Front

How does sedimentary rock usually form?

Back

Sedimentary rock usually forms horizontally.

Front

What are traces or remains of organisms that lived long ago called?

Back

Fossils.

Front

What do scientists study to learn about the history of life and past environments on Earth?

Back

Fossil Record.

Front

What is the youngest layer in a rock outcrop?

Back

The youngest layer is the topmost layer, often labeled as A.

Front

What is the term for the number of years that have passed since a rock formed?

Back

Absolute age.

Front

What principle states that in undisturbed layers of rock, the oldest layers are at the bottom?

Back

Law of Superposition.

Front

What is an unconformity in geology?

Back

An unconformity is a gap in the geological record where rock layers have been eroded or not deposited.

Front

What is the difference between relative age and absolute age?

Back

Relative age is the age of a rock compared to other rocks, while absolute age is the actual number of years since the rock formed.

Front

What is an index fossil?

Back

An index fossil is a fossil that is used to define and identify a particular time period in the geological time scale.

Front

What does the term 'fossilization' refer to?

Back

Fossilization is the process by which organic material is preserved as a fossil.