Geologic time

Past environments can be determined using

• plate teconics

• fossils

• sea floor spreading

The Earth is estimated to be _____ years old

• 4.6 million

• 4.6 billion

• 46 million

• 46 billion

Which time period is the most recent?

• Mesozoic

• Cenozoic

• Paleozoic

One of three long units of geologic time between Precambrian and the present.

• evolution
• period
• geologic time scale
• era

Change over time for organisms.

• geologic time scale
• evolution
• era
• period

A record of the geologic events and life forms in Earth's history.

• index fossil
• half-life
• radioactive dating
• geologic time scale

In horizontal layers of sedimentary rock, each layer is older than the layer above it.

• mass extinct
• geologic time scale
• era
• law of superposition

One of the units of geologic time into which geologists divide eras.

• era
• geologic time scale
• period
• uncomformity

What Era are we currently in?

• Paleozoic

• Mesozoic

• Cenozoic

• Triassic

Which Era was dominated by dinosaurs?

• Paleozoic

• Mesozoic

• Cenozoic

• Cambrian