Rocks and Rocks and The Rock CycleThe Rock Cycle

• Rock is a solid material made up of one or more minerals or other substances, including the remains of once-living things.

Types of RocksTypes of RocksTypes of RocksTypes of Rocks1)1) Igneous RockIgneous Rock

2)2) Sedimentary RockSedimentary Rock

3)3) Metamorphic RockMetamorphic Rock

Igneous Rock

Igneous rock forms when magma or lava cools and hardens.

Igneous Intrusive Rocks are formed from magma beneath the surface.

gabbo

granite

pegmatite

diorite

Igneous Extrusive Rocks are formed from lava on the surface

andesite

pumice

scoria

obsidian

Sedimentary RockSedimentary rock forms when particles of rock and

other materials are pressed and stuck together Erosion moves sediment from place to place on

Earth’s surface. Sediment is laid down in a process called

deposition. Slowly thick layers of sediment build up and the

weight of the layers above presses down on the layers below. The process is call compaction, squeezes the layers of sediment together.

Another process, called cementation, glues the sediment together.

Three major types of sedimentary rocks

1. Clastic rocks are pieces of rocks that have been pressed and stuck together.

siltstone

conglomerate

2. Organic rock are formed from the remains of plants and animals.

limestone

coal

3. Chemical Rock areformed when dissolved minerals come out of solutions and form crystals.

iron ore

rock salt

Metamorphic Rock

Heat and great pressure deep beneath Earth’s surface can change rock to metamorphic rock

Sometimes heat from a volcano causes nearby rock to become metamorphic rock

Metamorphic Rocks

granite becomes gneiss

sandstone becomes quartzite

The Rock CycleThe Rock Cycle Forces inside Earth and the surface Forces inside Earth and the surface

produce a rock cycle that builds, produce a rock cycle that builds, destroys, and changes the rocks in destroys, and changes the rocks in the crust.the crust.

The The rock cyclerock cycle is a series of processes is a series of processes on and beneath Earth’s surface that on and beneath Earth’s surface that slowly change rocks from one kind to slowly change rocks from one kind to another.another.

Igneous, sedimentary, and metamorphic rocks change

continuously through the rock cycle