Relative Dating Review

Front

What is relative dating?

Back

Relative dating is a method used to determine the age of rocks and fossils in relation to one another, without determining their exact age.

Front

What does the principle of superposition state?

Back

In an undeformed sequence of sedimentary rocks, the oldest layers are at the bottom and the youngest layers are at the top.

Front

What is an unconformity?

Back

An unconformity is a surface that represents a gap in the geological record, indicating that sediment was not deposited or that erosion occurred.

Front

What is the principle of lateral continuity?

Back

The principle of lateral continuity states that layers of sediment initially extend laterally in all directions; they may be interrupted by erosion or other geological processes.

Front

What are inclusions in geology?

Back

Inclusions are fragments of one rock type that are contained within another rock type, indicating that the rock containing the inclusions is younger.

Front

What is the significance of crosscutting relationships?

Back

The principle of crosscutting relationships states that a geological feature (like a fault or intrusion) that cuts through another is younger than the feature it cuts.

Front

What type of rock is formed from cooled magma?

Back

Igneous rock is formed from the cooling and solidification of magma or lava.

Front

What is the difference between igneous intrusion and extrusion?

Back

Igneous intrusion occurs when magma pushes into pre-existing rock layers, while extrusion occurs when lava erupts onto the Earth's surface.

Front

What is the oldest layer in a geologic cross section?

Back

The oldest layer is typically found at the bottom of the cross section, according to the principle of superposition.

Front

How can fossils be used in relative dating?

Back

Fossils can be used to correlate the ages of rock layers; similar fossils found in different locations suggest that the layers were formed during the same time period.