Ch 12: Geologic Time Scale

Front

What are the shorter time divisions that periods are subdivided into?

Back

Epochs

Front

What major changes do scientists use to determine the beginning and end of geologic time units?

Back

Life forms

Tags

NGSS.MS-ESS1-4

NGSS.MS-LS4-1

Front

Which era includes the Triassic, Jurassic, and Cretaceous periods?

Back

Mesozoic Era

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NGSS.MS-ESS1-4

Front

Which geologic time division is the youngest?

Back

Cenozoic Era

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NGSS.MS-ESS1-4

Front

What is the oldest time division in the geologic time scale?

Back

Precambrian Time

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NGSS.MS-ESS1-4

Front

What is the longest division of geologic time?

Back

Eon

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NGSS.MS-ESS1-4

Front

What is the term for a major division of geological time that is made up of several periods?

Back

Era

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NGSS.MS-ESS1-4

Front

What type of fossil is typically found in older rock layers?

Back

Fossils of ancient life forms

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NGSS.MS-LS4-1

Front

What is the significance of the Cambrian Explosion in geologic time?

Back

It marks a rapid diversification of life forms.

Tags

NGSS.MS-LS4-1

Front

What does the term 'Paleozoic' refer to in the geologic time scale?

Back

An era that lasted from about 541 to 252 million years ago.

Tags

NGSS.MS-ESS1-4