Earth's History

Front

relative dating

Back

determining whether an object or event is older or younger than other objects or events

Front

unconformity

Back

a place where an old, eroded rock surface is in contact with a newer rock layer- shows a gap in the rock record

Front

uniformitarianism

Back

theory that states that the geologic processes that shape Earth are uniform through time

Front

superposition

Back

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

Front

original horizontality

Back

Principle stating that sedimentary rocks are deposited in horizontal or nearly horizontal layers.

Front

cross cutting relationships

Back

Principle stating that a fault or intrusion is younger than the rock it cuts across.

Front

contact metamorphisim

Back

change in the structure and mineral composition of rock surrounding an igneous intrusion

Front

subsidence

Back

a geological phenomenon in which the ground in an area sinks

Front

uplift

Back

lift up; elevate; raise

Front

weathering

Back

Break down of rock pieces