Unit 2 Vocab Flashcard

Front

What is the largest unit on the geologic time scale?

Back

Supereon

Front

Which division of Earth's history spans hundreds of millions to billions of years?

Back

Eon

Front

What is a major division of geologic time that is shorter than an eon but longer than a period?

Back

Era

Front

Which subdivision of a geologic era represents a span of tens to hundreds of millions of years?

Back

Period

Front

What is a subdivision of a geologic period, spanning millions of years?

Back

Epoch

Front

What theory explains the formation of the moon?

Back

Giant Impact Theory

Front

What term describes the event when many groups of organisms disappear from the rock record at about the same time?

Back

Mass Extinction

Front

What is the sudden appearance of a diverse collection of organisms in the Cambrian fossil record called?

Back

Cambrian Explosion

Front

Which dating method measures the decay of radioactive isotopes in rocks?

Back

Radiometric Dating

Front

Which dating method uses comparison to determine the order in which objects were formed?

Back

Relative Dating