200 likes | 346 Views
ROCKS. Definition:. A rock is a mixture of minerals. Igneous Rocks. Igneous rocks are formed as lava or magma cools. . a) Intrusive. If the magma cools slowly beneath the surface, INTRUSIVE rocks result
E N D
Definition: • A rock is a mixture of minerals
Igneous Rocks • Igneous rocks are formed as lava or magma cools.
a) 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) 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.
Sedimentary 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 Rock • Metamorphic rock is rock that has been changed due to heat and/or pressure.