Post on 03-Jan-2016
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.