Term
| 6 classifications of igneous rock |
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Definition
Felsic Intermediate Mafic
Intrusive Granite Diorite Gabbro
Extrusive Rhyolite Andesite Basalt |
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Term
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Definition
1. boulders
2. cobbles
3. pebbles
4. sand
5. silt
6. mud |
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Term
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Definition
-like a sill, but magma under it
-looks like a hill (swollen) |
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Term
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Definition
-basaltic magmas denser
-more viscosity=less density |
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Term
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Definition
-molten LIQUID w/ atoms and elements floating around (Si, O, Fe, etc.)
-700C-1300C |
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Term
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Definition
-viscous magma moves slowly
-silica-rich magmas are more viscous
-basaltic magmas not so viscous
-viscous magmas not as hot (silica-rich magmas not so hot) |
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Term
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Definition
-exposed bedrock
-still connected to continental crust |
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Term
| agate, chert, flint, chalcedony, jasper |
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Definition
| -cryptocrystalline quartz formed by fluid replacement |
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Term
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Definition
1. 2 or more minerals
2. naturally occurring
3. solid
4. minerals coherent; stuck together |
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Term
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Definition
-thick slurry formed when volcanic ash/debris mix w/ water
-water from rivers, rain, melting snow/ice |
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Term
| formation of joints in rock |
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Definition
-pressurized rocks rise
-as they rise, they expand
-as the expand they break along joint surfaces |
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Term
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Definition
-large wave along sea surface
-triggered by quake or submarine slump from volcano |
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Term
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Definition
| -shows sequence in which certain minerals crystallize |
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Term
| process from shale to schist |
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Definition
-shale to slate to phyllite to schist
-more heat/pressure causes realignment of mineral grains causes metamorphic reactions |
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Term
| types of sedimentary rock |
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Definition
1. clastic - formed by particles getting pressed together (sandstone)
2. chemical - evaporation of water (rock salt)
3. biochemical - formed at bottom of water due to deposit of biologic material, like shells (chalk)
4. organic - dead organic material (coal) |
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Term
| role of fluids in metamorphism |
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Definition
1. create veins in outcrops
2. hydrothermal fluids exchange ions quicker
3. fluids can percolate into rock and bring new ions (ION EXCHANGE)
4. fluids can react with minerals in rock |
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Term
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Definition
-textural term for igneous rock
-larger crystals in fine-grained matrix
-2 stages of formation (different crystals form at different heats) |
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Term
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Definition
-broad, gentle dome
-formation:
1. low-viscosity basaltic lava
2. large pyroclastic sheets |
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Term
| physical properties used to tell crystals apart |
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Definition
-color, pattern
-shape, facets, growth pattern
-taste (salt)
-density
-hardness
-translucency
-luster
-cleavage/fracture
-streak color |
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Term
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Definition
1. depth (it is cooler higher)
2. size of intrusion (surface area:volume)
3. ground water - holds heat, cools pluton faster |
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Term
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Definition
| shows which polymorph will form at which pressure and temperature |
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Term
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Definition
| -formed as surface of lava tube cools and magma flows down slop through crystallized tube |
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Term
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Definition
| 2 minerals with same chemical composition but different crystal lattice structure |
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Term
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Definition
-stick out of rocks
-formed by fluids
-silica-rich fluids flow through limestone, replace limestone with chert |
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Term
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Definition
1.heat
2.pressure
3.differential stress
4.fluids |
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Term
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Definition
-vesicular
-dark colored
-slightly more dense than pumice |
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Term
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Definition
-effect of metamorphism (little crystals fuse together and form bigger and more interconnected ones)
-increase in grain size
-crystals grow together |
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Term
| fractional crystallization |
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Definition
| process by which compositions of magma changes as certain minerals begin to form |
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Term
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Definition
-biochemical sedimentary rock
-composed of invisible silica
-cryptocrystalline quartz |
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Term
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Definition
-calcite that precipitates out of water
-deposited by hydrothermal fluids |
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Term
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Definition
-effect of metamorphism
-heat/pressure cause atomic bonds to break and minerals recombine
-rearrangement of atoms in solid rock creates new crystals/minerals |
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Term
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Definition
-formed from parts of dead organisms
-shells contain calcite |
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Term
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Definition
| fine particles that erupt from volcano |
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Term
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Definition
-effect of metamorphism
-rocks deform like playdoh because they're so hot
-crystal structure is squished, but doesn't break |
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Term
| 3 main factors that control minerals in a metamorphic rock |
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Definition
1. initial composition
2. heat
3. pressure |
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Term
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Definition
| about plum-sized particles from volcano |
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Term
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Definition
| thin vertical body of rock |
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Term
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Definition
| thin horizontal body of rock |
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Term
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Definition
-big hole left in center of volcano when al material flows out
-quite large
-explosions still possible |
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Term
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Definition
1.water squeezed out of pile of clasts as more sediments (1-2 km) piled on top
2.ions in moving groundwater form cement to hold rocks together |
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Term
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Definition
| ash that falls out a volcano cloud |
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Term
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Definition
-large volcanic particle
-liquid when it goes up, solid when it comes down |
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Term
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Definition
-happen quickly
-ground made unstable by thawing of frozen ground
-all in one piece |
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Term
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Definition
-vesicular
-light-colored
-less dense than scoria |
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Term
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Definition
-round body of igneous rock
-looks like a balloon
-rises |
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Term
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Definition
-melting in rock of minerals with low melting temperatures
-other minerals remains solid
-silica melts early, olivine late |
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Term
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Definition
-effect of metamorphism
-rocks under pressure from fluid on either side
-fluid dissolves rock where there is pressure from fluid
-redeposition of dissolved particles changes shape of rock |
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Term
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Definition
-similar to limestone
-formed from limestone deposit that's had fluids flowing through it |
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Term
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Definition
-banded metamorphic rock
-shear stress causes mafic and felsic layers to flatten and then fold over eachother |
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Term
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Definition
-discreet horizontal layers of sediment
-can see boundaries above and below
-different layers because depositional environment has changed (change in water) |
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Term
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Definition
-big volcanic deposit
-solid when it goes up and when it comes down |
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Term
| 3 main ways in which crystals grow |
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Definition
1. cooling from magma
2. out of solution - precipitation
3. solid state diffusion |
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Term
| igneous vs. metamorphic identification |
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Definition
-metamorphism: minerals grow in layers, foliated, stripes
-both have interlocking crystal structure |
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Term
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Definition
-caused by gravity
-huge chunk moving down hill, slowly or quickly |
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Term
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Definition
-made of several plutons
-HUGE |
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Term
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Definition
| solid in which atoms are not arranged in an orderly pattern |
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Term
| composition and subclassification in sedimentary rocks |
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Definition
-particle size matters in classification
-composition classifies too
- sand size particles made of quartz = quartz sandstone
- quartz and feldspar and sand-size particles is arkose |
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Term
| 2 types of differential stress |
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Definition
-normal:straight up and down
-shear:push along top or bottom
-foliation forms perpendicular to stress |
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Term
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Definition
| pressure in one direction |
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Term
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Definition
| coarse-grained igneous rock w/ crystals of up to 10 cm across and ocurring in dike-shaped intrusions |
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Term
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Definition
-rubble, sharp, angular
-formed when lava tumbles off side of cliff |
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Term
| types of chemical weathering |
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Definition
dissolution - dissolving of rock (through water)
oxidation - oxygen will eventually weather rock
hydrolysis - feldspar converting into clay minerals with a combination of water. Rain with granite causes hydrolysis |
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Term
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Definition
-initial explosion of material
-becomes too heavy
-falls back to earth
-surge down side of mountain
-300-400 km/hr |
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Term
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Definition
tuff - rock made of pyroclastic material
tephra - pile of pyroclastic material |
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Term
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Definition
-pressure of rocks squeezes liquid up
-doesn't go down because there's higher pressure below |
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Term
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Definition
-process by which large chunk freezes and warms, moving down mountain
-SLOW |
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Term
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Definition
-water percolates into rock
-hollows it out
-perfect crystals form |
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Term
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Definition
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Term
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Definition
-looks like rope
-formed from slow lava flow |
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Term
| 2 major minerals found in evaporate deposits |
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Definition
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Term
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Definition
-any rocks that melts
-deep w/in earth |
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Term
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Definition
-everything comes down mountain
-not in 1 piece
-avalanche |
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Term
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Definition
-larger clasts
-conglomerate is rounded
-breccia is angular |
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Term
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Definition
-there was a lot of water where mud was deposited
-mud dried up |
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Term
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Definition
-basaltic lave erupting under sea water
-forms in near perfect spheres |
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Term
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Definition
-formed as lava cools
-hexagonal columns
-mostly found in basalt flows |
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Term
| 5 steps in formation of sedimentary rocks |
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Definition
1. weathering - rock broken down by chemical/physical means
2. erosion - pieces removed by water, wind, ice
3. transportation - piece moved by water, wind, ice
4. deposition - stuff deposited somewhere, usually a body of water
5. lithification - sediments turned into rock through pressure because clasts are buried |
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Term
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Definition
1. solid
2. natural occurring
3. inorganic
4. definable chemical composition
5. crystalline strucutre |
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Term
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Definition
Vibration on earth's surface that results from:
- a slip on a fault
- formation of new fault
- movement of magma in a volcano
- volcanic explosion
- giant landslide
- meteorite |
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Term
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Definition
| point on surface of earth directly above focus of an earthquake |
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Term
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Definition
| location where fault slips during earthquake |
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Term
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Definition
| seismic waves that pass through interior of earth |
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Term
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Definition
-seismic waves in which particles of material move back and forth perpendicular to diretion in which wave itself moves
- also called s-waves |
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Term
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Definition
- waves in which particles of material move back and forth parallel to direction in which wae itself moves
- also called p-waves |
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Term
| behavior of waves in different rock types |
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Definition
- quicker through denser rocks (more rigid)
- therefore, quicker at depth |
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Term
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Definition
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Term
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Definition
-discovered crust/mantle boundary
-some seismic waves go down, hit the mantle, and bend back up. others just go through crust
-w/ closer seismograph station, crust wave arrives first
-w/ further seismograph station, mantle waves arrive first
-due to great density of mantle, although mantle wave travels further, waves travel faster through greater density |
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Term
| oceanic crust vs. continental crust |
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Definition
- CC: 35-40 km thick, density = 2.7g/cm cubed
- OC: 7-10 km thick; denisty 3 gm/cm cubes
- CC thicker under mountains (maybe 70 km) |
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Term
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Definition
- mantle largest by volume, much thicker than crust
- mantle composed entirely of PERIDITITE, which is mostly olivine
- mantle deforms ductily
- crust deforms brittley |
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Term
| upper mantle vs. lower mantle |
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Definition
- waves move at diff speeds throughout earth
- waves speed up in lower mantle
- UM: 3.5 g/cm cube
- LM: 5.5 g/cm cube |
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Term
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Definition
- Discovered thus:
- seismograph stations all over earth
- waves bend differently through core b/c of huge jump in density
- waves that enter core are significantly deflected
- outer core: 10-12 g/cm cube
- inner core: 14 g/cm cube |
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Term
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Definition
- p-waves go through solid and liquid, s-waves go through only solid
- s-waves that went through core never made it to other side of earth
- outer core liquid, inner solid |
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Term
| circulation of outer core |
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Definition
| causes magnetic force around earth |
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Term
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Definition
crust: granite (felsic)
mantle: periditite (mafic)
core: iron, nickel |
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Term
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Definition
| flowability; deformability of rock |
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Term
| division of earth based on rheology |
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Definition
low temps deform brittley
high temps deform ductiley |
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Term
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Definition
- relatively rigid, non-flowable outer layer of earth
- constitutes crust and upper part of mantle
- oceanic lithosphere: 100 km thick
- continental lithosphere: 150 km thick |
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Term
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Definition
continental drift
1. continental fit: looks like they could fit together
2. locations of past glaciations: glaciers should be found in polar regions. but there's evidence of glaciers far from poles.
3. equatorial climatic belts: coal swamps at where equator would've been
4. fossil distribution: fossil remains span several continents. oceans couldn't've always been there
5. matching geologic units: coasts on matching shoreline have same rock units |
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Term
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Definition
| couldn't explain HOW or WHY continents would move! |
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Term
| 2 technologies from 50s to change view of earth |
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Definition
1. sonar - discovery of mid-ocean ridges
2. paleomagnetic evidence - could see magnetism on ocean floor, and where poles had moves (polar wandering paths) |
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Term
| theory of plate tectonics |
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Definition
| lithosphere divided into rigid plates which move relative to eachother and to asthenosphere |
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Term
| elecation of continental lithosphere vs. oceanic lithosphere |
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Definition
- CL higher than OL (so water fills in oceans and we live on land)
- due to buoyancy
- oceanic crust is denser, also thinner |
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Term
| active continental margin |
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Definition
| continental margin that coincides w/ plate boundary |
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Term
| passive continental margin |
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Definition
| is not a plate boundary (east n.a.) |
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Term
| 3 general types of plate boundaries |
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Definition
convergent o-c, o-o, c-c
divergent o-o, (c-c eventually becomes o-o)
transform o-o, o-c, c-c (less common) |
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Term
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Definition
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Term
| earthquakes and plate boundaries |
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Definition
| earthquakes happen anywhere there are brittle rocks that break, but they are more common at plate boundaries |
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Term
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Definition
| glass encrusted basalt blobs that form when magma extrudes on the sea floor and cools very quickly |
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Term
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Definition
- linear belt along which continental lithosphere stretches and pulls apart
- if rifting is successful, it separates a larger continent into 2 smaller continents separated by a divergent boundary |
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Term
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Definition
- down going slab sinks beneath over riding plate.
- deep earthquakes
- volatiles released (O2, CO2), which cased mantle to melt, which caused volcanoes |
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Term
| subduction and earthquakes |
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Definition
- deepest eqs 660 km below surface
- happen at down-going slab
- dg slab continues to behave brittley as it sinks; eqs happen w/in plate |
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Term
| why does amt. of crust remain constant? |
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Definition
| plate movements balance each other out |
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Term
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Definition
| a curving chain of active volcanoes formed adjacent to a convergent plate boundary |
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Term
| collision of continental crust |
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Definition
- no subduction
- oceanic crust breaks off, two CCs collide
- forms big mountains
- less volcanic activity because mantle doesn't melt |
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Term
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Definition
- marks a transform plate boundary
- along mid-ocean ridges, t.f's are actively slipping segment of a fracture zone between 2 ridge segments
- usually found at mid-ocean ridges, but not always (e.g. san andreas fault) |
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Term
| transform fault EQs vs. subduction zone EQs |
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Definition
| - transform fault quakes are not nearly as deep |
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Term
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Definition
| radioactive elements decaying in mantle |
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Term
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Definition
| kind of melting that occurs when hot mantle rock rises to shallower depths in the earth so that pressure decreases while temperature remains unchanged |
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Term
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Definition
| movement of plate relative to fixed point in mantle |
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Term
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Definition
| movement of one lithospheric plate relative to another |
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Term
| yellowstone vs. hawaiian hot spot |
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Definition
- continental vs. oceanic plates
- hawaiin makes islands, basaltic magma
- yellowstone makes violent eruptions, felsic magma |
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Term
| variation of lave composition in volcanoes |
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Definition
- always involves melting magma
- composition depends on crust through which magma rises
- crust partly melts w/ rising magma
- cont crust more felsic (silica rich)
- oceaninc crust more mafic |
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Term
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Definition
| areas w/ extremely large amounts of lave flows |
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Term
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Definition
- huge mantle plume
- buoyant, rising, semisphere of hot mantle rock
- decompression melting occurs as it rises |
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Term
| columbia river flood basalt |
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Definition
- 175,000 km cubed of basalt
- 16 Ma old
- formation
1. yellowstone hot spot magma deflected to central WA
2. crustal thinning due to rifting - asthenosphere rises to fill lithosphere spots that have thinned - decompression melting occurs
- location: northern WA, toward Western side (mostly not on coast). also a tiny bit in BC |
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Term
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Definition
| not yet fully formed plate |
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Term
| geologic structures that result from formation of mountains |
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Definition
- Faults
- Folds
- Foliation
- Joints |
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Term
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Definition
| a fracture on which one body of rock slides past another |
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Term
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Definition
- ductile feature in which there is a highly concentrated area of deformation
- happens low down in areas where rocks deform ductily |
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Term
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Definition
- sliding occurs up or down the slope (dip) of the fault
- normal fault, reverse fault, low-angle normal fault, thrust fault |
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Term
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Definition
| moving block moves right relative to other |
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Term
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Definition
- one block slides horizontally past other
- parallel to strike line
- no relative vertical motion
- left-lateral; right-lateral |
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Term
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Definition
| the rock or sediment below an inclined plain |
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Term
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Definition
- a steeply dipping fault on which hanging-wall block slides up relative to footwall
- result of compression |
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Term
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Definition
- hanging wall block moves down the slope of a fault
- result of extension |
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Term
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Definition
- gently dipping reverse fault
- hanging wall block moves up slope of fault
- compression |
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Term
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Definition
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Term
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Definition
| moving block moves left relative to other |
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Term
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Definition
| the rock or sediment above an inclined fault plane |
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Term
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Definition
- naturally formed cracks in rocks
- no slip
- formed by stress or decompression
- sometimes preferred to g-bong rips |
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Term
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Definition
- f=ma
- stress=force/area
- strain results from stress |
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Term
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Definition
| - change in shape of rock in response to deformation (e.g. as result of application of stress) |
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Term
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Definition
1. extensional (stretch)
2. compression (contraction)
3. shear |
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Term
| old vs. young mountain belts |
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Definition
| - when tectonic forces that create mountains subside, erosion occurs, making old mountains shorter and rounder |
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Term
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Definition
1. change in location
2. change in shape
3. change in orientation |
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Term
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Definition
1. extensional
2. compressional
3. shear
*pressure is a special condition where stress is exerted about equally from all directions |
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Term
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Definition
- layering formed as consequence of alignment of mineral grains, or of compositional banding in a metamorphic rock
- ALWAYS perpendicular to primary stress |
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Term
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Definition
- a band or wrinkle of rock layers
- forms as consequence of ductile deformation |
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Term
| explanation of brittle and ductile features in same rock |
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Definition
- ductile deformation occurred at depth
- rate of deformation changed as rock rose |
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Term
| location of brittle, ductile deformation |
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Definition
brittle: closer to surface
ductile: 10-15 km down
- also depends on speed of plate collision |
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Term
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Definition
- process in which mountains begin to collapse under their own weight and spread out laterally due to intense heat
- limits height of mountains
- magma can form in late stage mountain-building if there's enough weight |
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Term
| sedimentary process of mountain building |
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Definition
- EROSION: more happens at higher altitudes
- bangladesh eroded from himalayas |
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