Geology- Lecture 1
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- Characteristics of a mineral
- solid, natural, inorganic, ordered internal structure, specific chemical composition
- Define: Crystalline Rock
- several types of minerals, brightly colored (crystals 2-4in)
- Define: Clastic rocks
- several types of minerals, pebbles all gray
- Define: Mohs Hardness Scale
- relative hardness's of the minerals, NOT true comparison of actual harness
- Is gold a mineral?
- Yes
- Is coal a mineral?
- no, its organic
- Is glass a mineral?
- no it doesn't have an ordered internal structure
- Is ice a mineral?
- yes
- Is water a mineral
- No
- What are three common atomic shapes in Minerals?
- cubic Tetrahedron Octahedron
- What are 6 ways of cleavage?
- one direction two perpendicular directions two non perpendicular directions three perpendicular directions three non perpendicular directions four directions of cleavage
- how are minerals classified?
- by the most abundant minerals
- chemical formula for silica
- SiO4
- How can silica tetrahedral be arranged? (5) **
- Independent tetrahedra (0livine) Single Chains (Augite) Double chains (Hornblende) Sheets/Phyllosilicates (Muscoite) Framework (Feldspar, Quartz)
- what are some common silicate minerals?
- silicon Quartz Potassium feldspar plagioclase feldspar muscovite mafic minerals amphibole pyroxene Garnet olivine Biotite clay
- What are some common nonsilicate minerals?
- carbonates (calcite, dolomite) evaportates (halite, gypsum) Oxides (Magnetite, hematite, goethite) sulfides (pyrite, galna) Native elements (dimond, gold)
- What is the chemical formula for calcite.
- CaCo3
- What is the chemical formula for dolomite
- CaMg( CO3)2
- What is the chemical formula for Halite
- NaCl
- What is Halite used for?
- table salt
- What is Gypsum used for?
- Dry wall
- Why is Hematite special?
- found on mars, and we know it forms under water
- What is the composition in the earths crust**
- 46% Oxygen 28% Silicon 8% aluminum
- Most abundant mineral in the universe?
- H
- Most abundant minerla for the entire earth
- Fe, O, Si, Mg
- Most abundant mineral for the crust
- O,Si,Al,Fe
- What is a rock?
- solid, naturally occurring, cohesive
- Is gypsum a rock?**
- yes and a pure mineral
- Is coal a rock?**
- yes
- Is beach sand a rock?
- No, not cohesive
- Define: Pegmatite and where is it formed?
- rocks with large cyrstals. formed in deep depths
- define medium grained crystals?
- crystals you can see with your eye
- define Phorphyritic
- large crystals in a fine grained matrix
- Define: Vesicles where are they formed?
- volcanic rocks that has small holes. formed under low pressure (the surface)
- What are igneous rocks made out of/
- the cooling of magma
- What is Porphyritic texture?
- a mixture of large and very small crystals
- What are phenocrysts?
- large crystals
- What is groundmass
- very small crystals
- Define: Phaneritic**
- visible crystals
- Define: Aphanitic**
- very small crystals
- What causes melting?
- a change in pressure a change in composition a change in water content heat generation
- what is magma called that cools beneath the surface
- intrusive igneou rocks or plutonic rocks
- what are some examples of intrusive igneous bodeis
- Stone Mountain, GA Yosemite National Park, Ca
- Bowen's Reaction
- highest temp forms first crystals olivine--> Prodene --> Amphibole-->potassum Feldspar--> Quartz
- Define: Mafic minerals
- lower Si content (the sugar in cookies) Higher melting points darker colored and denser form first
- Define Felsic Minerals
- higher Si content (the chocolate chips) lower melting temps lighter colored and less dense
- Felsic Intermediate Mafic Ultramafic Intrusive Extrusive
- Granite Diorite Gabbro Peridotite Rhyolite Andesite Basalt Komatiite
- Which forms first: Ultramafic, mafic or Felsic
- Ultramafic (olivine)
- What is the diff between rhyolite and basalt lava
- rhyolite lava is explosive basalt lava is slow moving
- What class is socria and pumice under
- socia=mafic pumice= felsic
- Define Porphyritic
- large plus small crystals
- Define: Phenocrysts
- large crystals
- Which mineral group reacts with HCl
- charbinate group
- Define: Geology
- the study of earth
- Define: Petrology
- study of rocks
- Define: Seismology
- study of earthquakes
- Where are Iron mines and why are they there?
- Up north around the great lakes. WHy? Most of NA didn't exist
- Where are copper mines and why?
- West Why? rockies blocked it from going father east
- which national park is a volcano
- Yellowstone national park
- Define: Glacial potholes
- formed when glacial melted away, water got caught in dents in the ground rock. A hard rock got caught in the dents. The water would swirl the rocks around and the hole would get deeper and the rock rounder
- Define: Lehar
- mud plus lava
- Steps in scientific method
- Observation Questions about observation hypothesis perdiction test prediction conclusion
- Define: method of multiple working hypothesis
- the process of proposing and testing multiple, hypotheses. Much harder
- How do most sediments form?
- weathering
- What are the four different types of physical weathering?
- near-surface fracturing Frost and mineral wedging thermal expansion biological activity
- Define:Near surface fracturing
- many processes on or near the surface break rocks into smaller pieces
- Define:Frost and mineral wedging
- rocks can be pried apart as water freezes and expands in fractures
- Define:thermal expansion
- sun heat or wildfires
- Define: Biological Activity
- roots grow downward into fractures and pry rocks apart
- What are the four different types of Chemical weathering?
- Dissolution Oxidation Hydrolysis Biological reaction
- Define: dissolution
- some minerals are soluble in water
- Define: oxidation
- unstable when exposed to oxygen in the earths atmosphere
- Define:Hydrolysis
- converts original materials to clay minerals
- Define:Biological reaction
- decaying plants produce acid which breaks the minerals in rocks
- What are the clast sizes?
- Breccia Conglomerate Sandstone Siltsone Mudstone Shale
- How big is:Sandstone
- visible to the eye
- How big is: Siltsone
- can't see with your eye, griddy to taste
- Define: Shale
- can't see with your eyes
- Chemical formula for: Limestone
- CaCO3
- Chemical formula for: Hailite
- NaCl
- Chemical formula for: Gypsum
- CaSO4
- Chemical formula for: Japer/Flint/Chert
- SiO2
- Define: Bioclastic sedimentary rocks:
- rocks containing abundant fossils or organic matter
- what are some examples of bioclastic rocks?
- coquina (mostly shell) fossiliferous limestone (farther along than coquina) Peat Coal
- What are three types of cement that creates sedimentary rocks?
- Calcite, Silica, iron oxide
- when do nonclastic rocks form?
- WHEN water evaporates
- when do biochemical rocks form
- when nonclastic rocks are extracted directly from the water by coral/ organisms
- Some examples of nonclastic sedimentary rocks
- Rock salt Gypsum limestone chalk dolostone chert iron formation peat coal
- Where does rock salt form?
- as lakes and seas evaporate
- where does gypsum form
- forms as seawater evaporates in tidal flat areas
- when does limestone form
- debris of sea animals
- how does Dolostone form
- if groundwater with magnesium encounters limestone
- How does Chert form
- layers of plankton shells that fall to the bottom of the ocean
- Define: Formation example
- a rock unit that is distant and laterally traceable example: Round Rock, Arizona
- Define:Bedding example:
- layers example: green river, Utah
- Define:Discrete events
- some individual layers may mark things like flodds
- why do sedimentary rocks have layers?
- discrete events, change in current, sea level change, climate change
- In sedimentary rocks what does color mean?
- red= terrestrial black= formed underground
- What does Symmetrical ripple marks tell you about a rock?
- a ocean or oscillating water was once there
- what does asymmetrical ripple marks tell you about a rock?
- water in a river or wind
- Define:strata
- layers of rocks
- Define:Stratigraphy
- the study of strata
- Define: transgression
- a rise in sea level limestone over mudstone over sandstone
- Define: Regression
- a drop in sea level sandstone over mudstone over linestone
- where is limestone formed?
- underwater
- what causes rocks to metamorphoses?
- pressure and heate and chemically active fluids
- Define regional metamorphism**
- plates bashing together (mountains). large scale
- Define: Contact metamorphism**
- At the edge of the magma chamger
- High amounts of stress applied to a rock can lead to: (3)
- Displacement Rotation Strain (changing size or shape)
- Define: Low grade
- if temp and pressure on the rock are low
- Define:High grade
- if temp and pressure on the rock are high
- What happens to shale when you add pressure and temp
- shale -> Slate (harder) -> Phyllite --> Schist-> Gneiss-> melts
- what happens to sandstone if you add pressure and heat?
- Sandstone-> Quart
- What happens to limestone if you add pressure and heat?
- Limestone->marble
- What happens to basalt/andesite if you add Pressure and heat?
- Basalt/Andesite -> greenstone -> greenschist -> gneiss
- What are 4 causes of metamorphism?
- increase in pressure increase of temp tectonic stress fluids
- Define: deformed objects
- flatten grains into a pancake like shape
- Define: rotation
- minerals rotate until they become parallel to each other
- Define: shearing
- align or stretching out of crystals
- Define: small scale folding
- folds happen with increasing amounts of deformation
- What are (3) chemcial process that occur during metamorphism?
- Pressure solution recrystallization remobilization
- What are (5) physical process that occur during metamorphism?
- deformed objects rotation shearing small scale folding fracturing
- Define: pressure solution
- materials dissove from the edges of grians and precipitate else where on the rock
- Define: remoblization
- diffuse dissolve or partially melt in one place and form somewhere else
- Define:Metamorphism without deformation
- burial pressure, new crystals form
- Define: Flattening one direction
- pancake shaped, rocks have foliation but not lineation
- Define: Flattening and stretching
- long thing, rocks have foliation and a lineation
- What are (9) rocks processes that cause metamorphic conditions?
- Sedimentary/volcanic burial tectonic burial subduction heating of magma crustal heating holt fluids changein stress Shearing shock metamorphism