Geologic Time Review

half-life

unconformity

radioactive dating

Carbon-14

Pre Adolescent Time

Pre Apocalyptic Time

Pre Historic Time

Pre Cambrian Time

reptiles, fish, humans

fish, retiles, humans

fish, humans, reptiles

Silurian

Carboniferous

Permian

Devonian

Earth's rotation

tectonic plate motion

volcanoes and earthquakes

rock layers and index fossils

J

Z

D

F

sedimentary rock

index fossils

layers

decay fossils

approximately half of Earth's history

about 1/3 of Earth's history

a very tiny fraction of Earth's history

a large amount of Earth's history

to organize and sequence events by eras and periods in the different divisions of time and to serve as a timeline

to show the evolution of life forms and to model how those life forms behaved and what they ate

to organize and sequence events in the history of Earth and to serve as a model for a vast amount of time covered

to determine the relative ages of rocks and when and how they formed to create a timeline of their development

older

younger

the same

harder