Relative Dating practice

Front

What is the law of crosscutting?

Back

The law of crosscutting states that a geological feature (like a fault or intrusion) is younger than any rock layer it cuts through.

Front

How does the law of crosscutting explain the age of a fault?

Back

The fault is younger than the rocks it cuts through.

Front

What is an intrusion in geology?

Back

An intrusion is a body of igneous rock that forms when magma cools and solidifies beneath the Earth's surface.

Front

What is the difference between a fault and an intrusion?

Back

A fault is a fracture in the Earth's crust where rocks have moved past each other, while an intrusion is a mass of igneous rock that has intruded into pre-existing rock.

Front

What does the term 'inclusion' mean in geology?

Back

Inclusion refers to fragments of one rock type that are contained within another rock type, indicating that the included rock is older.

Front

What is an unconformity?

Back

An unconformity is a surface that represents a gap in the geological record, where rock layers have been eroded or not deposited for a period of time.

Front

How do you determine the relative ages of rock layers?

Back

Relative ages can be determined using principles such as superposition, original horizontality, and crosscutting relationships.

Front

What is the principle of superposition?

Back

The principle of superposition states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest layers are at the top.

Front

What is the significance of the order of rock layers?

Back

The order of rock layers helps geologists understand the history of the Earth and the relative ages of the rocks.

Front

How can you identify the oldest layer in a sequence of rock layers?

Back

The oldest layer is typically the bottom layer in an undisturbed sequence, according to the principle of superposition.