Plate Techtonics!

[Nyril]

Several years ago (more then one, less then ten thousand) the idea that the Earth was not the center of the Universe was high in the ranks of things we argued about. Neatly behind that would be the age of the Universe, age of the Earth, the Earth goes around the sun, Earth is flat, etc. In time, a number of these ideas were accepted by pretty much everyone. By that I mean that I doubt even YEC will argue the point that the Earth is the center of the Universe and in addition to being flat also has the sun and everything else revolve around it.

On that line of thinking, I'd like to ask what you think of plate tectonics in that regard. It isn't brought up much on these boards, but because it neatly explains how we get fossils and strata on opposite sides of the Ocean all neatly lined up (such as the shore between Africa and South America), I imagine there must be some controversy surrounding it.

So, plate tectonics, is it like the Earth being round, or closer to evolution in terms of the amount of public debate surrounding it?

[MagusYanam]

However, no evidence have been presented yet on plate tectonics on this forum.

There is plenty to be had, and a representative fraction of it has been presented. Here we have the observed, empirical facts (Sutur's Island, the Ring of Fire, Himalaya) that indicate directly that the vast majority of seismic activity occurs along boundaries in the crust we supporters of the tectonic model like to call 'fault lines'. These fault lines clearly mark plates of crust - clearly enough, at any rate, for them to bear names and to be marked on a map issued by the National Geographic Society. The plate boundaries exist. Empirical fact. Therefore, it is not so hard to come to the conclusion that plates themselves do also.

Add to this Nyril's list, the practical, not to mention trustworthy, applications of tectonic theory (such as earthquake prediction) and the JOIDES / DSDP research, and the tectonic model looks to me to be pretty secure as a description of seismic activity, even though the particulars are still being ironed out (which is why I didn't give it the 'pure fact' vote).

Standing on its own, it would seem to be indicative of the tectonic model. The only reason I tried to address the flood model here was because that was the test you seem to be applying to the evidence. I hate being repetitive, but it appears I must - it is immaterial whether or not the evidence also supports the flood model. One could well argue that all seismic activity is caused by a giant catfish turning in its sleep beneath the earth's surface and the evidence could support this model if one wanted it to, but that is beside the point. The tectonic model is sufficient for the evidence, but is also elegant - no bells and whistles attached, no vested interest. It is simplest to think that plate boundaries behave the way they do because the lithosphere is fractured and the 'pieces' are 'afloat' on the asthenosphere. That's why we can see things like portions of these plates of lithosphere being submerged beneath others (subduction, Nazca Plate and South America, for example, the Andes being a result) or ramming together (India and Eurasia, Himalaya) or sliding past each other (strike slip faults like San Andreas in California) or moving apart (the Mid-Atlantic Ridge and Sutur's Island).

By the way, I fail to see how the post just preceding mine was useful. Perhaps YEC could try participating constructively in this discussion?

[Nyril]

Oh...I forgot, things happened yesteryears just the same as they happen today.

Because we see the continents creeping today..It's obvious they were also creeping just after and during the flood...riiiiight?

We can look at the continents, we can look at the strata we find on other continents, we can look at magnetic cores taken from iron, and we can say with absolute certainty that a continent which was moving this year was moving last year, the year before, the year before, and so forth for several hundred million years.

As for your comment itself, what does a flood have to do with plate tectonics? Does your point even approach an area in which I could grant you the status of being on topic?

[micatala]

OK, I had wanted to defer on talking about plate tectonics until the Questions for Uniformitarianists have been satisfactorily addressed. But, since this thread has been started...

Nyril wrote:

Because it neatly explains how we get fossils and strata on opposite sides of the Ocean all neatly lined up (such as the shore between Africa and South America), I imagine there must be some controversy surrounding it.

Otseng:

Actually, I believe the Global Flood Model fits better.


Since 2 people so far have voted that plate tectonics is a virtual fact, please present your evidence to back your claims. I eagerly await to see how people can support plate tectonics as a virtual fact.


This thread is not for pitting plate tectonics against the flood. The flood threads are quite lengthy and there is no need to reiterate them here. However, no evidence have been presented yet on plate tectonics on this forum. This thread is yalls chance to prove your case.

IT seems to me that evidence has been presented by Magus and Nyril.

I also think it is worth referring to the Trusting the Experts http://www.debatingchristianity.com/for ... php?t=1433 thread. (Pardon my not figuring out linking yet ). I know you want the forum debaters to produce the evidence, but I think the fact that the overwhelming majority of geologists support the plate techtonic theory is legitimate and compelling evidence in itself.

[Jose]

I agree with micatala that the evidence has been presented by MagusYanam and Nyril. I will, however, offer a bit of a story.

In 1964 or so, my sister was briefly engaged to a geologist at Caltech, who was studying the San Andreas. One of their methods way back then was to set up markers, and measure distances between them at various intervals. Another was to align structures (strata, cracks, mountains) that were on opposite sides of the fault. From this, it was possible to determine the rate of movement, the direction of movement, and the time period over which movement has occurred. As a mere kid, I thought this was pretty cool.

Now that we have satellites and much more sophisticated measuring devices, we can measure the rates and directions of movement of the plates. It's interesting--if you calculate, based on the rate of movement, the time at which North America could have separated from Asia, you get just what geologists suggest.

In other words, the plates are moving. Where they crash into each other, seismic evidence tells us which is being subducted below the other. Where they spread apart, we have ocean ridges with active magma extrusion. This kinda looks like plate tectonics is happening.

Now, YEC, you make a valid point. We see that it's happening now; how can we tell that it happened long ago? Well, here's an interesting view of it:

Directions and of rates of movement suggest that Australia split from Pangaea first, then the Indian Plate separated and Gondwanaland (Africa and South America) separated from Laurasia (Eurasia and North America). Somewhat later, Africa separated from South America. Last, Eurasia separated from North America and India crashed into Eurasia.

OK..what implications does this have for the plants and animals on these continents? If we just consider microevolution, which you agree occurs, we predict that Australian life should be most different, because it has been separated from all other continents for the longest time. We expect African and South American life to be quite different from each other, but more similar than to Australian life. By contrast, we expect European and North American life to be most similar among these comparisons. (We can't make predictions about Africa and Eurasia without knowing something about the climate in the region that is currrently the Sahara and Saudi Arabian deserts, which could be a barrier to migration if dry, or no barrier if wet).

Look at that: we find kangaroos, koalas, kookaburras, dingoes, eucalypts, auracarias, and such only in Australia and not in the Americas, Africa, or Eurasia. These life forms are the most different, just as predicted if the plates moved as current calculations indicate. African and South American creatures are not so different, since there are monkeys in both regions, camel-like animals in both regions (camels and dromedaries vs llamas, alpacas, and vicunas), but these aren't exactly identical. By contrast, the northern hemisphere has remarkable similarities--deer are deer in Europe and N. America, albeit different species; there are similar types of pine trees, wild cherries, larch and spruce; both have wolves.

There are other geological correlates as well, but I find it particularly amusing to bounce geological and evolutionary observations off of each other. They correlate so nicely--and provide completely independent types of evidence.

[I agree with otseng that this is not the place to say "how can your flood explain that?" But, I will point out that the flood model invokes continent movement during or immediately after the flood, with no mechanism to cause continued, slow movements today. However, if we think of the earth as a giant bowl of porridge, with the interior burbling slowly as it moves a thin scum around on the surface, we get a pretty good image of what geological data seem to tell us is there.]

[otseng]

Hmm, I didn't realize that so many people subscribed to plate tectonics. According to the poll, the number of supporters is up to 9, whereas I'm the only one dissenting. Guess I've got a lot of work cut out for me.

First, let's look at one typical illustration of how supposedly the plates moved - Color coded continents.

That is a lot of geological movement over a period 620 million years. Entire continents have moved over a vast amount of distance. One would expect that geological changes of such magnitude would have evidence of it in the rock record through folds or faults or any other evidence of rock movement. That is, one would expect that each layer in which the plates have moved would exhibit some evidence of earth movement. However, rather than this being the rule, it is by far the exception. Stratas are all generally parallel to each other with little to no evidence of any faults or folds between each successive layer.

If entire continents have been moving over a period of over 600 million years up to now, why are sedimentary layers for each time period parallel to each other with little evidence of any faulting or folding?





QED posted this nice picture:

[John S]

If entire continents have been moving over a period of over 600 million years up to now, why are sedimentary layers for each time period parallel to each other with little evidence of any faulting or folding?

I mentioned this in the thread "Questions for Uniformitarianists", but I want to caution again about making generalizations about the rock record based on a single area.

The answer to your question is that rocks are deformed where plates collided, and similarly, they're not deformed away from those areas. As a modern example the ongoing collision between Asia and India produced the Himilayas - the parts of India and Asia that collided are deformed, they areas away from that collision aren't.

You see the same thing with ancient plate motions - deformation occurs where plates collided; move away from the collision zone and the rocks aren't deformed.

Here are two pictures of deformation in Paleozoic rocks in the Appalachian mountains:

http://www.talkorigins.org/faqs/lewis/appalachian1.jpg

http://visibleearth.nasa.gov/view_rec.php?vev1id=1046

Rocks of the same age that are further away from the collision aren't deformed. Does that lack of deformation mean that plates didn't collide and form the Appalachians? No - it just means that those undeformed rocks weren't involved in the collision.

[John S]

I wanted to point out that in the thread "Questions for Uniformitarianists" I've mentioned many different mountain building events (orogenies) that occurred at different times in geologic history in different geographic areas. Those orogonies were caused by the plate collisions.

[otseng]

I mentioned this in the thread "Questions for Uniformitarianists", but I want to caution again about making generalizations about the rock record based on a single area.

I'm not sure what you mean by a "single area". I presented pictures from 3 different areas. And by no means are the pictures unique. Such illustrations of parallel strata are abundant.

Here are two pictures of deformation in Paleozoic rocks in the Appalachian mountains:

The pictures you presented are pictures of the surface, not a cross-sectional picture. So, they do not quite address my argument. Some better pictures that would address my argument are cross-sectional pictures that show faults/folds between stratum.

Rocks of the same age that are further away from the collision aren't deformed. Does that lack of deformation mean that plates didn't collide and form the Appalachians? No - it just means that those undeformed rocks weren't involved in the collision.

I agree with your statements, but I fail to see how they address my argument.

Some more questions about plate tectonics. When the plates move, where exactly is it moving? Where are the lines of demarcation of the plates?

I wanted to point out that in the thread "Questions for Uniformitarianists" I've mentioned many different mountain building events (orogenies) that occurred at different times in geologic history in different geographic areas. Those orogonies were caused by the plate collisions.

(From the Q's for U's thread)

I mentioned several different orogenies (mountain building events). I’ll use two of them, the Late Precambrian Grenville orogeny and the Early Paleozoic Antler orogeny as examples.

Again, what would be illustrative are the cross sectional analysis of mountains.

Here is a paper on the Pink Mountain Anticline. In figure 4, it diagrams the cross section of the mountain. All of the layers are parallel to each other. This would indicate that the mountain was formed after all the layers were laid down. Also, the faults lines run all the way to the top of the layers. This is consistent with catastrophism and not consistent with uniformitarianism as I have argued here.

Here is a cross sectional diagram of the Swiss Alps. Again, it appears that the mountain was formed after all the layers were laid down.

Here is another illustration of the Swiss Alps to demonstrate that gradual compression cannot have occurred while all the layers were being deposited. But, the compression event must've happened after all the sedimentary layers were formed.

[YEC]

Oh...I forgot, things happened yesteryears just the same as they happen today.

Because we see the continents creeping today..It's obvious they were also creeping just after and during the flood...riiiiight?

We can look at the continents, we can look at the strata we find on other continents, we can look at magnetic cores taken from iron, and we can say with absolute certainty that a continent which was moving this year was moving last year, the year before, the year before, and so forth for several hundred million years.

You can say with absolute confidence? I don't think so my evo minded friend. After all if this confident was so high...then why can all the other models looking at the continents, strata (especially folded) and magnetic cores be interpreted otherwise? But then again you seem to be pretty biased when it comes to your close EDITED so otseng doesn't get the wrong idea.

As for your comment itself, what does a flood have to do with plate tectonics? Does your point even approach an area in which I could grant you the status of being on topic?

I honestly can't believe you just asked that question...how many years have you been doing this forum stuff? And now you act like you don't know????? Please cut me a break fellow. Don't be so EDITED so otseng doesn't get the wrong idea.

[Jose]

That is a lot of geological movement over a period 620 million years. Entire continents have moved over a vast amount of distance.

Yeah...but at measured rates--say, 4cm/year--that's enough to move some 15,656 miles, or roughly 62% of the way around the earth. The can't get that far, of course, because they crash into each other again only half-way around. It's a large distance, all right, but it's also a long time.

I mentioned this in the thread "Questions for Uniformitarianists", but I want to caution again about making generalizations about the rock record based on a single area.

I'm not sure what you mean by a "single area". I presented pictures from 3 different areas. And by no means are the pictures unique. Such illustrations of parallel stratas are abundant.

I'll see if John provides the same answer as mine (hee hee). One cannot generalize a single mechanism from one example, or from three examples, or from a hundred examples. Rather, one must look at as many examples as possible, and then try to figure out what series of forces can have caused the series of different--but similar--observations. We cannot say "these 6 examples of horizontal strata prove that all strata are horizontal" or "these 12 examples of folded strata prove that all strata are folded." If we look at all 18 of those examples, we have a more complex problem: why are some strata horizontal, and some folded? In general, the horizontal strata are not at plate boundaries, or over volcanic intrusions. In general, the folded strata are near plate boundaries.

California is a good example of messy geology (see John McPhee's Assembling California). It is built from several plates crashing into North America, resulting in lots of folded strata, as illustrated here.

Here are two pictures of deformation in Paleozoic rocks in the Appalachian mountains:

The pictures you presented are pictures of the surface, not a cross-sectional picture. So, they do not quite address my argument. Some better pictures that would address my argument are cross-sectional pictures that show faults/folds between stratas.

Cross-sectional pictures are best seen in cliff faces, or where the strata have been folded, then tilted, then eroded to produce a cross-section. A drawing is an interpretation, and is therefore less valuable. Remember also the good views of the strata of the Vishnu Schist, which are vertical, not horizontal.

Rocks of the same age that are further away from the collision aren't deformed. Does that lack of deformation mean that plates didn't collide and form the Appalachians? No - it just means that those undeformed rocks weren't involved in the collision.

I agree with your statements, but I fail to see how they address my argument.

We observe various kinds of strata, including those that are horizontal (including the Interior Low Plateaus, among which I live). Why are they horizontal? The obvious, simple, correct, but kinda dumb answer is: because they weren't tilted or folded.

Some more questions about plate tectonics. When the plates move, where exactly is it moving? Where are the lines of demarcation of the plates?

As illustrated by the USGS, the plates are moving away from the mid-ocean ridges, which are the spreading centers--undersea volcanic rifts, if you will. Here and here are a couple of sites that indicate the plate boundaries. From the code of arrowheads and little lines, it is possible to infer the directions of movement.

Remember, this has all been measured.

I wanted to point out that in the thread "Questions for Uniformitarianists" I've mentioned many different mountain building events (orogenies) that occurred at different times in geologic history in different geographic areas. Those orogonies were caused by the plate collisions.

(From the Q's for U's thread)

I mentioned several different orogenies (mountain building events). I’ll use two of them, the Late Precambrian Grenville orogeny and the Early Paleozoic Antler orogeny as examples.

Again, what would be illustrative are the cross sectional analysis of mountains.

How about the Bullfrog fold, visible in a roadcut on Utah Highway 276, SW of Mt. Ellsworth, near Bullfrog, Utah? It's a real cross section, cut by highway engineers. It obviously folded after the sediments had been lain down. In this case, it's not obvious that it's a plate crash that caused it (or is it, John?); in the Henry Mountains, granitic intrusions lifted up the overlying sedimentary rock. This is one of the bends from one of the associated faults.

Here is a paper on the Pink Mountain Anticline. In figure 4, it diagrams the cross section of the mountain. All of the layers are parallel to each other. This would indicate that the mountain was formed after all the layers were laid down. Also, the faults lines run all the way to the top of the layers. This is consistent with catastrophism and not consistent with uniformitarianism as I have argued here.

I don't see how this is inconsistent with "uniformitarianism," unless by this term you mean something different from traditional geology. The sediments were deposited, converted to rock, and then the mountains formed--by traditional "uniformitarian" mechanisms. There is no conflict with either model.

Here is a cross sectional diagram of the Swiss Alps. Again, it appears that the mountain was formed after all the layers were laid down.

Here is another illustration of the Swiss Alps to demonstrate that gradual compression cannot have occurred while all the layers were being deposited. But, the compression event must've happened after all the sedimentary layers were formed.

I guess I'm missing something here...how do these illustrations argue against normal geology? The difference between "uni" models and "flood" models is the time frame. The "flood" model proposes that everything happened really fast when the sediments were still soft. The "uni" models suggest that the folding occurred slowly, as earthquakes occurred in the normal ways that we can observe.