Understanding Unconformities in Geology

What is an unconformity in geological terms?

• A type of rock formation

• A surface of contact between rock layers representing missing time

• A type of fossil

• A volcanic eruption

Which type of unconformity is formed when sedimentary rocks are deposited over igneous rocks?

• Disconformity

• Conformity

• Angular unconformity

• Nonconformity

How is an angular unconformity formed?

• By volcanic activity

• By horizontal layers of rock being eroded

• By sedimentary rocks being deposited over igneous rocks

• By tilted rocks being eroded and then covered by new sediment

Why can a disconformity be difficult to recognize in the field?

• Because it involves tilted layers

• Because both layers are horizontal and have the same orientation

• Because it is always covered by vegetation

• Because it only occurs underwater

What geological events can unconformities help geologists to discover?

• Formation of new minerals

• Earthquakes

• Meteor impacts

• Episodes of volcanism, uplift, erosion, and deposition