There are 3 Major There are 3 Major (Geologic)(Geologic) Rock GroupsRock Groups

Not the Rolling Stones, Kiss, or Van HalenNot the Rolling Stones, Kiss, or Van Halen

1. Igneous Rock1. Igneous Rock

2. Sedimentary Rock2. Sedimentary Rock

3. Metamorphic Rock3. Metamorphic RockRocks are made of Rocks are made of mineralsminerals

and make up Earth’s solid crustand make up Earth’s solid crust

A. A. Igneous RockIgneous Rock--Forms when a hot, molten liquidForms when a hot, molten liquid, , below ground, calledbelow ground, called magmamagma,, crystallizes (cools and solidifies).crystallizes (cools and solidifies).

Magma forms 3 ways:Magma forms 3 ways:1.1. Rock is heatedRock is heated2.2. Pressure releasedPressure released3.3. Change compositionChange composition

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a.a. Intrusive Igneous RockIntrusive Igneous Rock-Forms or crystallizes inside -Forms or crystallizes inside

EarthEarth-slow cooling-slow cooling

b. b. Extrusive Igneous RockExtrusive Igneous Rock-Forms on surface (exterior) of -Forms on surface (exterior) of

EarthEarth-Fast cooling-Fast cooling

Fine-grained-made of interlocking crystals. Ex: basalt - the most common extrusive igneous rock

BASALT

More Igneous Rocks…

Course grained texture= Granite,

the most common intrusive.

Sedimentary RockSedimentary Rock*There are *There are 33 types of sedimentary rocks. types of sedimentary rocks.*Often times, sand, mud, pebbles, or shells *Often times, sand, mud, pebbles, or shells

settle out in wind and water, get settle out in wind and water, get compacted and/or cemented together, compacted and/or cemented together, and harden into rock.and harden into rock.

Here, rocks hardened in layers called strata from a process known as… stratification.

3 Types of Sedimentary 3 Types of Sedimentary RockRock

1. 1. ClasticClastic - -forms when rock or mineral forms when rock or mineral fragments are cemented together.fragments are cemented together.

2. 2. ChemicalChemical forms when minerals forms when minerals crystallize out of solution, such as sea crystallize out of solution, such as sea water, to become rock.water, to become rock.

3. 3. OrganicOrganic forms from the remains of once- forms from the remains of once-living plants and animals.living plants and animals.

Ex: LimestoneEx: Limestone CoalCoal

ChalkChalk

Metamorphic RockMetamorphic Rock-Rocks that have undergone a change in -Rocks that have undergone a change in

texture, structure, or composition.texture, structure, or composition.

-Changes in heat and pressure cause rocks -Changes in heat and pressure cause rocks to change from one form to another.to change from one form to another.

Rocks are made, Rocks are made, destroyed, and created destroyed, and created

again, in a process called again, in a process called the the Rock CycleRock Cycle