Geologic Principles Flashcards

Front

Soil profile

Back

Cross section of soil layers and bedrock in a particular region

Front

Horizon

Back

A layer in a soil profile

Front

Geologic column

Back

The order of rock layers

Front

Law of superposition

Back

The assumption that layers found lower in rock formations are older than layers found closer to the top of the formation

Front

Fault

Back

Fracture in the earth’s crust along which rocks move

Front

Intrusion

Back

Occurs when a large mass of igneous rock is forced between or through layers of existing rock

Front

Inclusions

Back

As rocks are eroded, small parts of the rock break away and become ingrained in a separate, nearby layer of rock

Front

Unconformity

Back

Where layers of rock are missing because they have been eroded away, leaving a gap of missing information in the geologic record

Front

Fossil

Back

“Dug up”; preserved remains or impression of an organism that lived in the past

Front

Index fossils

Back

Fossils that are easy to recognize, plentiful, found throughout the world, and believed to have existed for only a relatively short period of geologic time