Earthquake activity folded the rock layers. Volcanic eruptions destroyed a rock layer. Erosion removed several layers of rock. Weathering changed the layering of the rocks.
I gave my students this multiple choice question: In studying layers of rock sediment, a geologist found an area where older rock was layered on top of younger rock. Which best explains how this occurred?

Only one answer is correct among these 4 choices:
- Earthquake activity folded the rock layers.
- Volcanic eruptions destroyed a rock layer.
- Erosion removed several layers of rock.
- Weathering changed the layering of the rocks.

Could you tell me which one is correct?

Earthquake activity folded the rock layers.