Geologic Time , Earth Layers, Drifting of Supercontinents

In which PERIOD do we currently live?

• Cretaceous

• Holocene

• Quaternary

• Pleistocene

What epoch are we currently in?

• Precambrian

• Jurassic

• Mesozoic

• Holocene

The longest division of geologic time is an

• Age

• Period

• Epoch

• Eon

• Era

Answer explanation

the shortest is an Age

What collective name for several eons spans about 90% of earth time?

• Jurassic

• Ordovician

• Devonian

• Precambrian

Which era is known as the "age of dinosaurs"?

• Phanerozoic

• Proterozoic

• Hadean

• Mesozoic

Which era is known as the "age of Mammals"?

• Archean

• Hadean

• Phanerozoic

• Cenozoic

Earth is ________________ years old!

• 13.8 billion

• 4.28 billion

• 4.6 billion

• 10,000

Answer explanation

the oldest rocks are 4.28 billion from the Hadean

Gravitation Contraction helped heat up early earth because

• everything was blowing outward from a supernova explosion

• the spinning of the planet pulled heavier elements inward and friction between those minerals rubbing together created heat

• the revolution of the earth around the sun meant that our surface remained molten

• it pulled hot asteroids into the Earth's surface, adding new hot rock periodically.

One of earth's first minerals kept it very warm in the Precambrian age because it is radioactive and as it decayed it released heat, this mineral was

• Silica

• Uranium

• Iron

• Sulfur

Earth's differentiated structural layers are because some minerals are more dense than others; which mineral is most often found in our center most core because of how heavy and dense it is?

• silica

• iron

• oxygen

• carbon