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.