The Rock Cycle

What’s Energy Got to Do With It?

But First!

Some background information…

What are Rocks?

Rocks are aggregates of 2 or more minerals.

Petrology is the study of rocks.

There are three classifications of rocks: igneous, sedimentary, and metamorphic.

Igneous Rocks

Granite is an igneous rock

• Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as coarse-grained, intrusive (plutonic) rocks or on the surface as fine- grained, extrusive (volcanic) rocks.

Sedimentary Rock

Sedimentary rock is formed in three main ways:

Limestone and shale are both types of sedimentary rock

1. by the deposition of the weathered remains of other rocks (known as clastic sedimentary rocks)

2. by the deposition of the results of biogenic activity (organic)

3. by precipitation from solution (evaporites)

Metamorphic Rock

Metamorphic rock is the result of the transformation of a pre-existing rock type.

The pre-existing rock type is called the protolith.

Pressure and heat physically and chemically change the protolith.

Metamorphic means "change in form“.

Slate is a type of metamorphic rock

Finally, The Rock Cycle!

• The Rock Cycle refers to the constant sequence of one type of rock turning into another.

Click Here for an Animation that Further Explains the Rock Cycle

Magma

Sediment

Sedimentary Igneous

Metamorphic

What Do You Think?

• Now that you have seen the animation, what do you think energy has to do with the progression of the Rock Cycle?

• What are the keys to the change in the rocks?

• Can rocks shortcut the cycle? Does igneous always have to form sediment or can it go straight back to being magma?