Unit 3 Lesson 8 - Reconstructing Earth's History Test

How old is the Earth?

• hundreds of years

• thousands of years

• millions of years

• billions of years

When fossils appear in one rock layer but not in the next, what likely happened?

• mass extinction

• the organisms moved

• the organisms evolved very quickly

• the environment was no longer prone to creating fossils

Mass extinctions mark the end of one __________ and the beginning of another.

• cycle

• day

• geologic time span

• decade

Which is the shortest unit of time?

• eon

• era

• period

• epoch

What era do we live in?

• Cenozoic

• Mesozoic

• Paleozoic

• Precambrian time

Why is there so much information about the Phanerozoic eon, which is only 10% of Earth's history?

• Weathering was much worse before this eon.

• There aren’t many rocks left from previous eons.

• The Earth didn’t have a crust before the Phanerozoic.

• Most of the Earth’s crust was formed during this epoch.

The solar system formed according to the _________.

• big bang theory

• nebular hypothesis

• planetary formation model

• stellar evolution theory

Meteorites are good evidence for determining Earth's age because they formed __________.

• after Earth

• before Earth

• at the same time as Earth

• very recently

During Earth's formation, _________ elements like iron moved to the core, and ___________ elements rose to the surface.

• light; heavy

• heavy; light

• radioactive; stable

• stable; radioactive

What is the Iron Catastrophe?

• iron shortage in the 1940s

• formation of Earth’s iron core

• disruption of rock strata by iron ore

• impact of the Canyon Diablo meteorite