Plate tectonics, mountain building, and the Flood

On the The Bible: Accuracy and Inerrancy board a discussion about plate tectonics and the Flood has started as part of another thread. Since this seems to be more of a Geology and the Great Flood kind of topic, I’m starting a thread on it here.From this thread:
http://EvC Forum: Noah's Ark -->EvC Forum: Noah's ArkTranquility Base:
The Earth could have been covered by the ocean prior to the major mountain uplifts. In the Biblical creationist scenario we believe the mountain building (as it is called mainstream) and continental drift occurred during the flood. Hence at some point of the flood year there could have been a 100% covering.The problem here is that you can’t point to a time during earth’s history when there haven’t been mountains. For example, there was a major worldwide episode of mountain building during the late Precambrian (from ~1.2-1.0 billion years ago). There are remnants of event older mountain building events in the earlier parts of the Precambrian. This poses a pretty big problem for your attempt to lump mountain building events and continental drift into a single Flood-related event.Tranquility Base:
Mainstream the largest sea-level changes are explained as due to the tectonic movements that occurred suring continetnal drift and 'sea-floor spreading'. Glacial formation/melting results in lower sea-level changes. So for creaitonists we are left having to explain how to get rapid tectonic effects. We believe that radiodecay was accelerated releasing a lot of heat and sending the continental and sea-floor plates into a runaway state. this has been simulated on computer by a mainstream expert who also happens to believe the flood was a recent event. This runaway effect can yield plate velocities sufficent to generate the observed break-up of Pangea over a matter of years.Based on your comments about Pangea here you want to attribute the break up of Pangea to the flood. So pre-Pangea would be equivalent to pre-Flood and post-Pangea would be equivalent to post-Flood. Your comments also leave me with the impression that you’re stating that Pangea was the original configuration of the continents. In other words, when the continents were created, they were created as Pangea, and they stayed that way until the Flood, when they broke apart to give us the distribution of continents that we see today. If I’ve mischaracterized your views, feel free to correct me.The problem here is that Pangea is not the original configuration of the continents, and plate tectonics did not start with Pangea. Pangea was assembled toward the end of the Paleozoic Era as smaller landmasses collided. The Appalachian Mountains are the result of one of these collisions. So, before Pangea existed, the continents were distributed around the earth. Before that, in the Late Precambrian, the continents were again in a supercontinent configuration (this supercontinent is called Rodinia). The 1.2-1.0 billion year old mountain building event that I mentioned at the start of this post formed as a result of the assembly of this supercontinent, just as the Appalachians formed as a result of the assembly of Pangea. There were likely other supercontinents before Rodinia, and there were certainly pre-Rodinia mountain building events. For example, there are remnants of a 3.0 billion year old continental collision in part of the Canadian Shield (the oldest mountain building event that I know of).The point is that the break up of Pangea wasn’t an unusual event in Earth’s history, the continents have been in motion since at least 3 billion years ago; plates have been colliding and breaking apart throughout Earth’s history. The plates have been in motion since Pangea broke apart too, for example, the Alps and the Himalayas both formed after the breakup of Pangea. So not only were the plates in motion before Pangea was assembled, they’ve been in motion since Pangea broke apart, and they’re still moving. This is another indication that tectonic motion doesn’t represent anything unusual in Earth’s history, as it should if tectonic motion is due to a one-time event like the Flood.The important points are:1) The position that the earth had less topography before the flood can’t be supported because there have been mountain building events throughout Earth’s history.2) Tectonic motion doesn’t represent anything unusual in Earth’s history, it’s been occurring throughout the last 3 billion years of Earth’s history, and it’s occurring today.

Tranquility base:
You're quite right that this puts a severe constrint on when the flood peak occurred. I simply haven't done the research, and am unaware of whether any creationists have done it yet. This work should be done, agreed, but I'm not preprared to accept a blanket statement that there was never a period when the Earth wasn't sufficently flat to be covered by the exisiting water. As usual in this debate there is no simple resource to find the answer because the issue is simply not one of specific interest to mainstream researchers.There's certainly interest in determining the height of mountain ranges in the past. The height of the Himalayas in the past, for example, is an area of active research, as is the uplift of the Colorado plateau. I can think of a couple of ways you could determine paleoelevation. In the case of the Colorado plateau, some researchers looked at variations in the size of vesicles in basalt and inferred the elevation at which the basalt was erupted since the size of the vesicles will be influenced by atmospheric pressure. The reference for the paper is:
Sahagian, Dork; Proussevitch, Alex; Carlson, William. Timing of Colorado Plateau uplift; initial constraints from vesicular basalt-derived paleoelevations, Geology, vol.30, no.9, pp.807-810, Sep 2002.It’s also possible to use stable isotopes, for example oxygen, to determine paleoelevation. Isotopic composition is a function largely of latitude and altitude. If the latitude that a rock formed at is known, then it should be possible to correct for the effects of latitude on the isotopic composition, and figure out the elevation of the rock when it formed. A paper that deals with this is: Chamberlain and Poage. Reconstructing the paleotopography of mountain belts from the isotopic composition of authigenic minerals. Geology, vol. 28, no.2, pp. 115-118.It would be more difficult to determine the paleoelevation of older mountain ranges using isotopes (for example, the Appalachians), because so much of the mountains have been eroded away, but it should be possible to get some information. It would be possible to constrain the latitude using paleomagnetism, and even though the mountains may be eroded, there are still plenty of sediments that were eroded from the mountains preserved. You could determine the elevation of those sediments, and then the mountains would have to be higher than that. I don’t know if this has been done or not, I’m not a specialist in this area, but it should be possible.Even if you can’t precisely determine the paleoelevation, you can get some idea of the size of the mountain belt by determining the amount of displacement along the faults that the uplift of the mountain belt occurred on. In the case of the Appalachian mountains the major faults there accommodated at least 10s of kilometers of displacement, and when you add up the individual displacement of all the faults it’s not hard to get 100s of kilometers of total displacement. Clearly, these were major mountain ranges.Tranquility base:
The ocean basins would also have been shallower than mainstream science predicts. During catastrophic spreading and drift the hot newly created sea-floor would have risen.The present bathymetry of the ocean floor isn’t compatible with a catastrophic event a few thousand years ago. The present bathymetry matches remarkably well the bathymetry expected as a result of conductive cooling of basalt erupted at ridges and the conventional age of the ocean floor.
THE DEPTHS OF THE OCEANSTranquility base:
All possibly true but its certinaty becomes less and less eliable the further we go back. We need to study what the actual heights and timing of all of the montain ranges were.The configuration of Precambrian continents certainly becomes less clear as you go back earlier in Earth’s history, but the fact that there were mountain building events is clear. The point I was trying to make here is that mountain building doesn’t represent anything unusual in Earth’s history.Tranquility base:
We also put down the creation day-3 event (where the land came up out of the sea) to a catastrophic tectonic event, probably also triggered by accelerated radiodecay.An earlier catastrophic event won’t help your position because, as I stated before, tectonic motion isn’t unusual in Earth’s history since plates have been moving throughout that history.

Hello LRP,One of the problems with your idea is that the history of the continents does not begin with Pangea; Pangea formed in the latter part of the Paleozoic Era. I'd be interested to see how you account for the pre-Pangea history of the earth, such as I discussed in the first message in this thread.

I can understand not looking forward to doing an intensive search of the existing literature, but I’m not terribly sympathetic because that’s the first step of any research project. I’ve had to do it myself, and I’d be very surprised if any of my colleagues hadn’t. The data on mountain ranges and their ages are available in the literature, undoubtedly it’d take some leg work to track down all the papers, but I don’t think that’s a valid reason to avoid doing it. It’s certainly preferable to making the unsupported statement that the earth was flatter before the Flood.I also don’t really sympathize with the problem that creationists have to refer to mainstream research. For example, Woodmorappe’s databases were built using mainstream data; Woodmorappe searched through the existing literature to build his database. Perhaps I misunderstood your concern.Tranquility Base:
Interesting but are you sure you aren't missing the more obvious methods such as looking at the deformation of strata etc and determining when it occurred by relative deformaiton vertically? But your method sounds interesting - has it been applied?The structures in the Colorado Plateau have certainly been looked at, but the problem is that the amount of vertical uplift is not equivalent to the height of a feature. Determining the total amount of uplift during a mountain building event isn’t too difficult, and for major events it’s on the order of 10s of kilometers. Finding rocks exhumed from depths of ~30 kilometers is pretty common, but that doesn’t mean that the mountain ranges were 30 kilometers tall. The height of a mountain range is limited by the strength of the rocks that the mountain is composed of. The rocks at the bottom of the mountain are weighed down by the overlying rocks, and if you piled up enough rock, the stress would be too great for the mountain to support. The highest a mountain can be is around 9 kilometers. This means that mountains will grow until the hit that 9 km mark, and after that, instead of continuing to grow vertically, they will start to grow laterally. This is what’s going on with the Himalayas today; India and Asia are still colliding, so mountain-building stresses are still being generated, but the Himalayas can’t get any higher, so they’re expanding laterally. This is why there are active extensional faults in the Himalayas despite the fact that the stresses in that region are compressional. Phrased another way, the rocks aren’t strong enough for the mountains to get any higher, but there’s still deformation going on, and so the rocks have to accommodate that deformation somehow, and they do that is that the mountain belt expands laterally instead of vertically (this process has been given the dramatic name synorogenic collapse).There’s evidence of synorogenic collapse of ancient mountain belts too, in particular I’m thinking of the 1.2-1.0 billion year old mountain belt that I’ve mentioned before. This means then, that these mountains were 9 km high at some point, since they’d have to be that tall in order to cause the collapse. Since these mountains are Precambrian, and since to the best of my knowledge most young earthers would place the Precambrian in the time interval before the Flood, this is a pretty strong indication that the earth wasn’t flatter before the Flood.Tranquility Base:
This all presumes unifromitarianism John (in this case of ocean or perhaps atmospheric temperature). At this point we need to know what has already been reliably done. Then we can prpose schemes for pushing the data.I should have been clearer. I was not trying to claim that the isotopic composition of the atmosphere has always been the same, since it certainly will vary. With that said, the same latitudinal dependence of oxygen isotopic composition that exists today should have existed in the past; in other words, the relative change in oxygen isotopic composition from equator to pole that exists today should have existed in the past since the poles are going to be colder than the equator. It’s actually possible to check and see if the same latitudinal variation in isotopic composition that existed today existed in the past since you can determine the age and the latitude of rocks in the past. For example, you could measure the isotopic composition of shallow marine rocks deposited at different latitudes in the Jurassic, and see if the same dependence on latitude existed then.In the case of the Appalachian mountains the major faults there accommodated at least 10s of kilometers of displacement, and when you add up the individual displacement of all the faults it’s not hard to get 100s of kilometers of total displacement. Clearly, these were major mountain ranges.Sure, so when were they uplifted?The Appalachians were formed in the Paleozoic, as the result of three separate events. The first was in the part of the Ordovician and Silurian Periods (called the Taconic Orogeny), the second was in the Devonian (called the Acadian), and the third was in the Carboniferous (called the Alleghanian).We'll see. You all said that the geo-col was consistent with uniformitarianism. When we go and check we find incredible evidence of high energy events. Correlated paleocurrents half way across continents, vast sorted beds, no modern equivalents (in scope) for most Paleozoic marine strata in N. America and Mesozoic marine strata in Africa etc and fossil graveyards.So we take those claims that 'seafloors look like non-catastrophic flows' with a few grains of salt. If you don’t mind, I’d like to postpone discussing the sedimentological aspects of the geologic record until we’re finished discussing mountains. My preferences would be to either wait for a bit to discuss this, or to start a new thread. What do you think?

LRP:
It seems a little odd to me that if you join up all the present continents it forms a good circular land mass with Jerusalem almost at the centre.Jerusalem didn’t exist at that time, and furthermore most of the rocks in Israel are Mesozoic and formed after Pangea broke up, so most of Israel didn’t exist at that time either.LRP:
Now if mainstream science decrees that there were continents before Pangaea where have they gone to now? Subducted perhaps under a plate? If so whence came the continents that made up Pangaea?I think you’ll find the answer to your question if you think about what happened to the landmasses that made up Pangea. They haven’t been destroyed, they’re just arranged differently.LRP:
I still have not been able to find a convincing theory for the origin of the continents-hence I will hold on to what the Bible says on this problem. So no I cannot account for the pre Pangaea history of the Earth. The idea of a crashed planetissimal as the origin of the first and only supercontinent is simple and logical.An interesting idea, but Pangea wasn’t the first and only supercontinent.

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Originally posted by TrueCreation:
"Why does it matter?"
--With such an ocean bathymetry, you get continental inundation. This also means that Meerts analysis is relatively correct, but his conclusions are not (ie, that the resultant bathymetry is a 'problem').

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Nowhere in Joe's article does he state that the ocean floor was shallow. His point is that if the ocean floor is 6,000 years old then it ought to be a uniform 15 meters deep. Quite clearly the ocean floor isn't 15 meters deep, and so the present bathymetry can't be reconciled with the idea that the ocean floor is 6,000 years old.

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Originally posted by edge:
Second, there is another way of estimating relief for some mountains. Stratovolcanos have a fairly predictable profile that can be seen in some of the ramparts of older volcanic arcs. By projecting them to the known profile we can estimate that some, such as the predecessor of Mt. Lassen, were still on the order of 10-14,000 feet above the current sea level. I can't remember the age or name of this peak, but I'm pretty sure it is quite older than 6000 years (or 4000 years, if the flood supposedly caused the volcanism).

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Estimating the height of ancient stratovolcanos sounds like it would work, but it doesn't sound like it would be widely applicable. It would only work with geologically young stratovolcanos since there would have to be some remnant of the volcano preserved to reconstruct its height. This technique can't be applied to the formation of the Appalachians, for example, even though a volcanic arc was involved with the Taconic Orogeny. It sounds like an intersting idea though.

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Originally posted by TrueCreation:
"Nowhere in Joe's article does he state that the ocean floor was shallow. His point is that if the ocean floor is 6,000 years old then it ought to be a uniform 15 meters deep."
--And you don't call that shallow?

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Yes, I'd call 15 meters shallow, but what I'd call it is irrelevant. The point is that the ocean floor should be 15 meters deep if it formed a few thousand years ago, and since the ocean floor isn't 15 meters deep that's a good indication it didn't form a few thousand years ago.

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"Quite clearly the ocean floor isn't 15 meters deep, and so the present bathymetry can't be reconciled with the idea that the ocean floor is 6,000 years old."
--You should read Meerts source T & S - Geodynamics and find the sections where it explains the principle of isostatic balance. After that, you will see that ocean bathymetry will not stay in such condition.

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I'm familiar with isostasy, and it doesn't eliminate the problem that the ocean floor should presently be 15 meters deep if it formed a few thousand years ago.

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--To make this clearer for you, a mainstream analogy: Eustatic levels in the Cretaceous (80 Ma) were 300m higher than it is today, and water flooded about 40% of the present area of the continents. Such eustatic changes are due to this same process directly associated with Meerts calculations. And Sea levels in the past imply larger values of the mean oceanic heat flux. Were not at that present level are we, bathymetry rebounded.

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I have no problem with the concept that increased spreading rates result in increases in global sea level, but that's also irrelevent to the problem to a young earth point of view caused by the present bathymetry of the oceans. If the spreading rate is high, a lot of hot crust will be generated. Since the crust is young and hot, it has a lower density than older cooler crust, so it rides higher in the mantle than that older, cooler crust; or in other words the ocean depth will be less above the hot, young crust than it will above the old, cool crust. This will displace water on to the continents, but that's still irrelvent to the issue of the present bathymetry of the oceans. If all of the ocean floor was composed of hot,young crust (say a few thousand years old), then it should be riding high on the mantle, and the ocean should be correspondingly shallow, and it isn't.Sure spreading rates have varied in the past, but so what. How does that effect the problem caused by the current bathymetry of the oceans?How do you think isostasy resolves this problem for young earthers? Sure, the depth of the ocean floor will change due to isostasy; as the ocean floor cools, it becomes denser, and rides lower on the mantle, and the ocean will be correspondingly deeper above it.How do you account for the present bathymetry of the ocean floor?

True Creation,

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True Creation:
--I don't think you are, because if you were, you would see that it doesn't stay like that. Its either that or the relationship between density and temperature in this scenario which you are missing.

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Of course the depth of the ocean floor changes as the crust cools, that was the point of Joe Meert's article, and I've explained that myself several times in this thread. Of course the ocean floor doesn't stay as hot as it was when it form, I've been over that too. However, if the ocean floor has only been cooling for a few thousand years, then it should only have cooled enough to have a depth of 15 meters. Nothing you've written to this point has addressed this problem.Letting the ocean cool for a couple thousand years won't do it; you'll wind up with an ocean that 15 meters deep. Appealing to isostasy won't do it; you'll wind up with ocean floor that rides on the mantle at a level that results in an ocean that's 15 meters deep. Nothing you've written has explained why this shouldn't be the case.To this point, your answers have been frustratingly low on information. I'd appreciate it if you take the time to write a longer more detailed post explaining your idea.

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Originally posted by Tranquility Base:
John S

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I'm happy to psotpone sedemintological aspects (they've been discussed a lot in the past here you realise of course).

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Thank you. I do realize that this topic has been discussed before. I'll try to go over the existing threads so I can get a feel for the previous discussions.

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I agree with everything you've written. I'll just point out that you are yet to come up with any hard data on heights. Your cited 9km is really a theoretical/extrapolated expectation. In our sceanrio these warpings and uplifts happened catastrophically simultaneously with huge flood sruges. So the uplifts could have occurred shattering rock that was catastrophically carried away. It may never have reached the heights you understandably expect even though the left over warping is compatible with such heigths.

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There are a couple of points that I think are important. The first is that large mountain ranges existed in the Precambrian, which means that large mountains existed before the Flood. This makes it difficult to claim that the earth was smooth before the Flood.The second is that major mountain ranges both in the Precambrian and after show indications of synorogenic collapse. This means that they had to be tall enough to induce synorogenic collapse, and this means that they could have been up to ~9 km tall. Just for argument's sake, let's say that figure is too large by half, making the maximum height of mountains 4.5 km (or ~15,000 feet).

True Creation,Thanks for the link, I appreciate it. If you have any more thoughts about how the bathymetry of the ocean floor can be explained, I'd appreciate it if you'd post them here.

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Originally posted by Tranquility Base:
As an excesize, can someone here post a clear summary of the evidence that a Paleozoic mountain chain was entirely uplifted prior to the Mesozoic being deposited? Let us look carefully at the actual data. In our sceanrio the uplift could have been occurring gradually during the flood with its peak being achieved only after the 100% covering. Can we really identify the height prior to the Mesozoic or is it actaully a lot of guess work?

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edge has already mentioned the Appalachian mountains (and with that I'm including the equivalent mountain belts in the Europe, Greenland, and Africa). Another I can think of is the Ancestral Rocky Mountain orogeny in western North America. This event occurred from the Pennsylvanian to the Permian. This event was finished by the start of the Triassic, when the area where there had previously been mountains was covered by Triassic sediments.The Antler Orogeny in western North America is another example. It began in the Devonian and was finished by the end of the Pennsylvanian.