A series of Questions for our Geologists.

If you want an idea how the lines formed just look at the area NW of PHiladelphia from about 200 miles. it shows fairly well, the geometry of the folds.

we'll get up there edge, but first I'd like to hammer this point home.

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Aslan is not a Tame Lion

I apologize, I cannot extract what this point is. Could you summarize?

Well, if we look at an aerial view of the area NW of Birmingham, we see what looks like folded fans of paper. They extend in a general NW direction. How were they formed?People have said they were formed during a collision when the continents collided to form Gondwana. If that's the case, let's examine that theory in a little more detail.

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Aslan is not a Tame Lion

Thank you for the summary.I have to ask though: what more can be said about it than "landmass A has been thrust into landmass B"?This sort of thrusting is observable all over the world in locations where the land has been measured to move anywhere from 1 to 10 cm a year.I briefly browsed Google earth and found some prominent folding similar to these folds in Al.At Pakistan and Afghanistan, the absolute velocity of the Arabian plate has been measured at 4.65 cm/yr moving into the Eurasian plate, which has been measured moving at less than 1cm/yr.At the northern tip of Myanmar (south of China), the Indian plate is forcefully pushing into the Eurasian plate as well, at a brisk pace of 6 cm/yr. This is pushing the land upwards into those folds we know as the Himalayas.And what does this brisk pace of the indian plate tell us? That the hills and valleys it creates will be relatively new, in geological terms. Therefore they will have been exposed to less wind and water erosion over time, which would make them very rocky. And yes, the Himalayas are indeed rocky.Now about the thrusting in Knoxville. If you look at google earth, you'll see that the landscape here is softer and not nearly as rocky as in the Himalayas, even though we have a large amount of lateral displacement here, like at the Indian plate. So why aren't there Himalayan-style rocky mountains in Knoxville? There probably were at one time. But they've had alot of time to be smoothed out by water running down the sides of the hills and by the wind blowing topsoil around.The fact that we have the North American Plate and not a bunch of smaller plates agrees with this.So....what more can be said?

What evidence is there to support that? How do we know there were mountains there at any time?

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Aslan is not a Tame Lion

Off the top of my head; there are traces of those mountains across the continent. It seems there were major rivers draining west from them and some sediments are attributed to that.I suspect that there is a lot more geophysical data than that but haven't a clue.Oh boy I get to use AIG as a reference LOL Appalachian Mountain Siliciclastics Source for Navajo Sandstone | Answers in Genesis
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Page Not Found | Yale UniversityThis message has been edited by NosyNed, 02-04-2006 11:56 PM

quote:

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What evidence is there to support [mountains in the American east]?

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Don't take my word as proposed fact. That statement came from my observation of the satellite imagery over Knoxville and that's all.
I think there were probably hills that were larger and rockier than they are now.What I am really trying to get across is that erosion exists. Do you agree with this?

The second reference was very good, but neither really addressed the main question. W may know that there is sand in the west that came from the east, but is there any evidence that there really were mountains there in the first place.Remember, we are talking about a very specific area, stretching from Birminham, AL up to Knoxville, TN.

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Aslan is not a Tame Lion

Sand doesn't flow up hill. If it came from far east and is in the west it needed some help.There is a LOT of it. That implies a lot eroded too.This message has been edited by NosyNed, 02-05-2006 12:24 AM

Okay.What we find in the west is sand and sandstone. Sand is pretty easy to move around. Sandstone also erodes fairly quickly.So, is there any evidence that what we see is not just sand that was moved around, likely by a great flood?

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Aslan is not a Tame Lion

I am not going to spend much time with this. We can tell the kinematics of the event by the vergence of folding. We can also see the uplifted parts of the crust in the cores of the mountain ranges. We can also see the metamorphic assemblages that suggest deep burial, but they are now at the surface. As Ned notes, we can also see sedimentary patterns and unconformities that suggest uplift above base level. If there is another explanation for these and other data, I'd love to hear it.

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sand that was moved around, likely by a great flood

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At the risk of becoming a bit off-topic, floods cannot erode dozens of feet of stone and deposit them elsewhere. Even a flashflood over loose sand will not do what was described. I wish people would stop implying that one flood is responsible for all sedimentary rock on earth. That's just silly.Best case scenario: when water covered the earth, it flowed strongly in random directions over an earth made solely of sandstone. You would still not get these results.[edit] And remember! Noah's flood lasted a month. A month! Go observe the strongest, most violent river that exists today and tell me how many feet it sinks into the ground in a month.This message has been edited by Drewsky, 02-05-2006 02:54 AM

There is a possible flaw in thinking here. The sediments laid down have become sandstone. That doesn't mean the source of the sand was sandstone or easily eroded. (might be might not be).

because I think that it might be very important to help me and others understand. What does that mean in english? Great. Can you explain that just a little more for us? This is great. So what exactly are those assemblages and can just anyone recognize them?

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Aslan is not a Tame Lion