Chapters 5 and 6 Vocab

Front

Relative age

Back

The age of rocks and geologic features compared with other rocks and features nearby

Front

Superposition

Back

The principle that in undisturbed rock layers, the oldest rocks are on the bottom

Front

Unconformity

Back

A surface where rock has eroded away, producing a break, or gap in the rock record

Front

Index fossil

Back

A fossil representative of a species that existed on Earth for a short length of time, was abundant, and inhabited many locations

Front

Absolute age

Back

The numerical age, in years, of a rock or an object

Front

Eon

Back

The longest unit of geologic time

Front

Era

Back

A large division of geologic time, but smaller than an eon

Front

Paleozoic era

Back

The oldest era of the Phanerozoic eon

Front

Mesozoic era

Back

The middle era of the Phanerozoic eon

Front

Cenozoic era

Back

The youngest era of the Phanerozoic eon