Geologic time and Relative age dating rock

The principle of _________ states that an intrusion or fault is younger than the rocks it cuts across.

• uniformitarianism

• cross-cutting relationships

• original horizontality

• superposition

If a horizontal Devonian shale directly overlies a horizontal Ordovician limestone, what is the surface between the strata called?

• an erosional surface

• a disconformity

• a nonconformity

• an angular unconformity

The __________ states that the processes that have been occurring today have been occurring since Earth formed.

• principle of superposition

• principle of uniformitarianism

• principle of original horizontality

• principle of cross-cutting relationships

What geologic principle states that in an undisturbed rock sequence, the oldest rocks are on the bottom and the youngest are on the top?

• uniformitarianism

• cross-cutting relationships

• original horizontality

• superposition

What is an erosional contact between sedimentary and nonsedimentary rocks called?

• a fault

• a disconformity

• a lava flow

• a nonconformity

What principle of geology states that sedimentary rocks are deposited horizontally or nearly horizontally?

• cross-cutting relationships

• original horizontality

• uniformitarianism

• superposition

What is the current era?

• Archean

• Cenozoic

• Paleozoic

• Mesozoic

What marks the end of the Proterozoic Eon?

• free oxygen

• mammals

• oxygen breathing organisms

• the first appearance of organisms with hard parts

What is the longest division of time in the geologic time scale?

• an era

• an epoch

• a period

• an eon

What is the shortest division of time in the geologic time scale?

• an epoch

• a period

• an era

• an eon