A student observes rock layers that are folded and appear to be scratched. Select all of the geologic forces that might have caused this. A plate tectonics B glacial advance C magnetic reversal D seafood spreading

Answer: A plate tectonics

B glacial advance

Both plate tectonics and glacial advance and extensive geological phenomena that have the power to affect rock layers in the observed manner. Through the movement of the tectonic plates, rock layers can not only be folded, but also created or destroyed.

The enormous mass of ice contained within glaciers with a thickness of 3 to 4 km, is more than enough to warp and scratch rock layers. They have also moved large amounts of rock many kilometers from their original location.