What are Rocks?

Cornell Notes pg. 145

What is a Rock? • Naturally Occurring

• Solid

• Mixture of one or more minerals

• May contain organic matter

Discuss…

1. How are Rocks and Minerals similar?

2. How are they different?

Classifying Rocks

• Rocks are divided into three main categories based on how they were formed– Igneous– Sedimentary– Metamorphic

Classifying Rocks

• By composition- the minerals a rock contains.– Granite=

quartz + biotite + feldspar– Limestone= calcite + argonite

• By texture- the size, shape, and positions of the grains.

Think…

• Do rocks always stay the same?

How do rocks change?

• Weathering- rocks are broken down into smaller rocks and sand, (sediment)

• Erosion- sediment is removed from its source.

• Deposition- area where sediment comes to a rest.

• Heat and Pressure- can morph the rock or even cause the rock to melt and form magma.

What is the

Rock Cycle?

• Continual process by which new rock forms from old rock

• Rock may be changed from one type to another– Rock is Recycled!