What are these geologic formations

[masraum]

Originally Posted by ckissick

I can expand on this.

This question would have been right out of one of my geology midterms back in the early Holocene at UCSB. The essay answer would be longer than what I will bore you with here.

When the early Appalachians were formed during the collision between Africa and North America, the sedimentary rocks were folded and uplifted to mountains that would have looked a lot like the Alps today. Then the two continents moved apart, ending the episode of uplift.

The large mountain chain then eroded. The contorted layers of sedimentary rock eroded at different rates. Harder sandstone layers stand out. The folding created plunging anticlines and synclines. A plunging fold is a fold whose fold-axis is not horizontal. When you erode plunging folds, you end up with U-shaped features in map view. This is what you've got here.

Cool info, thanks tons!

[RWebb]

ah... but!

why are the ridges curved like that?

[masraum]

Originally Posted by RWebb

ah... but!

why are the ridges curved like that?

They're old and starting to sag due to age. Another couple of years and they'll have sagged down to the equator.