regains its original texture. That's because, in fact, it doesn't.
"With regard to recrystallization, the requirement for a suitable host rock is that its partial melts can be crystallized to a fine- to medium-grained holocrystalline rock when cooled at rates no slower than those likely to prevail around a package of decaying HLW." (p.131 of Lithos paper). The reference to fine- to medium-grained granite is because that's what they start with. Their conclusions are positive about meeting this requirement. "Fine- to medium-grained" is the sense in which I use the term "texture". I willingly accept that textural changes are apparent at a more detailed level of analysis (as would be visible in thin section) - but the word texture is commonly linked to hand specimens, and that's how I use it here. I've already quoted this: "It has the mineralogy and texture of granite..." (p.125 of Lithos paper). "The sample has completely solidified to a fine- to medium-grained holocrystalline granite" (p.124)

No, read more carefully - you've been making this same kindergarten error for days now. They're talking about the rates at which silicic melts can crystallise. Such melts don't always crystallise to granites - sometimes they crystallise quite quickly to fine grained rocks called rhyolites. It is in fact common knowedge that they can "crystallise orders of magnitude faster than this" - why do you think that assertion is not backed up by a reference?
I have answered this several times. Of course, acid magmas can crystallise rapidly to form rhyolites. That is common knowledge. But why are you making this point? A rhyolitic texture is *not* observed in the recrystallisation experiments. What would be predicted before the experiments? Those who link granite crystallisation to timescales measured in thousands of years would predict that the phenocrysts would be encased in a groundmass of rhyolite. Those who link granite crystallisation to timescales indicated from experimental petrology labs would anticipate (at least) significant regrowth around phenocrysts. The experiments have abundantly confirmed that the previously determined crystallisation rates for simple magmatic liquids also apply to the complex fluids of granite partial melts.

This paper investigates a specific effect of partially melting a granite and examining what is produced - the data are extremely relevant to the nuclear waste disposal industry. Details such as the effect of water and cooling rate on crystallisation (esp in the Lithos paper) may well be relevant to studies of the crystallisation of natural acid magmas (again, notice they don't say "granites") - but as far as the assertion that acid magmas can crystallise relatively quickly goes this paper tells us nothing much new. It won't carry the load you are trying to put on it, and you wouldn't be trying to make it carry that load if you knew basic igneous petrology.
I am wondering what you think the load is that I am putting on the results. I cannot see any difference between what I am saying and the conclusions of the authors!
You say "notice they don't say "granites"" - but they do not avoid using the word! "Recrystallization experiments on the granite are shown ..." (p.123 of Lithos paper, also p.129). "Crystal growth rates for quartz, alkali feldspar and biotite were derived from the cooling experiments on granite E93/7 with a range of H2O contents ..." (p.130). "Further, it suggests that cooling the granite over its normal solidification range 10 times more slowly will result in a roughly two and a half times increase in grain size." (p.131)

The word "medium" appears twice in their Geology paper. (I have it online and can search). Neither time does it refer to their results.
"The sample has completely solidified to a fine- to medium-grained holocrystalline granite" (p.124). This was a result.

Indeed, I recommend people read the Lithos paper to get a sense of what they are talking about. But notice again that they don't say "granites".
The quotes above (p. 129, 130, 131) all refer to "granite" when they mean 'granite partial melt'.

And since two can play at partial quoting, I'll leave you with this from their Lithos paper:
"Crystal growth rates for the main phases formed during cooling are linearly proportional to total H2O content and decrease from alkali feldspar through biotite to quartz. Recrystallizing the partially melted granite at 0.1 [degree] C/h compared with 1 [degree] C/h increases grain size by a factor of f2.5."
So grain size does depend on cooling rate after all!
If you have to resort to this, you really are scaping the barrel! I have never questioned this association. The issue has always been *timescales*.

I am fast running out of anything new to say. I am beginning to repost things I have previously posted. The responses I am getting are either not engaging with the issue or are trivialising it. Maybe we ought to slow down and reflect more.

[Monkey Boy]

I have never questioned this association. The issue has always been *timescales*.

If you wish to use this paper to claim short timescales for the formation of coarse-grained granite textures in naturally occurring batholiths, then don't you think it is imperative for you to show that the experimental conditions under which rapid crystallization occurs are representative of those thought to exist during the formation of said batholiths?

[rach12]

David, what paper are you now quoting from? The Lithos paper or the Geology paper?

[dtyler]

If you wish to use this paper to claim short timescales for the formation of coarse-grained granite textures in naturally occurring batholiths, then don't you think it is imperative for you to show that the experimental conditions under which rapid crystallization occurs are representative of those thought to exist during the formation of said batholiths?

This is the antithesis of debate! Where have I claimed that the paper demonstrates short timescales in naturally occurring batholiths? We are getting nowhere in this exchange because straw men are continually being erected and fired at.

Here is a resume of how we got into this discussion. It started with a comment from me in post#1. I was commenting on ways in which people read time into geological structures:
DT: 2. Igneous processes tend to be stretched out over thousands or even millions of years, but this expectation needs to be revised. Whether we are considering magma segregation, magma transport to the surface, emplacement or cooling: all these processes can take place much faster than previous generations of geologists surmised.
You responded with this in Post #3:
MB: Geologists aren't stupid you know. There are ways to get a rough measure of the timescale of an event. As just one example, the speed of cooling of an igneous formation can be roughly gauged by looking at the size of the crystals in the rock. The larger the crystals, the slower the cooling.
Since I perceived this as an example of uniformitarian thinking, it did not escape further comment from me in Post #7:
You are right: geologists are not stupid. It is no reflection on the integrity of geologists to say that they also bring presuppositions to the data that affect their interpretation of it. My concern is with those who can't or won't agree with this comment. The example of magma cooling and crystallisation is a good one. For years, this was used as an argument for vast ages for granite crystalisation. Then laboratory studies started to show that the ages might not be so long. A recent study says that the time scale can be "years as opposed to millenia". (Then comes a quote to the “Geology” paper).
Please note the following:
1. This was to support my general claim that timescales tend to be stretched out without support from empirical data.
2. This was to counter your defence of long timescales by reference to the texture of crystalline rocks.
3. I was not using the “Geology” paper to say that it proved short timescales in the formation of large igneous bodies, but that it demonstrated the mistaken view that long timescales can be inferred from the texture of crystallised magmas.

Let’s move on to Post #22:
DT: The point I was making was that large crystals do not imply long timescales. We have known about this for over 20 years, but the message is taking a long time to take root.
Again, note that I am not using the paper to argue for short timescales, but to deny the association of large crystals and long timescales. You replied:
MB: I know that's the point you want to make, but the quoted paper does not make it.
Since that is *exactly* the point the paper does make, I have persisted. The more I have persisted, the more I find that I am understanding the original paper correctly.

Before I conclude, I'll make a comment on: then don't you think it is imperative for you to show that the experimental conditions under which rapid crystallization occurs are representative of those thought to exist during the formation of said batholiths?
I'm repeating myself because we've been through this before. There are two distinct issues here: crystallisation (which is linked to the physics and chemistry of cooling magmas) and the emplacement/cooling of large igneous bodies. We have not started discussing the latter. This is not because I have nothing to say - I'm prepared to start a new thread on it! It is because I want to establish the principle that long timescales cannot be inferred from the sizes of crystals.
Further, does the cited paper reporting on laboratory experiments have a bearing on the formation of granite bodies? Are the conditions in the lab in any way representative of the Earth's granites? I have argued that, since the findings are the best description yet of how natural magmas solidify, they are relevant. They give us indications of *minimum times* of formation of granitic textures.
Do the authors think their laboratory work is relevant to understanding the formation of igneous bodies. They certainly do. Excuse the re-posting, but the message needs to be absorbed:
"While the experiments reported in this paper were undertaken primarily in connection with radioactive waste disposal schemes, it should not be overlooked that the results are also of considerable relevance for the natural crystallization of acid magmas. This applies particularly to the interpretation of textures and grain sizes in obsidians, pitchstones and fine- to medium-grained, crystalline, felsic rocks." (Lithos paper - from the conclusion).

[SteveF]

1. This was to support my general claim that timescales tend to be stretched out without support from empirical data.
Er, what about radiometric dates? Are they not empirical enough for you?

Oh and when will you get round to publishing the empirical data suggesting with a young earth (not to mentioning how Noah was alive during the Archean)? Pointing out flaws (if accurate) in an area of mainstream geology doesn't validate your 'model' by default. Positive evidence would be ince.

[rach12]

I'm repeating myself because we've been through this before. There are two distinct issues here: crystallisation (which is linked to the physics and chemistry of cooling magmas) and the emplacement/cooling of large igneous bodies. We have not started discussing the latter. This is not because I have nothing to say - I'm prepared to start a new thread on it! It is because I want to establish the principle that long timescales cannot be inferred from the sizes of crystals.

I see absolutely no reason why we can't discuss the implications of crystallization rates as they relate to emplacement/cooling of igneous bodies in this thread, but if you want to start a new thread, go for it.


And David, you have still not adequately supported your stance that large crystal sizes do not require long time periods.

[Monkey Boy]

Where have I claimed that the paper demonstrates short timescales in naturally occurring batholiths?

I didn't say that you did. I said you are using this paper to make (support) that claim. If you are not claiming that coarse granitic textures in natural batholiths can be formed in short timescales, then I don't know what this debate is about.

3. I was not using the “Geology” paper to say that it proved short timescales in the formation of large igneous bodies, but that it demonstrated the mistaken view that long timescales can be inferred from the texture of crystallised magmas.

The problem I have with your line of argument is that you keep wanting to divorce the crystallization process from the context in which it occurs. Sure, there may be crystallization processes that can occur rapidly, but if those processes don't apply to real rocks, what relevance are they?

Again, note that I am not using the paper to argue for short timescales, but to deny the association of large crystals and long timescales.

I will only note how completely context-free your claim is. I do not doubt there exist contexts in which crystal size and cooling time are not related. The question is: do those contexts bear sufficient resemblance to the context in which real rocks are formed?

Since that is *exactly* the point the paper does make, I have persisted. The more I have persisted, the more I find that I am understanding the original paper correctly.

I don't believe there was much debate on the conclusions of the paper. The issue was always the applicability of the paper's findings to current models of igneous rock formation.

I'm repeating myself because we've been through this before. There are two distinct issues here: crystallisation (which is linked to the physics and chemistry of cooling magmas) and the emplacement/cooling of large igneous bodies.

And thus you have illustrated one of the fallacies of creationist thinking. In the real world, these questions are intimately related and cannot be so conveniently compartmentalized. It does no good to attempt answers to one without understanding the implications to the answer to the other.

We have not started discussing the latter. This is not because I have nothing to say - I'm prepared to start a new thread on it! It is because I want to establish the principle that long timescales cannot be inferred from the sizes of crystals.

If you would add the word "alone" to the principle end of that last sentence, I would agree to it completely. On the other hand, you seem to be arguing that the word "ever" needs to be inserted between "cannot" and "be".

Further, does the cited paper reporting on laboratory experiments have a bearing on the formation of granite bodies? Are the conditions in the lab in any way representative of the Earth's granites? I have argued that, since the findings are the best description yet of how natural magmas solidify, they are relevant.

"Best description yet" is hyperbole to the point of silliness.

They give us indications of *minimum times* of formation of granitic textures.

But do they give us the minimum times of the formation of such textures in *real rocks*?

Do the authors think their laboratory work is relevant to understanding the formation of igneous bodies. They certainly do. Excuse the re-posting, but the message needs to be absorbed:
"While the experiments reported in this paper were undertaken primarily in connection with radioactive waste disposal schemes, it should not be overlooked that the results are also of considerable relevance for the natural crystallization of acid magmas. This applies particularly to the interpretation of textures and grain sizes in obsidians, pitchstones and fine- to medium-grained, crystalline, felsic rocks." (Lithos paper - from the conclusion).

IOW: "There may be some natural contexts that resemble our experimental conditions for which our results may be instructive."

I see no problems with that.

[aniso]

This is the antithesis of debate! Where have I claimed that the paper demonstrates short timescales in naturally occurring batholiths? We are getting nowhere in this exchange because straw men are continually being erected and fired at.

Where did MB claim that large crystal size in laboratory experiments results from slow cooling?

Here is a resume of how we got into this discussion. It started with a comment from me in post#1. I was commenting on ways in which people read time into geological structures:

You responded with this in Post #3:

Since I perceived this as an example of uniformitarian thinking, it did not escape further comment from me in Post #7:

Since we perceived that this was another example of extrapolating from a special laboratory case to the general case of all plutons, you post did not escape comment, either.

Please note the following:
1. This was to support my general claim that timescales tend to be stretched out without support from empirical data.

Then you can say that this experiment shows how any grantic pluton formed? You conveniently forget that there is plenty of empirical data that rhyolite flows cooled faster than granite intrusions...

2. This was to counter your defence of long timescales by reference to the texture of crystalline rocks.

And we were countering your defense of short timescales.

3. I was not using the “Geology” paper to say that it proved short timescales in the formation of large igneous bodies, but that it demonstrated the mistaken view that long timescales can be inferred from the texture of crystallised magmas.

And we have state that the experiment is of limited application in the formation of large plutons.

Basically, I get the impression that you think all plutons formed this way. Is that correct?

[rach12]

All David has demonstrated is that rapid cooling results in fine/aphanitic grain sizes - we already knew that. He keeps insisting however, that these studies (that only produced fine grain sizes) prove that we cannot use igneous texture to infer long time scales.

Obviously the logic escapes me.

Even his example, the Pine Valley porphyry, has a glassy groundmass and was found to have been emplaced at at depth of <250 meters. Now had the intrusion been emplaced at 5 km and exhibited a glassy groundmass, THEN I would be impressed and intrigued.

But I guess since we're just discussing crystallization rates, talk of cooling plutons, or laccoliths even, is misplaced...:nc:

[geochron]

All David has demonstrated is that rapid cooling results in fine/aphanitic grain sizes - we already knew that. He keeps insisting however, that these studies (that only produced fine grain sizes) prove that we cannot use igneous texture to infer long time scales.


The crux of the matter, identified very succinctly.

It has long been well known that these magmas can crystallise rapidly to produce aphanitic textures - the paper even tells us this "There is good reason..." (endlessly quoted by dtyler who ironically still doesn't understand what it's referring to). For some reason our correspondent keeps going on about this paper as if that piece of information is new and is about to rock (no pun intended) the geological community to its very foundations.

"Aaaahhh silicic magmas can crystallise quickly - hold the front page of Nature and book my ticket to Stockholm".

None of which, as you say, has anything whatsoever to do with whether coarse textures imply long cooling times. That is not a straightforward subject, I think we can all agree, but it's not touched on by the paper being discussed here.

To reiterate, if anyone wants to know what this quote means...

""While the experiments reported in this paper were undertaken primarily in connection with radioactive waste disposal schemes, it should not be overlooked that the results are also of considerable relevance for the natural crystallization of acid magmas. This applies particularly to the interpretation of textures and grain sizes in obsidians, pitchstones and fine- to medium-grained, crystalline, felsic rocks."

...they really should read the Lithos paper. It's not a quote that should be removed from its context.

There's a reason real scientists don't by and large debate one another by quoting fragments of one another's papers. In fact, it's a habit we try to train our first year geology undergraduates out of in their essay writing.

[grmorton]

1. This was to support my general claim that timescales tend to be stretched out without support from empirical data.

I am with Steve Forden. What do you do with 75,000 feet of sedimentary material deposited along the S. Louisiana coast line, which you claim can be deposited in 2000 years? You have never, ever explained how. That thickness of sedimentary material is most definitely empirical data.

What do you do with the 15,000 layers of burrowed shale in the Haymond formation? or the 6 million couplets of the Green River, or the 40 million layers in the Newark Basin? That most certainly is empirical data as well.

[dtyler]

I didn't say that you did. I said you are using this paper to make (support) that claim. If you are not claiming that coarse granitic textures in natural batholiths can be formed in short timescales, then I don't know what this debate is about.
That, I think, illustrates the problem. There are other agendas in this debate which I am not party to. You wrote the words above in response to my question: "Where have I claimed that the paper demonstrates short timescales in naturally occurring batholiths?". Clearly, I am under the impression that I have not made this claim - and have only started to recognise that herein lies the problem. You and your co-posters are all under the misconception that I am appealing to this paper to support the claim that
"coarse granitic textures in natural batholiths [*were*] formed in short timescales"! That explains why you have charged me with abuse and wrongly citing the paper. The advice I would give to you all is: engage with the real argument rather than creating an argument that you are comfortable with.

I have told you what the debate is about in post #95. It is about a specific example of uniformitarianism embedded in the thinking of most contemporary geologists. That is what I want to draw attention to. I want you to realise that when I say that uniformitarianism is alive and well on this list, it really is.

The problem I have with your line of argument is that you keep wanting to divorce the crystallization process from the context in which it occurs. Sure, there may be crystallization processes that can occur rapidly, but if those processes don't apply to real rocks, what relevance are they?
That's because they are distinct issues. "Divorce" is too strong a word. The physics and chemistry of processes is common ground for whatever models are invoked for real rocks. The snare of uniformitarianism is that people fail to recognise these distinctions.

I will only note how completely context-free your claim is. I do not doubt there exist contexts in which crystal size and cooling time are not related. The question is: do those contexts bear sufficient resemblance to the context in which real rocks are formed?
It is intentionally focused on the physics and chemistry of magmatic fluids - leaving aside models of emplacement. I have already answered the question several times.

[Monkey Boy]

That, I think, illustrates the problem. There are other agendas in this debate which I am not party to. You wrote the words above in response to my question: "Where have I claimed that the paper demonstrates short timescales in naturally occurring batholiths?". Clearly, I am under the impression that I have not made this claim - and have only started to recognise that herein lies the problem. You and your co-posters are all under the misconception that I am appealing to this paper to support the claim that "coarse granitic textures in natural batholiths [*were*] formed in short timescales"! That explains why you have charged me with abuse and wrongly citing the paper. The advice I would give to you all is: engage with the real argument rather than creating an argument that you are comfortable with.

It is quite clear that this is nothing more than a lame attempt at a face-saving exit. Arguing *against* long time scale models for the formation of coarse granitic textures in natural settings clearly is the same thing as arguing *for* short timescales in at least some of those settings. By casting this all as some kind of lesson on uniformitarianism, you're just trying to obscure the fact that you were caught red-handed at the quote mine.

I have told you what the debate is about in post #95. It is about a specific example of uniformitarianism embedded in the thinking of most contemporary geologists. That is what I want to draw attention to. I want you to realise that when I say that uniformitarianism is alive and well on this list, it really is.

And it will remain unashamedly alive and well as long as it continues to generate productive and testable explanations for the earth's geology. (Before you jump all over this, this is not to say that the role of catastrophe isn't also understood and appreciated).

That's because they are distinct issues. "Divorce" is too strong a word. The physics and chemistry of processes is common ground for whatever models are invoked for real rocks.

The physics and chemistry of rock formation is most certainly affected by the emplacement model. How you can continue to ignore that is baffling.

The snare of uniformitarianism is that people fail to recognise these distinctions.

Back to where we started, eh? Geologists are too stupid to realize their thinking has been clouded by "the snare".

It is intentionally focused on the physics and chemistry of magmatic fluids - leaving aside models of emplacement. I have already answered the question several times.

This smacks of revisionism to me. Where were the qualifications back on page 2 that you were only talking about "magmatic fluids" and not actual rocks?

[SteveF]

I have told you what the debate is about in post #95. It is about a specific example of uniformitarianism embedded in the thinking of most contemporary geologists. That is what I want to draw attention to. I want you to realise that when I say that uniformitarianism is alive and well on this list, it really is
Of course its alive and rightly so. It is a perfectly vaild approach to science and nothing whatsoever that you have posted suggests otherwise. You appear to also be stuck in the kind of rigid thinking that defined geology many decades ago and refuse to acknowledge that the principles behind the modern science are complex and take account of variable rates etc.

Furthermore, you have provided no reasonable, scientific alternative.

Your attempts to tear up the geological sciences are woeful because you fail to show significant problems in current thinking and have no valid replacement. Furthermore, these attempts are mostly conducted on TWeb. You are hardly burying yourself in the rigorous peer reviewed environment of mainstream geology and so have little chance of making any difference. If you have any confidence whatsoever in your ideas, why haven't you put them forward?

[dtyler]

It is quite clear that this is nothing more than a lame attempt at a face-saving exit. Arguing *against* long time scale models for the formation of coarse granitic textures in natural settings clearly is the same thing as arguing *for* short timescales in at least some of those settings. By casting this all as some kind of lesson on uniformitarianism, you're just trying to obscure the fact that you were caught red-handed at the quote mine.
You are still restating my argument in a form that fits your mould. As long as you do this, I think it should be apparent to any reasonable-minded person that the face-saving exit is being authored by you.

[dtyler]

Your attempts to tear up the geological sciences are woeful because you fail to show significant problems in current thinking and have no valid replacement.
The last thing I want to do is to tear up the geological sciences! I've spent my whole working life (and my time as a student) being positive about science and I do not intend to change now. My arguments are for *good* science. Many aspects of geological science are in urgent need of revision because they are still steeped in Lyellian traditions. This thread has been dominated by discussions of whether granitic textures necessarily imply long timescales - and the answer plainly is *no*. These textures can potentially emerge in timespans of 1-10 years. I interpret opposition to this empirical work as, at best, a relic of Lyell, and at worst, anti-science.

[rach12]

The last thing I want to do is to tear up the geological sciences! I've spent my whole working life (and my time as a student) being positive about science and I do not intend to change now. My arguments are for *good* science. Many aspects of geological science are in urgent need of revision because they are still steeped in Lyellian traditions. This thread has been dominated by discussions of whether granitic textures necessarily imply long timescales - and the answer plainly is *no*. These textures can [B}potentially[B] emerge in timespans of 1-10 years. I interpret opposition to this empirical work as, at best, a relic of Lyell, and at worst, anti-science.
Again David, all you have shown is that fine-grained *granite* forms rapidly and we already knew that. What you have not shown is that coarse grain sizes can develop in that time period and therefore you have not shown why it's wrong to infer long timescales.

In practice, we start out inferring long time until some other evidence tells us to rethink our model. And that was beautifully illustrated in the OP.

No one has yet been able to show that coarse grained granite can form in such a time period. Research suggests it MAY be possible - nothing more. Yet you sit there and accuse us of antiquated methodologies because we refuse to assume coarse grains will also develop in such a short timescale. Give me a paper that shows rapakivi texture developing in days and then you'd have made your point. Until then, good science will continue as always - with a skeptical eye.



Now, I'd actually like to hear your comments on the Pine Valley intrusion since that is what the OP is about. Unless of course you've put me on ignore... :smile:

[Monkey Boy]

You are still restating my argument in a form that fits your mould.

If true, it's not intentional. Could someone out there restate David's argument in a way that is easier to understand and at the same time explain how it differs from my restatement of it?

[aniso]

The last thing I want to do is to tear up the geological sciences!

No, you only want to trash the genereations that have come before you, along with their observations, ideas, and theories. All without a clue as to what they actually contributed in the way of hard work and sensible interpretation.

I've spent my whole working life (and my time as a student) being positive about science and I do not intend to change now. My arguments are for *good* science.

Your arguments are for ivory towered philosophy of science where there the only bad ideas are ones that disagree with yours.

Many aspects of geological science are in urgent need of revision because they are still steeped in Lyellian traditions.

You have not made a compelling argument for this. This whole thread has been a refutation of this statement. Science is working, as usual, without the myopic eyes of fundamental religionists.

This thread has been dominated by discussions of whether granitic textures necessarily imply long timescales - and the answer plainly is *no*.

Nope. The answere is plainly, that 'some fine grained granitic textures might have occurred during relatively rapid cooling.' You have oversimplified the results to the point of tragedy.

These textures can potentially emerge in timespans of 1-10 years.

Apparently, Some can. If they are fine-grained enough.

I interpret opposition to this empirical work as, at best, a relic of Lyell, and at worst, anti-science.

I interpret your extrapolation of this work to be a self-serving, obsessive relic of fundamentalist anti-logic.

So come clean for once here, David: Do you believe that this process that we have been discussing is how all granites formed? Try to give us an honest answer and not some self-righteous sermon about good science and Lyellian relics.

[aniso]

It is intentionally focused on the physics and chemistry of magmatic fluids - leaving aside models of emplacement. I have already answered the question several times.

No. This discussion has revolved aroung the partial melting and recrystallization of a pre-existing granite by metamorphic fluids. There was no granitic magma involved, particularly at that outset (that is, unless you think that every granite magma came from a precursor granite). Your whole argument has gotten so silly that my head hurts...

[grmorton]

The last thing I want to do is to tear up the geological sciences! I've spent my whole working life (and my time as a student) being positive about science and I do not intend to change now.

Two comments David. If what you are trying to do, (explain geology within an 8000 year old earth) isn't an attempt to tear up the geological sciences, I don't know what could possibly be called 'tearing up geological sciences'! You have to ignore the laws of meander formation to have channels with meanders form in the time you allow. You must have near instantaneous cooling of huge batholiths, instantaneous cooling of the many kilometers thick oceanic crust, you have to have altered radioactive decay, you have to have animals burrow with super-animal feats of exertion. You have to ignore all the animals wandering around on the Cambrian and Ordovician strata at the height of your flood. You have to ignore the 75,000 feet of sediment (still unexplained after all these years) along the Louisiana coastline. You have to ignore the fact that not a single modern mammalian species is fossilized in the geologic column earlier than the Miocene. You have to believe that the 2000 years of your recolonization model was a period of rapid meteor influx, including some like Chicxulub which probably wiped out much of the life on earth. To you, it was nothing but an unimportant event quickly forgotten by the next day. I don't know how anyone can say you are not tearing up geological science, not to mention astronomical science and the laws of physics. Sorry David, but you views aren't any better than those of Henry Morris.

Secondly, years ago, I used to think you were the most reasonable creationist. I don't think that anymore. Whatever you are doing is not to be confused with science. Science requires that people acknowledge what they don't explain, pay attention to contrary data, pay attention to problems and deal with them and then it requires that one change his mind once in a while.
You have done none of the above. So whatever you are positive about, it ain't science.

Unfortunately, you look like a guy on the Titanic who thinks that if he can just get the rubber ducky to float in the stateroom bathtub , the ship won't sink.

[dtyler]

Again David, all you have shown is that fine-grained *granite* forms rapidly and we already knew that. What you have not shown is that coarse grain sizes can develop in that time period and therefore you have not shown why it's wrong to infer long timescales.
"It suggests that cooling the granite over its normal solidification range 10 times more slowly will result in a roughly two and a half times increase in grain size. To the best of our knowledge, this is the first time this relationship has been even approximately quantified" (Attrill & Gibb, Lithos, 67, 2003, p.131). In addition to this, the authors point out that the largest crystals and the fastest growth rates occur in water-saturated cooling experiments. Water has two effects: suppressing nucleation and accelerating growth. These empirical findings allow the same principles we have previously discussed to apply to coarser textures - with some increase in time requirements, but we are still taling about years (not "long timescales").

No one has yet been able to show that coarse grained granite can form in such a time period. Research suggests it MAY be possible - nothing more. Yet you sit there and accuse us of antiquated methodologies because we refuse to assume coarse grains will also develop in such a short timescale.

No, I accuse you of being uniformitarians on this issue because you persist in thinking that granitic textures (of whatever coarseness) are an indication of long timescales.

Give me a paper that shows rapakivi texture developing in days and then you'd have made your point. Until then, good science will continue as always - with a skeptical eye.
I have never argued for "days". It would be very interesting to know how rapakivi textures were formed. I think about this every time I see them in polished building stones. The discussion we have had does offer some leads: there seems to be a lot of water around with these granites - and this favours the growth of large crystals. Some have suggested the rounded appearance is due to abrasion as the phenocrysts are moving to the place where the magmas solidified. I cannot help but think that relatively rapid depositional models will yield positive results.

Now, I'd actually like to hear your comments on the Pine Valley intrusion since that is what the OP is about. Unless of course you've put me on ignore... :smile:
I've made the points I wanted to make. Do you really want me to make further comments?

[rach12]

I've made the points I wanted to make. Do you really want me to make further comments?

Why not?

For example, in your recolonisation model, where in time would you place the Pine Valley intrusion? What about the other intrusions in the area?


In your model, where in time would you place:

-- the country rocks?

-- the iron deposits associated with the intrusions?

-- the massive slides?

[dtyler]

For example, in your recolonisation model, where in time would you place the Pine Valley intrusion? What about the other intrusions in the area?
In your model, where in time would you place:
-- the country rocks?
-- the iron deposits associated with the intrusions?
-- the massive slides?
I will be brief. I would locate all these over 100 years after the Mabbul destruction.

[SteveF]

I will be brief. I would locate all these over 100 years after the Mabbul destruction.
Why?

[rach12]

I will be brief. I would locate all these over 100 years after the Mabbul destruction.
lol Yes, that was brief.

Since I'm not up on the sequence and timing of events in your recolonisation model (how long ago was the Mabbul?), could you post a bulleted summary? Or a nice time line?

Do you have a diagram depicting how your timeline and sequence of events correlate to the Geologic Timescale?

[SteveF]

lol Yes, that was brief.

Since I'm not up on the sequence and timing of events in your recolonisation model (how long ago was the Mabbul?), could you post a bulleted summary? Or a nice time line?

Do you have a diagram depicting how your timeline and sequence of events correlate to the Geologic Timescale?
I agree, search all I can on the net I've not been able to find any details on the recolonisation 'model' (assuming there is any). Could you provide a link please?

[Kulindrichnus]

Secondly, years ago, I used to think you were the most reasonable creationist. I don't think that anymore. Whatever you are doing is not to be confused with science. Science requires that people acknowledge what they don't explain, pay attention to contrary data, pay attention to problems and deal with them and then it requires that one change his mind once in a while.
You have done none of the above. So whatever you are positive about, it ain't science.

Unfortunately, you look like a guy on the Titanic who thinks that if he can just get the rubber ducky to float in the stateroom bathtub , the ship won't sink.

'Most reasonable' creationist? dividing creationists up by their reason is like dividing theives up by their houour. (much the same applies to creationists and honour, although to credit the criminal community it does not follow for thieves and reason).

I straightaway took David as the most woeful creationist I've ever encountered and nothing I've seen here or elsewhere has altered that.

K

[grmorton]

'Most reasonable' creationist? dividing creationists up by their reason is like dividing theives up by their houour. (much the same applies to creationists and honour, although to credit the criminal community it does not follow for thieves and reason).

I straightaway took David as the most woeful creationist I've ever encountered and nothing I've seen here or elsewhere has altered that.

K

I won't change history or as truthful a look at my past views. It was what it was. I was wrong, of course.

[Roy]

I agree, search all I can on the net I've not been able to find any details on the recolonisation 'model' (assuming there is any). Could you provide a link please?

There're a few details at http://www.noahsarkzoofarm.co.uk/.

Roy

[SteveF]

There're a few details at http://www.noahsarkzoofarm.co.uk/.

Roy
I officially resign as a member of the human race.

[Kulindrichnus]

There're a few details at http://www.noahsarkzoofarm.co.uk/.

Roy

:lmbo: :lmbo: :lmbo: :lmbo: :lmbo: :lmbo: :lmbo: >ad infinitum

Proof that Noah was running a racket. Look at the admission prices for the Ark's farm-based analogue:
---------------------------------------------------
Adults Day Ticket £7.00, Season Ticket £35.00
Child (Aged 2-16) £5.00, £30.00
Family (2+2) £21.00, £99.00
Child Care (1+3) £19.00, £95.00
Concessions £6.00, £32.00
Group of 10+ 1 FREE
Schools, Groups & Parties 15+ £4.00 Adults & Children
---------------------------------------------------
Not many humans on the Ark, but the prices don't specify species. One must suppose all adults and young needed season tickets. If the Creationists estimate something like 15,000 animals, then Noah must've put away beer money between £450,000 and £525,000. Did the humans get concessions for holding the pee-bucket? And why give discounts for those animals whose collective noun is a 'school'? Not to mention the free offer for the eleventh punter. Noah knew full well that Yahweh was sending them in multiples of two!

Even allowing for inflation since the Bronze Age, the wily old beer-hauler must've been sober long enough to realize he was making a mint. After all, he had a god-given monopoly.......

K

[rach12]

:hi:


I'm still interested in learning about/discussing the Recolonisation Model.

[Roy]

:hi:
I'm still interested in learning about/discussing the Recolonisation Model.

:hi:!

This is all I've got...

(one obvious criticism is that apparently a lot of work went into preserving large and diverse animals which would all go extinct a couple of hundred years after the flood).

http://www.noahsarkzoofarm.co.uk/research/index.html
3. The geological record is a record of the world’s gradual recovery after the Flood.

A distinction is drawn between the ‘Flood’ proper, i.e. the initial 40-day cataclysm of God’s wrath when all terrestrial life was blotted out, and the rest of the Flood year. The Cataclysm began with waters from above pouring through the heavens, and waters from below erupting through the springs which had originally irrigated the earth. The rain was accompanied by a storm of comets (or asteroids). On the moon their impact craters are still visible today, but on the Earth they were erased by later geological activity. Astronomers refer to this event – which affected the whole Solar System – as the Early and Late Heavy Bombardments. It took place in the Hadean ‘era’, tailing off in the Archaean.



All terrestrial life was obliterated by the Cataclysm. There are no fossils from that time, no traces of antediluvian cities, no remnants even of the land itself. As Genesis says, all flesh was blotted out, as a result of the whole fabric of the land being shattered and submerged. At the same time, hugely increased levels of radioactivity heated up the Earth’s mantle, so that it melted and poured through the now emptied springs of the deep, burying the old landmass and forming the crust for a new landmass.

We do not know exactly how Noah survived the Cataclysm. As a result of the heat energy released by the impacts, most ocean life would also have been destroyed. The safest place to be would have been at the poles, where the waters were coolest and where there would have been few, if any, impacts from celestial bodies. Some marine life would have survived; perhaps also some plants, seeds and insect life. It was not until 330 days after the end of the Cataclysm that the waters had receded sufficiently for men and animals to set foot on dry ground. They would have stepped onto ground that geologists assign to the Archaean ‘era’ – newly formed, volcanic basement that had emerged from the waters some 4 months after the Cataclysm. We do not know where this was: perhaps somewhere in the centre of Africa. The ‘mountains of Ararat’ in the story should not be confused with Mount Ararat in Turkey, any more than the original Tigris and Euphrates should be confused with the rivers in modern Iraq or Cambridge in East Anglia confused with Cambridge in Massachusetts.



Post-Flood life would have been hard. For some while the animals would have lived off food from the ark. The silt around them would have been sterile, though 1,000 tonnes of manure accumulated during the year at sea may soon have transformed its fertility. For thousands of years – until the end of the Ice Age – the Earth continued to be unstable and dangerous.

The places where erosion and deposition most actively took place were the continental margins. Here shelves and basins received great thicknesses of sediment. On the other hand, the rate of deposition was often low enough for marine life to colonise these margins, as we see from the fossilised remains of their shells and, often, their burrows. Marine life was gradually recovering: algae and plankton first, then worms, shellfish and scavengers, then fish, and finally, at the top of the food chain, sharks. This sequence of recovery is recorded in the rocks designated Proterozoic and Palaeozoic.



In the second half of the Palaeozoic we get a similar sequence of terrestrial forms of life, as these too began to recover: first large amphibians, along with plants and insects, then reptiles, herbivorous and carnivorous. The sequence from reptiles to mammal-like reptiles to dinosaurs and small mammals and finally to large mammals is a sequence of different levels of metabolism (degrees of warm-bloodedness), and reflects the fact that right through Earth history the environment was continually changing and gradually cooling. Initially conditions favoured reptiles, so they multiplied and dominated the fossil record. Then they favoured dinosaurs; then large mammals. The suddenness with which these groups appear in the fossil record, usually following a catastrophic extinction event, shows that the sequence had nothing to do with Darwinian evolution. But evolution in the sense that animal kinds were continually diversifying and producing new species certainly was going on.

The last major group to appear in the fossil record was man himself. Although he had a smaller brain than today, it is well established that size of brain has nothing to do with intelligence, and in every respect there remains a huge gap between early man and the apes, his presumed ancestors. Man first appeared in Africa, where it is likely the ark ran aground, and the main reasons why he did not appear earlier in the fossil record are (1) Africa’s interior has very little geological record after the Palaeozoic, and (2) man did not spread into other continents until conditions favoured a hunting way of life.

[geochron]

There you are, you see, how dare people say this isn't "real science"

[dtyler]

:hi:!
This is all I've got...
[cite=Steven J Robinson]http://www.noahsarkzoofarm.co.uk/research/index.html
3. The geological record is a record of the world’s gradual recovery after the Flood.

A more detailed overview is at:
http://www.amen.org.uk/eh/science/flodpg/flodpg3.htm
however, this needs updating to reflect the changes in thinking in our group. It is hoped to do his later on this year.

(one obvious criticism is that apparently a lot of work went into preserving large and diverse animals which would all go extinct a couple of hundred years after the flood).
Some things I do not attempt to explain - but please remember that the Ark was not there to preserve "species" - but "kinds". If the "kind" represents the Family level of taxonomy, there was a lot of post-Flood speciation. Many of those species have become extinct, but representatives of the Family continue on.

[Monkey Boy]

A more detailed overview is at:
http://www.amen.org.uk/eh/science/flodpg/flodpg3.htm
however, this needs updating to reflect the changes in thinking in our group. It is hoped to do his later on this year.

Still no empirical evidence for a global flood 6,000 years ago I see. Maybe your group ought to start there. In the interest of *good* science, I don't imagine you'd want to let your theories get too far removed from the empirical evidence, would you?

[Roy]

Some things I do not attempt to explain - but please remember that the Ark was not there to preserve "species" - but "kinds". If the "kind" represents the Family level of taxonomy, there was a lot of post-Flood speciation. Many of those species have become extinct, but representatives of the Family continue on.

I don't suppose you could tell me where to find living species in the same Family/kind as
- tyrannosaurus rex
- indricothere
- apatosaurus
- glyptodonts
- thylacosmilus
- ankylosaurs
- triceratops
- archaeopteryx
etc?

Roy

[SteveF]

Still no empirical evidence for a global flood 6,000 years ago I see. Maybe your group ought to start there. In the interest of *good* science, I don't imagine you'd want to let your theories get too far removed from the empirical evidence, would you?
I'm quite busy so I had a quick scan. One statement leaped out at me, confirming what we all know about the 'scientific' methodoloies of YECs:

"It is vitally important that a young-earth view of geological history is developed that is in harmony with both the scientific evidence and scripture"

Er.......

[DunnySaze]

... - but please remember that the Ark was not there to preserve "species" - but "kinds". If the "kind" represents the Family level of taxonomy, there was a lot of post-Flood speciation. Many of those species have become extinct, but representatives of the Family continue on.

And also remember that even at the taxonomic level of Family there is a large number of organisms that had to loaded onto the ark. For instance, a modern list of just the bird Families would include ---

Struthionidae (Ostrich), Dromadidae (Crab Plover), Rheidae (Rheas), Haematopodidae (Oystercatchers), Casuariidae (Cassowaries), Ibidorhynchidae (Ibisbill), Dromaiidae (Emu), Recurvirostridae (Stilts & Avocets), Apterygidae (Kiwis), Burhinidae (Thick-knees), Tinamidae (Tinamous), Glareolidae (Coursers & Pratincoles), Anhimidae (Screamers), Charadriidae (Plovers), Anatidae (Swans, Geese & Ducks), Scolopacidae (Sandpipers, Snipes & Allies), Megapodiidae (Megapodes), Pedionomidae (Plains-wanderer), Cracidae (Curassows & Guans), Thinocoridae (Seedsnipes), Phasianidae (Pheasants & Partridges & Chickens), Chionidae (Sheathbills), Tetraonidae (Grouse & Allies), Stercorariidae (Jaegers & Skuas), Meleagrididae (Turkeys), Laridae (Gulls), Numididae (Guineafowls), Sternidae (Terns), Odontophoridae (New World Quails), Rynchopidae (Skimmers), Gaviidae (Loons), Alcidae (Auks), Podicipedidae (Grebes), Pteroclidae (Sandgrouse), Spheniscidae (Penguins), Columbidae (Pigeons & Doves), Diomedeidae (Albatrosses), Cacatuidae (Cockatoos), Procellariidae (Petrels & Shearwaters), Psittacidae (Parrots), Hydrobatidae (Storm-Petrels), Musophagidae (Turacos & Allies), Plecanoididae (Diving-Petrels), Cuculidae (Cuckoos, Coucals & Anis), Phaethontidae (Tropicbirds), Tytonidae (Barn & Grass Owls), Pelecanidae (Pelicans), Strigidae (Typical Owls), Sulidae (Boobies), Steatornithidae (Oilbird), Phalacrocoracidae (Cormorants), Podargidae (Frogmouths), Anhingidae (Darters), Aegothelidae (Owlet-Nightjars), Fregatidae (Frigatebirds), Nyctibiidae (Potoos), Ardeidae (Herons), Caprimulgidae (Nightjars & Allies), Scopidae (Hamerkop), Apodidae (Swifts), Balaenicipitidae (Shoebill), Hemiprocnidae (Treeswifts), Ciconiidae (Storks), Trochilidae (Hummingbirds), Threskiornithidae (Ibises), Coliidae (Mousebirds), Phoenicopteridae (Flamingos), Trogonidae (Trogons), Cathartidae (New World Vultures), Alcedinidae (Kingfishers), Pandionidae (Osprey), Todidae (Todies), Accipitridae (Hawks & Eagles), Momotidae (Motmots), Sagittariidae (Secretarybird), Meropidae (Bee-eaters), Falconidae (Falcons & Caracaras), Coraciidae (Rollers), Opisthocomidae (Hoatzin), Brachypteraciidae (Ground-Rollers), Mesitornithidae (Mesites), Leptosomatidae (Cuckoo-Roller), Turnicidae (Buttonquails), Upupidae (Hoopoes), Gruidae (Cranes), Phoeniculidae (Wood-Hoopoes & Scimitarbills), Aramidae (Limpkin), Bucorvidae (Ground-Hornbills), Psophiidae (Trumpeters), Bucerotidae (Hornbills), Rallidae (Rails), Galbulidae (Jacamars), Heliornithidae (Finfoots), Bucconidae (Puffbirds), Rhynochetidae (Kagu), Megalaimidae (Asian Barbets), Eurypygidae (Sunbittern), Lybiidae (African Barbets & Tinkerbirds), Cariamidae (Seriemas), Capitonidae (American Barbets), Otididae (Bustards), Ramphastidae (Toucans), Jacanidae (Jaçanas), Indicatoridae (Honeyguides), Rostratulidae (Painted-snipe), Picidae (Woodpeckers), Eurylaimidae (Broadbills), Aegithalidae (Long-tailed Tits), Philepittidae (Asities), Maluridae (Fairywrens & Grasswrens), Pittidae (Pittas), Acanthizidae (Australo-Papuan Warblers), Furnariidae (Ovenbirds & Furnarids), Epthianuridae (Australian Chats), Dendrocolaptidae (Woodcreepers), Neosittidae (Sittellas), Thamnophilidae (Typical Antbirds), Climacteridae (Australasian Treecreepers), Formicariidae (Ground Antbirds), Paridae (Tits & Chickadees), Conopophagidae (Gnateaters), Sittidae (Nuthatches), Rhinocryptidae (Tapaculos), Tichodromidae (Wallcreeper), Cotingidae (Cotingas), Certhiidae (Creepers), Sapayoidae (Sapayoa), Rhabdornithidae (Rhabdornis), Pipridae (Manakins), Remizidae (Penduline Tits), Tyrannidae (Tyrant Flycatchers), Paramythiidae (Painted Berrypeckers), Acanthisittidae (New Zealand Wrens), Melanocharitidae (Berrypeckers & Longbills), Atrichornithidae (Scrub-birds), Nectariniidae (Sunbirds & Spiderhunters), Menuridae (Lyrebirds), Dicaeidae (Flowerpeckers), Alaudidae (Larks), Pardalotidae (Pardalotes), Hirundinidae (Swallows & Martins), Zosteropidae (White-eyes), Motacillidae (Pipits & Wagtails), Promeropidae (Sugarbirds), Campephagidae (Cuckoo-Shrikes), Meliphagidae (Honeyeaters), Pycnonotidae (Bulbuls), Oriolidae (Old World Orioles), Chloropseidae (Leafbirds), Laniidae (True Shrikes), Irenidae (Fairy-Bluebirds), Malaconotidae (Bush-Shrikes), Aegithinidae (Ioras), Prionopidae (Helmet-Shrikes), Ptilogonatidae (Silky-flycatchers), Vangidae (Vangas), Bombycillidae (Waxwings), Dicruridae (Drongos), Hypocoliidae (Hypocolius), Callaeidae (New Zealand Wattlebirds), Dulidae (Palmchat), Corcoracidae (Apostlebirds), Cinclidae (Dippers), Artamidae (Woodswallows), Troglodytidae (Wrens), Pityriaseidae (Bristlehead), Mimidae (Thrashers & Mimids), Cracticidae (Butcherbirds & Bellmagpies), Prunellidae (Accentors), Paradisaeidae (Birds-of-Paradise), Turdidae (Thrushes), Cnemophilidae (Cnemophilines), Regulidae (Kinglets), Ptilonorhynchidae (Bowerbirds), Sylviidae (Old World Warblers incl. Cisticolas), Corvidae (Crows, Jays & Allies), Polioptilidae (Gnatcatchers), Sturnidae (Starlings & Mynas), Muscicapidae (Old World Flycatchers), Buphagidae (Oxpeckers), Platysteiridae (Batises & Wattle-eyes), Passeridae (Old World Sparrows), Rhipiduridae (Fantails), Ploceidae (Weavers), Monarchidae (Monarch-Flycatchers), Estrildidae (Waxbills), Grallinidae (Magpie-larks), Viduidae (Indigobirds), Petroicidae (Australo-Papuan Robins), Vireonidae (Vireos), Pachycephalidae (Whistlers), Fringillidae (Finches), Picathartidae (Rockfowl), Drepanididae (Hawaiian Honeycreepers), Timaliidae (Babblers), Parulidae (New World Warblers), Pomatostomidae (Pseudo-babblers), Cardinalidae (Cardinals, Grosbeaks & Allies), Paradoxornithidae (Parrotbills), Thraupidae (Tanagers), Orthonychidae (Logrunners),Emberizidae (Sparrows & Old World Buntings), Cinclosomatidae (Whipbirds & Quail-Thrushes), and Icteridae (Icterids).

I may be missing a few.

And this is not counting any bird Families that may have gone extinct since the ark landed (e.g. the dodo).

There is a lot of super-speed speciation from the "kind" after that. In the Family Anatidae (ducks and geese) alone there are now some 148 different species, and even more species of woodpecker (216) and parrot (360).

***Edited to alter format slightly, primarily added italics***

[Monkey Boy]

There is a lot of super-speed speciation from the "kind" after that. In the Family Anatidae (ducks and geese) alone there are now some 148 different species, and even more species of woodpecker (216) and parrot (360).

Yes, it becomes quite ironic that creationists need super-rapid ... er ... evolution ... to make their hypothesis plausible in that regard, yet they continue to deny the efficacy of ... um ... evolution ... to produce diversity in the first place.

Can you say "cognitive dissonance"?

[Roy]

I'm quite busy so I had a quick scan.

A few more highlights:

In Grand Canyon, just below a prominent cliff formed by the Redwall Limestone, there is a claimed gap of 100 million years of missing Ordovician and Silurian deposits (Roth 1988). The layers above this gap sit conformably on the layers beneath as though no long time gap had elapsed between them.

Presumably a 100 million year gap would required the layers above the gap to not sit comfortably on the layers below it. Maybe they would only touch in a few places, or be held up by pillars, or employ some sort of maglev device? Or perhaps they would fidget and jiggle about.

We should remember again the violence of the Flood. The original land surface was being stripped away, there was widespread volcanism and metamorphism, physical dismemberment by buffeting waters, abrasion and pulverisation by sediments, and chemical decomposition. ... These forests were thick mats of vegetation, covering thousands of square miles, that floated on the margins of the shallow pre-Flood oceans. At the start of the Flood, these mats were dislodged and drifted, probably breaking up into separate parts. As the waters drained off the continents at the end of the Flood, the floating mats were grounded, and came to rest on top of one another.

So the flood was so violent that floating animal corpses were dismembered, abraded, pulverised and attacked chemically until they vanished without trace - but floating giant ferns survived intact.

It is in the Cambrian sediments that we find the first abundant remains of complex marine invertebrates, including trilobites, molluscs, and brachiopods. These creatures can be interpreted as pre-Flood marine creatures that were washed in from pre-Flood sea-floors as the marine waters swept over the foundering continents. (Perhaps only the free-swimming creatures were swept in.)

Yes, trilobites etc are well known to be free-swimming creatures.

Robinson (1996, 1997b) has suggested that most of the rest of the Lower Palaeozoic marine fauna was not transported from pre-Flood sea-floors but grew during the Flood whenever temporarily stable conditions allowed.

So entire ecosystems appear in just days or weeks in areas which have just been completely scoured?

As the waters drained off the continents at the end of the Flood, the floating mats were grounded, and came to rest on top of one another.

... which is only possible with rising waters, not draining ones.

Significantly, the first appearance of the tetrapod (four-footed) vertebrates in the fossil record coincides with the grounding of these mats. These were essentially aquatic amphibians and reptiles that survived on the floating mats during the Flood and subsequently became the first backboned animals to repopulate the land as the waters receded. ... The amphibian and reptile tracks in the Upper Palaeozoic appear to be those of semi-aquatic creatures that were able to survive outside the Ark

So 6ft long pelycosaurs can ride out the flood on floating vegetation mats but 6in long voles can't?

The reproductive output of dinosaurs is thought to have equalled or exceeded that of rodents, and was much higher than large mammals like elephants. This would explain why dinosaurs appear in the fossil record before the mammals, which do not appear in significant numbers until the Cenozoic.

Well it might explain why dinosaurs are found in the fossil record before elephants. It doesn't explain why they are found before rabbits as well.

Furthermore, unlike the dinosaurs, which lived on extensive mudflats, mammals prefer habitats away from water, ...

... cf. otters, dolphins, manatees, ornithorhynchi, seals, walruses, beavers,
whales, water-rats, voles, yapoks and hippopotami, all of which live in deserts.

The possibility that dinosaurs living on mudflats got fossilized much more readily than those that frequented drier areas is obviously too absurd to mention.

Roy

[grmorton]

A few more highlights:

In Grand Canyon, just below a prominent cliff formed by the Redwall Limestone, there is a claimed gap of 100 million years of missing Ordovician and Silurian deposits (Roth 1988). The layers above this gap sit conformably on the layers beneath as though no long time gap had elapsed between them.

Presumably a 100 million year gap would required the layers above the gap to not sit comfortably on the layers below it. Maybe they would only touch in a few places, or be held up by pillars, or employ some sort of maglev device? Or perhaps they would fidget and jiggle about.

As one goes northwest from the Canyon, the missing strata appear in correct position in this interval. It is a very low angle unconformity which is difficult to detect at outcrop scale.

[Kulindrichnus]

......which is difficult to detect at outcrop scale.

Well no, it isn't, because the ordovician and silurian rocks are missing :wink:

Perhaps it should be called a disconformity.

K

[Roy]

Well no, it isn't, because the ordovician and silurian rocks are missing :wink:

Perhaps it should be called a disconformity.


Or a discomfortiny? That would explain the way it sits...

Roy

(sorry)

[SteveF]

Or a discomfortiny? That would explain the way it sits...

Roy

(sorry)
So you should be.:wink:

[dtyler]

The problem I have with your line of argument is that you keep wanting to divorce the crystallization process from the context in which it occurs. Sure, there may be crystallization processes that can occur rapidly, but if those processes don't apply to real rocks, what relevance are they?
Of course the processes apply to real rocks. My objective in this exchange has been to establish the simple point that you cannot look at a granite and say: the crystal sizes mean that we are dealing with thousands of years or more.

Regarding the emplacement of granite, thinking has changed dramatically over the past decade. All these changes in thinking are in the right direction, IMO. For a contemporary example, please see:

Are plutons assembled over millions of years by amalgamation from small magma chambers?
Allen F. Glazner, John M. Bartley, Drew S. Coleman, Walt Gray, and Ryan Z. Taylor
GSA Today: Vol. 14, No. 4, pp. 4–11.
Follow links from http://www.gsajournals.org/gsaonline/?request=index-html

ABSTRACT: Field and geochronologic evidence indicate that large and broadly homogeneous plutons can accumulate incrementally over millions of years. This contradicts the common assumption that plutons form from large, mobile bodies of magma. Incremental assembly is consistent with seismic results from active volcanic areas which rarely locate masses that contain more than 10% melt. At such a low melt fraction, a material is incapable of bulk flow as a liquid and perhaps should not even be termed magma. Volumes with higher melt fractions may be present in these areas if they are small, and this is consistent with geologic evidence for plutons growing in small increments. The large melt volumes required for eruption of large ignimbrites are rare and ephemeral, and links between these and emplacement of most plutons are open to doubt. We suggest that plutons may commonly form incrementally without ever existing as a large magma body. If so, then many widely accepted magma ascent and emplacement processes (e.g., diapirism and stoping) may be uncommon in nature, and many aspects of the petrochemical evolution of magmatic systems (e.g., in situ crystal fractionation and magma mixing) need to be reconsidered.

From the Introduction: In this paper, we summarize field, geochronologic, and geophysical evidence that many plutons were emplaced incrementally over significant time spans and argue that many of our fundamental assumptions regarding plutons and their relationships to host rocks must be reexamined.
------------

This reexamination needs to be done. I was willing to argue the case on TWeb, but my experience with crystallisation issue means that I will not. But I recommend this paper to you, and also the review by Petford et al (2000) which you will find referenced.

[Monkey Boy]

Of course the processes apply to real rocks. My objective in this exchange has been to establish the simple point that you cannot look at a granite and say: the crystal sizes mean that we are dealing with thousands of years or more.

We all know that was your objective. The simple matter is that you failed to establish a persuasive case for it.

Regarding the emplacement of granite, thinking has changed dramatically over the past decade. All these changes in thinking are in the right direction, IMO.

I read that paper and don't see how it is friendly at all to the young-earth position. If anything, it means that large plutons took longer to form than we thought since there now must be time for multiple intrusive events, each requiring potientially hundreds of thousands of years to cool.

This reexamination needs to be done.

Fine, the reexamination needs to be done. The earth still appears far older than your young-earth myth would allow. Happy?

[DunnySaze]

Of course the processes apply to real rocks. My objective in this exchange has been to establish the simple point that you cannot look at a granite and say: the crystal sizes mean that we are dealing with thousands of years or more.

Except you neglect to mention in this "simple point" that the process used to make the granitic texture rapidly to which you refer has nothing to do with the formation of these rocks in the first place. Science is not a cafeteria where you can select only the few facts you like and ignore the rest.

Regarding the emplacement of granite, thinking has changed dramatically over the past decade. All these changes in thinking are in the right direction, IMO. For a contemporary example, please see:

Are plutons assembled over millions of years by amalgamation from small magma chambers?
Allen F. Glazner, John M. Bartley, Drew S. Coleman, Walt Gray, and Ryan Z. Taylor
GSA Today: Vol. 14, No. 4, pp. 4–11.

So you would support their view that these plutons assemble over millions of years incrementally rather than as large single mobile bodies of magma? If they are still not right, then why not? How do you already know which direction is the right direction?

[aniso]

Of course the processes apply to real rocks.

Good. Then give us an example of where this has occurred in 'real rocks.'

My objective in this exchange has been to establish the simple point that you cannot look at a granite and say: the crystal sizes mean that we are dealing with thousands of years or more.

Are you saying that all granites formed this way, then? I think I have asked this before, but you neglected to answer. It would really clarify things here if you came clean on the subject.

Regarding the emplacement of granite, thinking has changed dramatically over the past decade. All these changes in thinking are in the right direction, IMO. For a contemporary example, please see:

Are plutons assembled over millions of years by amalgamation from small magma chambers?
Allen F. Glazner, John M. Bartley, Drew S. Coleman, Walt Gray, and Ryan Z. Taylor
GSA Today: Vol. 14, No. 4, pp. 4–11.
Follow links from http://www.gsajournals.org/gsaonline/?request=index-html

ABSTRACT: Field and geochronologic evidence indicate that large and broadly homogeneous plutons can accumulate incrementally over millions of years.

Oops! Did they say millions of years?

...

From the Introduction: In this paper, we summarize field, geochronologic, and geophysical evidence that many plutons were emplaced incrementally over significant time spans

'Significant time spans?' David, whose point are you trying to make here?

...and argue that many of our fundamental assumptions regarding plutons and their relationships to host rocks must be reexamined.

Hey, I'm all for that. However, I don't think this is an earth-shattering paradigm change. Multi-phase plutons have been recognized for ages in mineral exploration.

This reexamination needs to be done. I was willing to argue the case on TWeb, but my experience with crystallisation issue means that I will not. But I recommend this paper to you, and also the review by Petford et al (2000) which you will find referenced.

David, from all that you have shown us, the reexamination is being done... constantly! Where do you think these papers come from? You say that we desperately need to question our geological foundations and then show us references that prove it IS being done! Your argument is meaningless and you have done nothing to support a YEC position.

[dtyler]

Excuse me. I saw nothing regarding the development of a 'granitic texture' in a very short time, only evidence for rapid recrystallization under some very specific conditions. David, you are getting farther and farther from reality here. Have you actually read this paper? Do you have any other/better examples of rapidly forming granitic textures?
I thought a long-dead thread worth reviving, to mark a significant paper that has been published recently. It is difficult to pick on a representative post to trigger the response, but I have chosen the above from post #44.

The reference and abstract is below. The key thought that is relevant to this thread is: "Experimental data on crystallization rates suggest that many of the large crystals observed in granitic rocks could have grown in a matter of hours - certainly in no more than a few tens of years. Geological processes are commonly thought of as slow and continuous, but many are rapid and episodic. Granitic plutonism is of the latter kind."

For those who want a quick summary of a tortuous thread, the above is what I was saying, but I was challenged every step of the way!

Clemens, J. D. 2005. Granites and granitic magmas: strange phenomena and new perspectives on some old problems. Proceedings of the Geologists' Association, 116, 9-16.

Granitic plutons generally afford pleasant, mostly unchallenging landscapes. However, on closer inspection of some of the outcrops, one may discover some strange, beautiful and baffling examples of patterns produced by geochemical and mineralogical self-organization. Fascinating as they are, these features probably reveal little about the origins of granitic magmas. It is the more usual features that one needs to study and understand, using geophysics, geochemistry, isotope petrology, textural analysis and various kinds of theoretical modelling. Many granites are products of high-temperature melting of continental crust and there is a relationship between upper granulite-facies metamorphism and the generation of granitic magmas. The heat needed for this process commonly comes from mafic magmas intruded into the deep crust and the melting reactions take place in the absence of free fluids. The relatively low viscosity and density of hydrous granitic magmas control the ascent and emplacement processes and the viscosity is not greatly changed during crystallization and cooling, at least for the first few tens of percent crystals. Modelling shows that granite diapirism is slow and inefficient and there is little evidence of it in the geological record. The granitic melt segregates into veins, shears and dykes, eventually forming larger feeder dykes that transport the magma rapidly upward to the emplacement sites. The potential speed of ascent and emplacement mean that even very large granitic plutons probably grow in thousands of years. Experimental data on crystallization rates suggest that many of the large crystals observed in granitic rocks could have grown in a matter of hours - certainly in no more than a few tens of years. Geological processes are commonly thought of as slow and continuous, but many are rapid and episodic. Granitic plutonism is of the latter kind.

[rach12]

I thought a long-dead thread worth reviving, to mark a significant paper that has been published recently. It is difficult to pick on a representative post to trigger the response, but I have chosen the above from post #44.

The reference and abstract is below. The key thought that is relevant to this thread is: "Experimental data on crystallization rates suggest that many of the large crystals observed in granitic rocks could have grown in a matter of hours - certainly in no more than a few tens of years. Geological processes are commonly thought of as slow and continuous, but many are rapid and episodic. Granitic plutonism is of the latter kind."

For those who want a quick summary of a tortuous thread, the above is what I was saying, but I was challenged every step of the way!
Well, David, this is certainly an interesting paper; however, rapid crystallization does not necessarily equate to rapid cooling of an entire plutonic body. According to the paper you cited, it would still take 30,000 years to cool (via conductance) a 3 km thick tabular granitic body.

How thick are the largest batholiths? At what depth are they cooling? What is their source or genetic history? What is their chemistry and composition?

If the evidence suggests rapid crystallization of granites, then it will be accepted by the geologic community as possible - or even as the norm, if it comes to that. If I remember correctly, you were challenged because you did not provide the appropriate evidence/literature to support your statements.

I'm happy with the paper you cited above. There's still a lot of speculation, but the theory is interesting and worth persuing. However, it still does not adequately support the YEC position, in my opinion.

[aniso]

Well, David, this is certainly an interesting paper; however, rapid crystallization does not necessarily equate to rapid cooling of an entire plutonic body. According to the paper you cited, it would still take 30,000 years to cool (via conductance) a 3 km thick tabular granitic body.
...
I'm happy with the paper you cited above. There's still a lot of speculation, but the theory is interesting and worth persuing. However, it still does not adequately support the YEC position, in my opinion.

Rach,
What is the citation for the experimental data on rapid crystallization? Is is the one that we went round and round about last year?

[rach12]

Rach,
What is the citation for the experimental data on rapid crystallization? Is is the one that we went round and round about last year?
The one I refer to as 'interesting' is the Clemens paper David cited today (see below), which doesn't actually discuss rapid crystallization much except at the end. I can't remember exactly what it said, but it stated something like a 5mm feldspar could be created as quickly as 1 hour and up to 25 years. I remember thinking that wasn't a very large feldspar - maybe they meant 5 cm? There was no experimental data that I noticed in the Clemens paper.

I'll take a look again at the paper tomorrow to make sure I got it right.

The Clemens paper is really about how large granitic bodies may be emplaced as dikes over a significantly shorter period of time (thousands instead of millions of years) rather than diapirs. I liked the idea. I hadn't read that theory before.



Clemens, J.D., 2005, Granites and granitic magmas: strange phenomena and new perspectives on some old problems, Proceedings of the Geologists' Association, 116, 9-16.

[dtyler]

Well, David, this is certainly an interesting paper; however, rapid crystallization does not necessarily equate to rapid cooling of an entire plutonic body. According to the paper you cited, it would still take 30,000 years to cool (via conductance) a 3 km thick tabular granitic body.
The intense discussion before was all about whether a granitic texture implied long timescales, not whether this equated to rapid cooling.
30K years by conduction is still far shorter than previous estimates. And Diluvialists do not work with the country rock being dry. Water permeates everything to a considerable depth, so convective cooling has to be considered.

How thick are the largest batholiths? At what depth are they cooling? What is their source or genetic history? What is their chemistry and composition?
We all thought the answers to these questions were sorted out many years ago. The new research is changing even the questions we need to ask! As the author writes: "just about everything that was taught as recently as ten years ago about granitic magmatism has been turned on its head."

If the evidence suggests rapid crystallization of granites, then it will be accepted by the geologic community as possible - or even as the norm, if it comes to that. If I remember correctly, you were challenged because you did not provide the appropriate evidence/literature to support your statements.
I still think the literature base I was using was well able to establish the point at issue.

I'm happy with the paper you cited above. There's still a lot of speculation, but the theory is interesting and worth persuing. However, it still does not adequately support the YEC position, in my opinion.
It is not written to support the YEC position, of course. However, the geological context for granite formation, migration, emplacement and solidification is a far better fit with YEC thinking than the older models.

I'm happy to leave this topic now, having flagged up this point. If anyone does want to take things further with me, I'll be on-line again in about two weeks time.

[rach12]

The intense discussion before was all about whether a granitic texture implied long timescales, not whether this equated to rapid cooling.
No, that's not what I remember. We've known crystals can grow rapidly for quite some time, especially under special circumstances. Most of us had a problem with whether the paper had any relevancy to a natural setting and how quickly a large igneous body could cool.


30K years by conduction is still far shorter than previous estimates. And Diluvialists do not work with the country rock being dry. Water permeates everything to a considerable depth, so convective cooling has to be considered.
Umm, David, it doesn't matter in the least to us how long some granitic intrusions take to cool, the point is 30,000 years is still WAY too long for YOU. Larger intrusions take longer and mafic intrusions even longer.


With respect to water, Clemens states:

Relationships between the H2O contents and temperatures
of granitic magmas have shown that magma
genesis occurred during fluid-absent granulite-facies
partial melting of crustal rocks (Clemens & Watkins,
2001). This conclusion is supported by a variety of
mineralogical, thermobarometric, isotopic and experimental
evidence. Field, petrological and experimental
data have shown that common types of crustal rocks
(e.g. metamorphosed pelites, greywackes, tonalites,
andesites and basalts) can all partially melt to leave
granulite-facies residues and broadly granitic melts.
The sorts of fluid-absent reactions involved are similar
to:

• Ms+Pl+Qtz=Als+Kfs+M (in medium-grade metapelites);
• Bt+Pl+Als+Qtz=Grt/Crd+M (in higher-grade metapelites);
• Bt+Pl+Qtz=Opx (+Cpx+Grt) +M (in metagreywackes
and metatonalites);
• Hbl+Qtz=Pl+Opx+Cpx (+Grt) +M (in meta andesites
and metabasalts).

where M represents an H2O-undersaturated granitic
(s. l.) melt. The mineral phases in brackets may or may
not appear, depending on the composition of the
parent rock and the P–T conditions of the melting
reaction.
If there is water present in the vicinity of melts, it will show up in the mineralogies (e.g., hornblende, biotite).



We all thought the answers to these questions were sorted out many years ago. The new research is changing even the questions we need to ask! As the author writes: "just about everything that was taught as recently as ten years ago about granitic magmatism has been turned on its head."
David, every few years something in geology is turned on it's head. Geologists are complacent only because a great majority of us aren't conducting much research on granite genesis, or copper porphyries, or layered intrusions, or carbonate petrology, etc. That's why we go to meeting and conventions - so we can keep up with new developments. So no, I don't think we thought all the answers were sorted out years ago.



It is not written to support the YEC position, of course. However, the geological context for granite formation, migration, emplacement and solidification is a far better fit with YEC thinking than the older models.
Well, yes it does. Why didn't you guys figure this out a long time ago?


I'm happy to leave this topic now, having flagged up this point. If anyone does want to take things further with me, I'll be on-line again in about two weeks time.
Have a nice trip.

[kuboes1831]

David, every few years something in geology is turned on it's head. Geologists are complacent only because a great majority of us aren't conducting much research on granite genesis, or copper porphyries, or layered intrusions, or carbonate petrology, etc. That's why we go to meeting and conventions - so we can keep up with new developments. So no, I don't think we thought all the answers were sorted out years ago.



Well, yes it does. Why didn't you guys figure this out a long time ago?



Have a nice trip.

How about this one? For my undergraduate mapping project I discovered taht the area assigned was a layered basic intrusion and I found the evidence 3 yards from where my professor landed three years earlier. It was on a lake in the NWT so you could only travel by canoe.

[rach12]

How about this one? For my undergraduate mapping project I discovered taht the area assigned was a layered basic intrusion and I found the evidence 3 yards from where my professor landed three years earlier. It was on a lake in the NWT so you could only travel by canoe.
Hey, that's pretty cool! I wonder if it's been explored for base-metals and/or Pt/Pd.

My master's is on a layered intrusion...




I now hate layered intrusions.:brood:

[kuboes1831]

Hey, that's pretty cool! I wonder if it's been explored for base-metals and/or Pt/Pd.

My master's is on a layered intrusion...




I now hate layered intrusions.:brood:

I know Falconbridge at Yellowknife looked at it the following year, but I dont know what they found. They offered me a job on the strength of my u/g thesis but I had just accepted a job - with falconbridge in Africa and was soon to fly to Uganda.

I did geology at Oxford which was full of layered intrusion guys like Wager, Brown (who was nearly refused a visa into the States) and Dave Bell, so it was fun finding one as an undergraduate