Rocks and the Rock Cycle

Mr. Silva

Three Major Types of Rocks

• Igneous Rocks: “meaning from fire”

–Formed when magma cools and hardens.

– Magma is called lava when it reaches the earth’s surface.

Three Major Types of Rocks

• Sedimentary Rock:

–All types of rock, minerals, and organic matter that have been broken into fragments by forces.• Wind, water, ice

–Deposits harden after being compressed together.

Three Major Types of Rocks

• Metamorphic Rock: “changed form”

– When an existing rock undergoes extreme forces it changes form.

• Tremendous pressure• Extreme heat• Chemical processes

The Rock Cycle

• A cycle is a series of changes–Geological forces and processes cause rock to change from one type to another and back again.

–Rocks in the crust have passes through the cycle many times.

The Rock Cycle