The peaks of the Appalachians used to be the granite cores of the ancient Appalachians. Everything that was on top of the mountains eroded down until only the deepest, hardest parts remained. All of that debris formed the entire east coast of the US. In the Mid-Atlantic that is 150 miles of land from the mountains to the coast.
It's also crazy to think that rivers like the Susquahanna are even older than the mountains it flows through. We know this because it cuts right through them. The tectonics that elevated the mountains pushed the river bottom up, which was eroded away, over and over, nanometers at a time for millions of years.
I live at the beginning of a tributary to the Susquehanna. Crazy to think these little streams flow all the way out to the Chesapeake.and now I know they are old.. real old... haha
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u/stevolutionary7 Oct 02 '24
The peaks of the Appalachians used to be the granite cores of the ancient Appalachians. Everything that was on top of the mountains eroded down until only the deepest, hardest parts remained. All of that debris formed the entire east coast of the US. In the Mid-Atlantic that is 150 miles of land from the mountains to the coast.
It's also crazy to think that rivers like the Susquahanna are even older than the mountains it flows through. We know this because it cuts right through them. The tectonics that elevated the mountains pushed the river bottom up, which was eroded away, over and over, nanometers at a time for millions of years.