Flashcards

Geoscience Exam 3

megan.feret Inglês 110 flashcards

Flashcards do conjunto (110)

1Mountains frequently occur in _____, _____ belts.Elongate, linear
2What is orogenesis?-the process in which mountains are constructed by tectonic plate interactions
3Young mountains are:-high
-steep
-growing upward
4Middle-aged mountains are:-dissected by erosion
5Old-aged mountains are:-deeply eroded
-often buried
6_____ strains creates geologic structures.-Deformation
7What are joints?-planar rock fractures that have no offset
8What are folds?-layers that are bent by slow plastic flow
9What are faults?-planar fractures that are offset by movement across the break
-abundant and occur at a variety of scales
-can be active or inactive
-sudden movements along faults=earthquakes
10What is a compression fault?
11What is a tension fault?
12What is a shear fault?
13What is a brittle (shallow) fault and a ductile (deep) fault?
14What is foilation?-planar metamorphic fabric
15Deformation results in one or all of the following:-translation
-rotation
-distortion
16What is translation?-change in location
17What is Rotation?-change in orientation
18What is Distortion?-change in shape
19What are two major deformation types?-brittle
-ductile
-depends on the temperature and pressure
-transition between the two occurs in the deeper crust
20What is Brittle Deformation?-rocks break by fracturing
-occurs in the shallow crust
21What is Ductile Deformation?-rocks deform by flow and folding
-occurs in the deeper crust
22What are the geometric features created by Deformation?-folds, faults, joints, etc.
-often preserve information about stress fields
233D structural orientation is described by ___ and ___.-strike and dip
24What is a Strike?-horizontal intersection with a titled surface
25What is a Dip?-angel of surface down from the horizontal
-always perpendicular to strike
-measured downslope
26Identify a strike and dip on a map
27What is a hanging wall block?-above the fault
28What is a footwall block?-below the fault
29What is the motion of a dip-slip?-block move parallel to fault plane dip
30What is the motion of a strike-slip?-blocks move parallel to fault-plane strike
31What is the motion of a oblique-slip?-a combo of a dip-slip and strike-slip
32What is a Reverse Fault?-hanging wall moves up
-thrust fault: special type of reverse fault where angle <30 degrees)
-accommodate crustal shortening (compression)
33What is a Normal Fault?-hanging wall moves down
-accommodate crustal extension (pulling apart)
34Describe the motion of a right lateral strike-slip fault.-opposite block moves to the observer's right
35Describe the motion of a left lateral strike-slip fault.-opposite black moves to the observer's left
36What does a fold look like?-layered rocks deformed into curves
-occurs in variety of shapes, sizes, and geometrics
37What is the hinge of a fold?-portion of maximum curvature on a fold
38What is the limb of a fold?-less curved "sides" of a fold
39What is the axial plane of a fold?-imaginary surface defined by connection hinges of successively nested folds
40What is an Anticline fold?-arch-like fold
-limbs dip away from the hinge
-
- -
- -
- -
41What is a Syncline fold?-trough-like fold
-limbs dip toward the hinge
- -
- -
- -
-
42Anticline and Synclines occur in ____.Series
43Folds are described by _____ _____.hinge geometry
44Plunging fold has:hinge that is tilted
45Describe the formation of an Anticline plunging fold"V" at the surface in the direction of the plunge ^
A
46Describe the formation of a Syncline plunging fold"V" at the surface going in the opposite direction of the plunge V
S
47Nonplunging fold has:horizontal hinge
48What is a dome?-an anticline in all directions
-fold with appearance of an overturned bowl
-erode to expose old rocks in center and older outside
49High mountains are supported by ____ ____.thickened lithosphere
50Thickening is caused by ___ ___.collisional orogenesis
51What is the average thickness of the continental crust?-35 to 40 km thick
52What is the average thickness beneath orogenic belts?50 to 70 km thick
53This thickened crust helps ___ the mountains ____.buoy; upward
54Mountain building is driven by ____ ___.plate tectonics
55What are convergent plate boundaries?-subduction related volcanic arcs grow on overriding plate
-accretionary prisms (off-scraped sediment) grow upward
-thrust faults stack up on the far side of the orogen
56What are continental collisions?-oceanic lithosphere can completely subduct
-this closes the preexisting ocean basin
-brings two blocks of continental crust together
-buoyant continental crust will not subduct
-instead, subduction is extinguished
57What is rifting?-continental crust is uplifted in rift settings
-thinned crust is less heavy; mantle response isostatically
-decompressional melting adds asthenospheric magma
-increased heat flow from magma expands and uplifts rocks
-rifting creates linear-fault block mountains and linear basins
58What are the 5 fundamental sources of energy?1. nuclear fusion in the Sun
2. the pull of gravity
3. nuclear fission reactions
4. energy in the interior of the Earth
5. Energy stored in chemical bonds
59__ and __ are hydrocarbons.oil and gas
-complex organic molecules
-made of hydrogen and carbon
-from once-living creatures
60Oil and gas form in specific ___ ____.T ranges
61What is the temperature of oil and gas?90-160 degrees celsius
62What is the temperature of gas only?160 to 250 degrees celsius
63What is the temperature of graphite?>250 degrees celsius
64A known supply of oil is call an:oil reserve
65Creation of an oil reserve is dependent on:-a source of rock
-a migration pathway
-a reservoir rock
-a trap
66What matters about the source rock for oil?-organic-rich black shale is the source of oil and gas
-organic mater is transformed within the oil window
-source rock does not store oil or gas
67What happens with the migration pathway for oil?-oil and gas migrate from source rock to reservoir rocks
-rock fractures and ground water facilitate migration
68What is the reservoir rock?-porous and permeable
-store hydrocarbons
-can leak to form an oil seep at the surface
69What is a trap?-a geological configuration that holds oil and gas
-trap geometry is often crucial for fluid collection
-exploited to recover hydrocarbons
70What is a seal?-a low-permeability rock layer above a reservoir
-exploited to recover hydrocarbons
71What is a salt-dome trap?-dominant offshore Gulf of Mexico oil/gas play structures
72When and where was the first the oil well drilled?-1859
-Titusville, PA
73What is natural gas?-alternative hydrocarbon
-volatile short-chain hydrocarbon
74What is tar sands?-alternative hydrocarbon
-deposits of residual petroleum in sand
75What is oil shale?-alternative hydrocarbon
-shale containing abundant kerogen
76What is shale gas?-alternative hydrocarbon
-shale rock containing abundant gas
-recent boom due to modern technology in hydraulic fracturing (fracking) under high pressure to create artificial fractures around well bores
77What is gas hydrate?-alternative hydrocarbon
-methane (CH4) in a cage of water ice
78What is coal?-black
-brittle
-carbonaceous
-sedimentary rock
79Coal is the remains of ___ matter from ____.-organic
-vegetation
80Coal is an important:-global energy source
-CO2 emitter
81Coal is only found in rocks younger than:420 Ma
82Coal formation requires ___ and ____.heat and pressure
83Coal compaction and decay turns plant debris into ____.-peat
-abt 50% carbon
-cut out of a wetland deposit
84Coal ___ ___ squeezes out water.burial compaction
85At depth, heat alters the plant material. __,__,and__ are expelled as gases. ___ content increases.H,N,and S
C
86At __ carbon, this solid plant material becomes coal.70%
87What is the carbon classification of peat?50% carbon
88What is the carbon classification of lignite?70% carbon
89What is the carbon classification of bituminous?85% carbon
90What is the carbon classification of anthracite?95% carbon
91What is nuclear power?-energy from breaking apart atomic nuclei
-neutrons strike the fuel and start fission
-fission splits a large nucleus into smaller fragments
92What are some of the cons of nuclear power?-expensive
-loss of reactor control may start core meltdown
-molten reactor materials could bore through containment
-steam explosion could then spread radioactivity
-plant safety
-extensive efforts applied to thwart terrorism
93When and where were there nuclear accidents?-1986; Chernobyl; spread radioactivity globally
-1979; three mile island (Penn,USA)
-2011; Fukushima (Japan)
94What kind of waste does nuclear power generate?-highly radioactive
-extremely toxic wastes are poisonous for 1000s of years
-high level waster storage is a major societal issue
-also generated by processing uranium ore
95What is geothermal energy?-energy from Earth's internal heat
96What is geothermal gradient?-Earth becomes hotter with depth
-vary 15 degrees celsius/km to 50 degrees celsius/km
-high geothermal gradients --hotter at shallower depths
97What two ways is geothermal energy utilized?-hot water is pumped and used to heat buildings
-steam is used to drive electric turbines
98What areas is geothermal energy dominant?-Iceland
-New Zealand
99What is hydroelectric power?-flowing water turns potential energy into kinetic energy
-works by eroding and moving sediment
-dams arrest the flow of water
-water is directed past turbines to create electricity
-some dams generate electricity via tidal flux
100What are the positive aspects of hydroelectric power?-reduces the rick of floods
-impounds water for drinking
-irrigation and recreation
-provides renewable energy w/o creating wastes
101What are the negative aspects of hydroelectric power?-dams destroy valued landscapes and alter ecosystems
-reservoirs accumulate the sediment load of the river
-sediments added to reservoirs require expensive dredging
-erosion is accelerated downstream of dams
102How is wind energy generated?-wind drives a large turbine to provide electricity
-wind derived electricity is renewable and carbon free
-wind farms sprouting worldwide
103What are the drawbacks of wind energy?-wind farms have negative aesthetic impacts
-turbine blades are noisy and kill birds
104___ ___ is the most abundant source of energy to the surface.solar energy
105Why is solar energy hard to utilize?-diffuse
-highly variable on a seasonal and daily basis
-difficult to convert into more usable forms of energy
106What is biomass?-energy from plant and animal matter
-early humans used biomass (wood, charcoal, dung)
-must be grown quickly
107A possible biomass we can use today:-ethanol: alcohol derived from corn
-burned as a motor fuel
-produced in large quantities
-unproven as gasoline replacement
108What are hydrogen fuel cells?-produce electricity via chemical reactions
-hydrogen reacts with oxygen in an electrolyte bath
-generates electricity, heat, and H2O
-reaction is environmentally benign
109Hydrogen Fuel Cells are useful as ___ for __ __.engines for motor vehicles
110What technology issues are associated with hydrogen fuel cells?-safely storing compressed hydrogen
-producing hydrogen efficiently
-distributing hydrogen