ROCKSROCKS

Definition:Definition:

A rock is a mixture of minerals

Igneous RocksIgneous Rocks

Igneous rocks are formed as lava or magma cools.

a) Intrusivea) Intrusive If the magma cools

slowly beneath the surface, INTRUSIVE rocks result

INtrusive rocks form INside the Earth and have large crystals since there is time for them to form.

b) Extrusiveb) Extrusive If the lava cools

quickly on the surface EXTRUSIVE rocks result.

EXtrusive rocks have EXited the Earth and have small crystals since they formed so fast.

Other igneous rocks….

Sedimentary RockSedimentary Rock

Sedimentary Rock is made of sediment that has been compacted and/or cemented together.

Sedimentary Facts:75% of the Earth’s surface rock

is sedimentary.Sedimentary rocks store

ground water, oil, and coal.

Clastic Sedimentary rock is made of fragments of other rocks.

Organic sedimentary rock has traces of once living things in the rock.

Chemical sedimentary rocks are formed when minerals crystallize as a solution dissolves

Sedimentary rock is held together by COMPACTION and/or CEMENTATION:

During compaction, rocks are squeezed together because of a lot of pressure from above.

During cementation, rocks are held together by a mineral ‘glue’. Minerals fill in the spaces between the sediments and bind them together forming a solid rock.

Metamorphic RockMetamorphic Rock

Metamorphic rock is rock that has been changed due to heat and/or pressure.

Foliated metamorphic rock has bands of colors through it

Non-foliated metamorphic rock does not have bands of color.

Rock Cycle – Rock Cycle – any rock can become another rockany rock can become another rock