Rock Layers and Fossils Flashcard

Front

What is the Law of Superposition?

Back

The principle that in undisturbed rock layers, the oldest rocks are at the bottom and the youngest rocks are at the top.

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What does absolute age mean?

Back

The actual age of a rock or fossil in years, determined through methods like radiometric dating.

Front

What is relative age?

Back

The age of a rock or fossil in comparison to other rocks or fossils, without determining the exact age.

Front

What is a fossil?

Back

Evidence that an organism once lived or existed, often preserved in rock.

Front

What is the significance of rock strata?

Back

Rock strata are layers of sedimentary rock that provide information about the Earth's history and the organisms that lived at different times.

Front

What is the difference between absolute dating and relative dating?

Back

Absolute dating provides a specific age in years, while relative dating places rocks and fossils in chronological order without exact dates.

Front

What is an unconformity in geology?

Back

A gap in the geological record that occurs when rock layers are eroded or when sediment is not deposited for a period of time.

Front

What does the Law of Cross-Cutting Relationships state?

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If a rock layer is cut by another feature (like a fault or intrusion), the feature that cuts through is younger than the layers it disrupts.

Front

What is a sedimentary rock?

Back

A type of rock formed by the accumulation and compaction of mineral and organic particles.

Front

How do fossils form?

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Fossils form when organisms are buried quickly by sediment, which protects them from decay and allows for mineralization.