Download LET`S ROCK - Net Start Class

LET’S ROCK
The rock cycle shows the continuous changing of one rock type to another.
Rocks are a mixture of minerals, mineraloids, glass or organic matter.
Igneous rocks form from the cooling of magma or lava. They are the most
abundant type of rock.
 Basaltic igneous rock is from the cooling of lava. It has small crystals
due to rapid cooling at the earth’s surface. It makes up the oceanic
crust. It is dense, heavy, contains Fe and Mg, and is usually dark
colored.
 Granitic igneous rock is from the cooling of magma. It has larger
crystals due to the slower cooling deep within the earth. It makes up
the continental crust. It is light colored, low density, and contains Si
and O.
Metamorphic rocks are “changed rocks”. They are formed from heat and
pressure (enough to change the rock, but not enough to melt it!).
 Foliated metamorphic rocks have minerals in flat parallel bands, often
alternating light and dark minerals. The heat and pressure occurs in
one direction.
 Nonfoliated metamorphic rocks do not have bands. The heat and
pressure is in all directions.
Sedimentary rocks are formed from compaction and cementation of other
particles that have been eroded and deposited.
 Clastic sedimentary rocks are formed from other rock particles.
 Chemical sedimentary rocks are formed from dissolved minerals.
 Organic sedimentary rocks are formed from one living organisms.