Geologic Time Review

Front

What is the shortest geologic time span group of organisms?

Back

Humans

Front

What is the term for the time it takes for half of a radioactive element's atoms to decay?

Back

Half-life

Front

What is the name for all time before the Cambrian explosion of life?

Back

Pre Cambrian Time

Front

What was the Paleozoic era known as?

Back

The age of fish

Front

What was the Mesozoic era known as?

Back

The age of reptiles

Front

What was the Cenozoic era known as?

Back

The age of humans

Front

If a fault cuts through two lower layers of rock, how does its age compare to the layers?

Back

Younger

Front

What is the significance of the Cambrian explosion?

Back

It marks a major increase in the diversity of life forms on Earth.

Front

What is radioactive dating?

Back

A method used to determine the age of materials by measuring the decay of radioactive isotopes.

Front

Define unconformity in geology.

Back

A surface of contact between two groups of unconformable strata.