Geology Terms

Question 1

Sedimentary Rocks

Answer 1

Sedimentary rocks are usually grainy, and are sandy. They can be very crumbly and even broken into pieces. If you are able to use another rock to scratch off the grain it is most likely a sedimentary rock. Sedimentary rocks may contain fossils in them as shells when they were layering.

Question 2

Metamorphic

Answer 2

Metamorphic rocks are like sedimentary but harder, they usually have layers which are the rocks which have been compacted together. They are made intense heat and pressure, below the earth’s surface.

Question 3

Igneous

Answer 3

Igneous rocks are rocks which come from magma or lava, they are hard and also may be bubbly.

Question 4

Extrusive

Answer 4

Extrusive rocks are a type of igneous rock which are formed when lava is shot out of a volcano and it is cooled. Since these rocks are cooled quickly, they usually don’t have crystals, they are quite light weight and have small bubbles in them.

Question 5

Intrusive

Answer 5

Intrusive rocks are igneous rocks which have formed underneath the ground from magma. Since the magma is far away from the core of the earth the magma slowly cools down, this allows for the formation of crystals inside the rocks themselves

Question 6

Felsic Rocks

Answer 6

In a widely accepted silica-content classification scheme, rocks with more than 65 percent silica are called felsic. This leads them to have a lighter colour like white.

Question 7

Mafic Rocks

Answer 7

Rocks that have between 45-55 percent silica are considered Mafic rocks this leads to them having a darker colour.