ROCKSROCKS

What is a rock?What is a rock?

► A mixture of A mixture of mineralsminerals

►OR organic OR organic materialmaterial

.

Minerals make up rocks.

Natural compounds and elements combine to form minerals.

Elements combine to form the natural compounds.

Rocks make up the Earth.

There is a hierarchy to the elements of Geology

Atoms make up elements.

IGNEOUS ROCKSIGNEOUS ROCKS

► Made from the cooling of molten rockMade from the cooling of molten rock► Tough rock!Tough rock!► Interlocking crystalsInterlocking crystals

► Intrusive- cool from magma (underground); Intrusive- cool from magma (underground); large crystalslarge crystals

► Extrusive- cool from lava (surface); small Extrusive- cool from lava (surface); small crystalscrystals

► HOW DOES COOLING RATE AFFECT crystal HOW DOES COOLING RATE AFFECT crystal SIZE?SIZE?

IGNEOUS ENVIRONMENTSIGNEOUS ENVIRONMENTS

IGNEOUS CLASSIFICATIONIGNEOUS CLASSIFICATION

►TEXTURESTEXTURES Coarse – big (can see with naked eye) Coarse – big (can see with naked eye)

crystalscrystals Fine – small crystalsFine – small crystals Vesicular- holesVesicular- holes glassyglassy

►COLOR- based on composition of COLOR- based on composition of magma/lavamagma/lava Mafic (basaltic)- dark- denseMafic (basaltic)- dark- dense Felsic (granitic)- light-high in silicia less denseFelsic (granitic)- light-high in silicia less dense

►OBSIDIAN IS AN EXCEPTION-OBSIDIAN IS AN EXCEPTION-►Dark color is from impuritiesDark color is from impurities►Felsic rock (99% quartz)Felsic rock (99% quartz)

Lava flows in Michigan!Lava flows in Michigan!

HawaiiHawaii

Igneous RocksIgneous Rocks

Rhyolite

Gabbro

Granite

Basalt

SEDIMENTARY ROCKSSEDIMENTARY ROCKS

►Made from sedimentsMade from sedimentsgrittygritty►Not tough (fragile)Not tough (fragile)►Forms from-Forms from-

Compaction- due to pressure (shale)Compaction- due to pressure (shale)Cementation- solution sticks grains togetherCementation- solution sticks grains together

Evaporation- water evaporates leaves rockEvaporation- water evaporates leaves rockPrecipitation- saturated solution (limestone)Precipitation- saturated solution (limestone)

CLASSIFICATION OF SEDSCLASSIFICATION OF SEDS

►TEXTURESTEXTURES Clastic (Detrial) - made of piecesClastic (Detrial) - made of pieces

►grittygritty

crystalline (Chemical)- from watercrystalline (Chemical)- from water►Smooth; may see crystalsSmooth; may see crystals

Bioclastic - evidence of lifeBioclastic - evidence of life

Grand CanyonGrand Canyon

conglomerateconglomerate

coquinacoquina

sandstonesandstone

limestonelimestone

coalcoal

METAMORPHIC ROCKSMETAMORPHIC ROCKS

► Igneous or sed. rock that has changedIgneous or sed. rock that has changed

►Forms from heat and/or pressureForms from heat and/or pressure

►Form deep underground near the Form deep underground near the mantle- BUT DO NOT MELT!mantle- BUT DO NOT MELT!

Types of metamorphismTypes of metamorphism

►Contact- existing rock comes in Contact- existing rock comes in contact with hot magmacontact with hot magma Small scaleSmall scale Change from heatChange from heat

►Regional- from tectonic plate collisionRegional- from tectonic plate collision Large scaleLarge scale Change from heat AND pressureChange from heat AND pressure

CLASSIFICATION OF MET. ROCKSCLASSIFICATION OF MET. ROCKS

► FoliatedFoliated Flattening of Flattening of

mineralsminerals

►NON- foliatedNON- foliated Not flattened, Not flattened,

crystals get biggercrystals get bigger

Evidence of pressureEvidence of pressurefoliationfoliation

slateslate

marblemarble

schistschist

gneissgneiss

Mrs. Bouda’s favorite Rock!Mrs. Bouda’s favorite Rock!

Generalized Bedrock Geology

of Michigan

Igneous and Metamorphic

rocks

Sedimentary rocks

In Michigan,sedimentary rocks make up the bedrock in the eastern northern, and southern peninsulas.