History of Earth vocab quizz

Front

Age of a rock compared to others.

Back

Relative Age

Front

Age of rock in years since formation.

Back

Absolute Age

Front

Geologic principle stating that in horizontal layers of sedimentary rock, each layer is older than the one above and younger than the one below.

Back

Law of Superposition

Front

Gap in geologic record where rock layers are lost due to erosion.

Back

Unconformity

Front

Process where radioactive nuclei break down, releasing particles and energy.

Back

Radioactive Decay

Front

Determining the age of an object using the half-life of radioactive isotopes.

Back

Radioactive Dating

Front

Record of Earth's geologic events and life forms.

Back

Geological Time Scale

Front

One of the three long units of geologic time between the Precambrian and now.

Back

Era

Front

Unit of geologic time dividing eras.

Back

Period

Front

An animal without a backbone.

Back

Invertebrate