8.1The Rock

Cycle

7.4.a Students know Earth processes today are similar to those that occurred in the past and slow geologic processes have large cumulative effects over long periods of time.7.4.c Students know that the rock cycle includes the formation of new sediment and rocks and that rocks are often found in layers, with the oldest generally on the bottom.

Hutton’s Big Idea

• Geology- the study of the structure of planet Earth and the forces that make and shape Earth

• Erosion- happens when running water, ice, or wind break down rocks and carry the pieces away

• Hutton’s idea is called uniformitarianism• Key concept-The principal of uniformitarianism

states that the geologic processes that operate today also operated in the past.

• Most geologic processes happen very slowly

Types of Rocks• Key concept- Geologists classify rocks

into three main groups- igneous, sedimentary, and metamorphic.

• Igneous- forms when molten material from beneath Earth’s surface cools and hardens (it can form on or below the Earth’s surface)

• Sedimentary- made of sediments that have been deposited and then pressed together

• Metamorphic- forms when an existing rock is changed by heat, pressure, or chemical reactions (most form under pressure deep underground)

Igneous

Sedimentary

Metamorphic

The Rock Cycle• Key concept: Forces inside Earth and at the surface produce a

cycle that builds, changes, and destroys rocks.

• Rocks change continuously through the rock cycle.

Rock cycle- a series of processes on and beneath Earth’s surface that slowly changes rocks from one kind to another

The Rock Cycle• Deposition- material (like sediment) being added to a

landform

The Rock Cycle• Erosion- the wearing away of rocks and other deposits

by the action of water, ice, wind, etc.

The Rock Cycle• Melting- caused by intense heat and pressure

beneath the surface of the Earth

Rocks and the Rock Cycle• Magma- molten material beneath Earth’s surface• Lava- when magma flows on the surface

Rocks and the Rock Cycle• Rocks change continuously through the rock cycle.

Rocks and the Rock Cycle• Rocks change continuously through the rock

cycle.