Question

What are the three categories of unconformities?

1) Disconformities
2) Nonconformities
3) Angular unconformities
4) Non-unconformities

Answer 1

The three categories of unconformities are disconformities, nonconformities, and angular unconformities.

Step-by-step explanation:

The three categories of unconformities are:

1. Disconformities: These form when there is an erosional surface between two horizontal layers of sedimentary rock. The rocks below the unconformity are older than the ones above. Disconformities typically occur when sea level lowers, exposes the rocks, and allows erosion to occur before sea level rises again and new layers of sedimentary rock are deposited.
2. Nonconformities: Nonconformities form when igneous or metamorphic bedrock is eroded, and horizontal layers of sedimentary rock are deposited directly on top of it. This creates an unconformity where the bedrock meets the sedimentary rock.
3. Angular unconformities: These occur when horizontal layers of sedimentary rock lie on top of tilted or folded layers of sedimentary rock. The angle between the younger, horizontal layers and the older, tilted layers represents the unconformity.