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Geology, Palaeontology & Archaeology / How reliable are present rock features as a guide to past geology?
« on: 08/03/2014 05:13:46 »
I was told once (I think it was on this forum) that today's topology has nothing to do with past topology. I took that to mean that things do not erode and expose previous landforms as they were before they were covered.
I was also told that there is a missing 5 miles of sediment in the Carolina piedmont and coastal plain.
If that is so, then why does it seriously appear that the coastal plain and the border area with the piedmont is ocean bottom and a shore line? If you follow 250ft asl it looks like it was a beach. It looks just like either the ocean lost 250ft of water or the area was raised up that amount.
I mean, how is it possible that erosion would so perfectly erode away all of that dirt and rock and leave such a perfect representation of the previous ocean bottom? Could it be the ocean was higher recently (geologically speaking) and the created landform is yet to erode?
Or could the area be subject to some sort of tectonic uplift? I have read that there was a period some 5 million years ago when the Uwharries experienced uplift and another 25 million years ago for the Appalachians. Could whatever event that caused the uplift have caused the sea bed to raise 250ft?
Or is the whole "65 million year old sea bed eroded out of 5 miles of sediments" thing orthodoxy and set in stone so to speak?
I was also told that there is a missing 5 miles of sediment in the Carolina piedmont and coastal plain.
If that is so, then why does it seriously appear that the coastal plain and the border area with the piedmont is ocean bottom and a shore line? If you follow 250ft asl it looks like it was a beach. It looks just like either the ocean lost 250ft of water or the area was raised up that amount.
I mean, how is it possible that erosion would so perfectly erode away all of that dirt and rock and leave such a perfect representation of the previous ocean bottom? Could it be the ocean was higher recently (geologically speaking) and the created landform is yet to erode?
Or could the area be subject to some sort of tectonic uplift? I have read that there was a period some 5 million years ago when the Uwharries experienced uplift and another 25 million years ago for the Appalachians. Could whatever event that caused the uplift have caused the sea bed to raise 250ft?
Or is the whole "65 million year old sea bed eroded out of 5 miles of sediments" thing orthodoxy and set in stone so to speak?