General Science-Types of Rocks

Question 1

The earth’s rocks fall into how many categories?

Answer 1

3

Question 2

This rock formed from the hardening of molten rock or magma.

Answer 2

Igneous

Question 3

Examples of Igneous are what?

Answer 3

Granite
Pumice
Basalt
Obsidian

Question 4

This rock is formed by the sedimentation, or gradual depositing, of small bits of rock, clay, and other materials. Over time this deposited material becomes cemented together. Most fossils are found in these rocks.

Answer 4

Sedimentary

Question 5

Examples of Sedimentary are what?

Answer 5

Shale
Sandstone
Gypsum
Dolomite
Coal

Question 6

This rock is formed when existing rock material is altered through temperature, pressure, or chemical processes.

Answer 6

Metamorphic

Question 7

Examples of Metamorphic are what?

Answer 7

Marble
Slate
Gneiss
Quartzite

Question 8

What are the 3 rocky categories?

Answer 8

Igneous
Sedimentary
Metamorphic

Question 9

The history of our planet often has been learned by studying what?

Answer 9

Fossils found in sedimentary rock.

Question 10

How do we know the earth’s age?

Answer 10

By studying rocks

Question 11

How old is the earth?

Answer 11

Approximately 4.6 billion years old

Question 12

The Precambrian Eon are how many years ago?

Answer 12

Between 4.6 billion and 570 million years ago.

Question 13

According to the few fossil records we have, when is it estimated that life began on earth?

Answer 13

3.5 billion years ago