Geologic Time and Dating Methods Flashcard

Front

What is the Principle of Superposition?

Back

In an undisturbed sequence of sedimentary strata, the layers on the bottom are the oldest.

Front

What type of unconformity occurs when sedimentary rock is deposited on top of igneous and metamorphic rocks?

Back

Nonconformity.

Front

What does the principle of lateral continuity state?

Back

Layers of sediment extend outward in all directions until they thin out or encounter a barrier.

Front

Who is known as 'the Father of English Geology'?

Back

William Smith.

Front

What is the largest division of time in the geologic time scale?

Back

Eon.

Front

What is an Angular Unconformity?

Back

An unconformity where younger sedimentary layers are deposited on top of older, tilted or folded layers.

Front

Define Disconformity.

Back

A type of unconformity where layers of sedimentary rock are parallel but there is a gap in the geological record.

Front

What is the significance of the Principle of Original Horizontality?

Back

It states that layers of sediment are originally deposited horizontally under the action of gravity.

Front

Explain the Principle of Cross-Cutting Relationships.

Back

If a geological feature cuts through another, the feature that has been cut is older.

Front

What is a Fossil?

Back

The preserved remains or traces of ancient organisms, often found in sedimentary rock.