Geology Final

Front 1

Nebular Hypothesis

Back 1

A-gravity pulled atoms together, forming a dense, hot core (100 yrs)
B-gas around core forms a flattened, rotating disk
C-6 bill yrs ago:corereached mill of degrees, becomes a protostar
D-fusion of H atoms began, forming heavier elements (takes 1 mill yrs)

Front 2

Planetary Accretion

Back 2

build-up of larger bodies via collisions of smaller particles

Front 3

Compositional Layers of the Earth

Back 3

1. Crust (light elements-Si, Al)
2. Mantle (Denser elements-Fe, Ni)
3. Outer Core (some O, S)
4. Inner Core (just Fe, Ni)
Crust:
-Continental Crust differs from oceanic crust

Front 4

Physical Layers of the Earth (5)

Back 4

1. Lithosphere (crust&upper mangle, strong/brittle)
2. Asthenosphere (ductile/plastic)
3. Mesosphere (lower mantle, rel. solid)
4. Outer Core (liquid)
5. Inner Core (solid)

Front 5

Alfred Wegener's "Continental Draft"

Back 5

Continental boundaries sort of fit together.
Mesosaurs (small aquatic reptile)-fossil found in S. Africa& in S. America.

Front 6

Plate Tectonics

Back 6

determine climate, flora&fauna, volcanoes, earthquakes, rock&mineral distribution, fossil fuel deposits, etc)

Front 7

Magnetic Anomalies

Back 7

found in seafloor rocks. age of ocean crust increased away from central rift (central spreading ridge)

Front 8

Age of Seafloor

Back 8

they also found age anomalies of seafloor rocks

Front 9

Convection

Back 9

plate movement-hot, low density material moves upward displacing cooler, higher density material

Front 10

Ridge Push Model

Back 10

buoyant material near mid-ocean ridge pushes plates apart and they slide downhill

Front 11

Slab Pull Model

Back 11

subducting plate pulls the rest of the plate down

Front 12

Slab Suction

Back 12

descending plates sucks down some adjacent material, causing circulation

Front 13

What happens at boundaries where 2 plates meet?

Back 13

1-pull away from each other
2. run into each other
3. slide past each other

Front 14

Mineral

Back 14

naturally occurring, inorganic, crystalline solid possessing a set chemical composition

Front 15

Rocks

Back 15

non-living substance compromised of 1+ minerals and possibly other minerals

Front 16

Rock Cycle

Back 16

-starts with Magma (liquid rock)
-magma freezes (when closer to surface) to form igneous rocks
-then surface processes act on rock (weathering, erosion, deposition, lithification)
-form sedimentary rocks (creates metamorphic rocks)

Front 17

Partial melting

Back 17

some parts of the rock (a mineral) can melt, but another (a different mineral) won't

Front 18

How to melt a rock

Back 18

1-increase temperature
2-add water (wet melting-adding water lowers the melting point of rocks&minerals)
3-lower pressure (decompression melting-removing pressure lowers the melting point of rocks&minerals)

Front 19

Partial freezing

Back 19

different minerals crystallize (aka freeze) at diff. temperatures

Front 20

Crystal Settling

Back 20

dense minerals sink, so they're not in contact with the magma

Front 21

Igneous Rocks

Back 21

1-plutonic (intrusive)
2. volcanic (extrusive)

Front 22

Crater (Volcano)

Back 22

smaller. vent for gases & other materials

Front 23

Caldera (Volcano)

Back 23

often several kilometers. form by collapse following eruption

Front 24

Shield Volcanoes

Back 24

low domes

Front 25

Tephra (Cinder) Cones

Back 25

lots of pyroclastic material

Front 26

Stratocones

Back 26

(aka-composite volcanoes, stratovolcatnoes) pyroclasts and lava

Front 27

Supervolcano

Back 27

eruptions large enough to affect global climate due to amount of material erupted

Front 28

Hot Spots

Back 28

As magma rises through the lithosphere, a volcano is formed above.
When lithosphere plate moves, the volcano is carried away and becomes dormant.
A new volcano forms over the hot spot.

Front 29

Parent Rock

Back 29

pre-existing rock

Front 30

Weathering

Back 30

breakdown of rock into sediment

Front 31

Physical

Back 31

1. Natural zones of weakness
2. Biological activity
3. Frost wedging
4. Exfoliation (isostatic rebound)

Front 32

Chemical

Back 32

1. Reacting with water: rain isn't pure water
2. Reacting with air: oxygen accepts electrons from other elements (oxidation)

Front 33

Controls on Weathering

Back 33

1. Speed
2. Parent Rock Type
3. Climate
4. Soil Presence/Absence
5. Length of Exposure (Rind-crust of rock)

Front 34

Erosion

Back 34

must move the sediment (water, wind, gravity, ice)

Front 35

Deposition

Back 35

as energy level drops, sediment can't be carried any further

Front 36

Basin

Back 36

any natural "crater"

Front 37

Subsidence

Back 37

(tectonics, weight) motion as surface shifts downward

Front 38

Accomodation Space

Back 38

Amount of space that sediment can fill in basins. Sediment is deposited in layers (strata, beds)

Front 39

Lithification

Back 39

process of becoming solid rock

Front 40

Compaction

Back 40

squeezes grains together-forms rocks

Front 41

Cementation

Back 41

Glues grains together. As water squeezes out, dissolved materials precipitate & "glue" sediment grains together.

Front 42

Clastic Sediments

Back 42

Produced by physical weathering. Classified by grain size.

Front 43

Chemical Sediments

Back 43

Produced by chemical reactions. Dissolution and re-precipitation. Saltwater evaporation (water evaps, salt stays in rocks)

Front 44

Biogenic Sediments

Back 44

Produced by animal and plants (Bio-life)

Front 45

Slope Stability Factors

Back 45

1. Consolidation-cohesive forces behind the material together. Becomes unstable if binding agents are removed (Clear cutting)
2. Slope Steepness-angle of repose (can vary a lot)
3. Moisture-can't have too little or too much
4. Vegetation- usually stabilizes but can destabilize. Roots.

Front 46

Creep

Back 46

slope slowly has mass wasting. Water every now and then moves down

Front 47

Solifluction

Back 47

slow like creep, but caused by repeated freeze/thaw action

Front 48

Causes of Mass Wasting

Back 48

1. Unstable slopes do NOT automatically have landslides
2. Possible triggers: earthquakes, oversaturation, grading slopes too steeply, removing vegetation cover

Front 49

Risk Assessment

Back 49

Can assess the risk along slopes, though factors may change over short timescale

Front 50

Prevention (to protect ourselves)

Back 50

Building Codes
Drainage Control
Decrease Slope Grades
Retaining Walls
Rock Bolts & other stabilizing devices

Front 51

Metamorphic Rocks

Back 51

Altering rocks via heat, pressure, or fluid interaction. Changes mineralogy and/or texture. Slow.

Front 52

Geothermal Gradient

Back 52

Temperature gradient within the Earth

Front 53

Confining Pressure

Back 53

pressure side to side is same as front to back and all directions (underwater pressure)

Front 54

Directed Pressure

Back 54

More pressure in one specific direction opposite of confining (aka-differential pressure)