Geology EXAM 2
Solifluction
Slow, downslope flow of water-saturated materials common to permafrost areas
waste disposal (radioactive decay), biological impact, mining locations, production of earthquakes/tsunamis
what are some concerns associated with the production of nuclear energy?
displacement, landslides, sediment liquefaction, tsunamis
what are some damages caused by earthquakes?
metamorphic grade
a measure of the intensity of temperature and pressure conditions that lead to alteration
moment magnitude
a more precise measure of earthquake magnitude than the Richter scale, which measures the amplitudes of several different seismic waves and determines the dimensions of the slipped area and estimate displacement
evaporites
a natural salt or mineral deposit left after the evaporation of a body of water; type of chemical sedimentary rock
superposition
a principle that states that originally younger rocks lie above older rocks if the layers have not been disturbed
hydrofracturing
a process that cracks subsurface rock using high-pressure water with additives and sand; used more today to stimulate wells because many are not permeable
sandstone
a sedimentary rock that is composed of different mineral compositions of sand-sized grains, and can be classified based on proportion of quartz, feldspar, and lithic and found in nearly every depositional environment
absolute dating
a technique used to date events using geologic 'clocks' and, depending on the dating method, have errors of years to millions of years; finds numerical ages; uncertainty scales with magnitude
glacial unconformity
a type of disconformity in which a glacier has come in--> eroded a lot of material and deposited new sediments on top
residual heat from planet formation and heat from radioactive decay in the crust and mantle
what are the 2 sources of geothermal energy?
l waves and r waves
what are the 2 type of surface waves?
shortening, stretching, shearing
what are the 3 S's that cause deformations?
liquid water load, surface slope, gravity
what are the 3 factors of hydraulic potential gradients dictating the flow of rivers?
biochemical, organic, chemical
what are the 3 types of non-clastic sedimentary rocks?
dissolved, suspended, and bed
what are the 3 types of sediment transport?
slope instability, planes of weakness, undercutting
what are the 3 ways to initiate mass movement?
Hadean, Archean, Proterozoic, Phanerozoic
what are the 4 eons from oldest to most recent?
mining and milling, conversion, enrichment, and fuel fabrication (can take place in different places)
what are the 4 major processing steps for nuclear fuel?
p waves
what are the first type of seismic waves to arrive at a station?
surface waves
what are the last type of seismic waves to arrive at a station?
wind, water, ice, and gravity
what are the modes of sediment transport?
s waves
what are the second type of seismic waves to arrive at a station?
compression (shortening of space)
what causes anticlines and synclines to form?
indonesia
what country has the largest capacity for geothermal expansion?
china
what country has the most coal?
Kazakhstan, canada, australia
what country is leading in mining production and reserves of uranium? what are the countries following it?
france
what country is the leader of providing the most energy in the nuclear energy of their total electricity generation?
united states
what country is the top leader of nuclear electricity generation capacity?
russia
what country produces the most nuclear fuel during enrichment?
atmospheric patterns, ocean circulation, animal migration/isolation, and continentality
what did the break-up of supercontinents influence?
vertical displacement pushes water up--> gravity pulls the bulge down--> up-down motion begins
what generates tsunamis?
sand grains and smaller
what grain size can wind transport move?
continental rifting
what is a result of stretching?
moment magnitude
what is now the most widely used form of magnitude?
uranium ore
what is the choice material for nuclear fuel?
marine environments
what is the depositional environment of most source rocks for oil and gas?
between 70-80 and 81-98 mW/m^2
what is the global average of heat flux at the surface?
area/wetted perimeter
what is the hydraulic radius equal to?
Paleozoic, Mesozoic, Cenozoic
what is the order of eras of the Phanerozoic Eon (oldest to most recent)?
wind, sand
what kind of sediment transport can move sediments across continents? what size sediments can it move?
population density, distance from epicenter, nature, types of buildings, after effects, sediment type
what other factors influence earthquake damages?
wastewater disposal
what part of hydrofracturing really causes earthquakes to occur?
fine grains
what size grains are typical carried in a suspended load?
large rainfall events
what speeds up the process of slumping?
250-850 degrees celsius
what temperatures does metamorphism occur between?
strike-slip fault
what type of boundary does shear stresses occur at?
peat
what type of coal has the least amount of carbon and the greatest amount of volatile compounds?
anoxic environments
what type of environment is critical to forming oil and gas?
convergent
what type of plate boundary does compressive stresses occur at?
divergent
what type of plate boundary does tensional stresses occur at?
clastic
what type of sedimentary rock makes up 3/4 of all sedimentary rocks?
pull/extensional
what type of stress produces normal faults?
push/compressive
what type of stress produces reverse faults?
push/compressive
what type of stress produces thrust faults?
shear
what type of stress produces transform faults?
l waves
what type of surface waves are the most damaging?
convergent
what type of tectonic boundaries do accretionary prisms form at?
geometry of channel itself
when calculating a river's discharge, the area reflects the _____
2.3 billion years ago
when does the atmosphere become oxygen-rich?
4.5 billion years ago
when was the formation of earth?
all major continents
where are Proterozoic shields commonly found globally?
rivers
where are conglomerates likely to be found?
water source
where are nuclear power plants always located near?
low elevations
where are river channels likely to be found?
low elevations by ridges of mountains
where are river channels likely to be found?
East Antarctic and African
where are the 2 largest Proterozoic shields located?
North America
where are the most Archean cratons found?
middle east
where are the most oil reservoirs located?
swamp and marshes
where does coal form?
inside a nuclear power plant
where does fission take place?
Gulf of Mexico
where does most of the rivers in the US drain into?
landslides
where is breccia likely to be found?
glacial environments
where is diamictite likely to be found?
sedimentary rocks
where is the largest pool (reservoir) of carbon on earth?
west
where is the most coal located in the US?
fault line/trace
where you can see the fault on the surface
deeper, narrower
will a shallow, wide channel or a deeper, narrower channel be more efficient at draining water?
strike-slip fault
a type of fault where rocks on either side move past each other sideways with little up or down motion; occurs at transform boundaries; due to shear stress
fission
currently used to yield tremendous quantities of energy used to run nuclear power plants
increase, decrease
higher coal grade--> ___ in carbon content and a ____ in volatile compounds
greater
higher grade coal such as bituminous and anthracite form at ______ temperatures and pressures
strict rules, lots of data, and debates
how are time scales determined?
99
how many nuclear reactors are there in the US?
20%
how much of the US's total electricity generation is nuclear?
angularity
how round/angular grain edges are
earthquakes
hydrofracturing can cause ____
angular
if edges of sediment are ___ --> indicates shorter distances traveled and less time
cross-cutting relations
if one geologic feature cuts across another, the feature that has been cut is older
greater
if there is an increase in friction--> there is ____ resistance of downslope movement
decrease
increase in vegetation--> ___ in erosion
angular edges
indicate that the sedimentary rock has not moved far from its depositional source
rounded edges
indicate that the sedimentary rock has travelled longer distances and for a longer amount of time bumping into things along the way--> has been transported a farther distance away from its depositional source
grain composition
indicates resistiveness, mixing processes, and sorting processes
point bar
inside ends of the bends of a river; where sediment builds up; slower velocity
decreases
intensity ____ from the epicenter of an earthquake
paleocurrents
it is important to measure ____ in the sediments in addition to measuring the strike and dip
surface waves
l and r waves arrive at any particular point on the surface substantially after the arrival of body waves
focus
location where seismic waves are first generated
burial metamorphism
low-grade metamorphism that is caused by the deep burial in a basin
natural gas and coal
make up 30% of world energy use
dissolved load
material that is chemically carried in the water
pressure solution
metamorphic process in which mineral grains partially dissolve where their surfaces press together--> dissolved ions migrate in a thin water film and reprecipitate in areas where pressure is low
deformation
metamorphic process in which mineral grains soften and deform when rock is squeezed or sheared at elevated temperature and pressure--> minerals change shape without breaking, behaving like a plastic
recrystallization
metamorphic process in which minerals change size and shape through dissolution and growth of crystals; the composition of the minerals does not change
phase change
metamorphic process that is a change from one mineral to another mineral of the same composition, but different crystalline structure (atoms rearrange)
neocrystallization
metamorphic process that is the formation of new metamorphic minerals from old minerals, as they become unstable and undergo chemical reactions that recycle elements to form a new mineral assemblage
tree rings
method of absolute dating based on correlation of ring patterns--> high accuracy, but limited range method of dating
rhythmic dating
method of absolute dating which uses seasonal or annual layers of sediment, ice, and tree rings (ages since inception of record)
sediment transport by water
method of transport of sediments in which MORE energy is required to entrain (lift) grains from the bed than to keep them in motion
radiometric dating
method that uses naturally decaying isotopes to determine ages; type of absolute dating
maturity
mineralogical, sorting, angularity and is influenced by time
sediment transport by wind
mode of transport of sediments in which low density, low viscosity "fluid" and the principles of entrainment, transport, and deposition, are similar to those for water
leave a small footprint, emit no greenhouse gases, and require less water
modern closed-loop geothermal power plants are considered 'clean' because they ____.
clastic sedimentary rocks
most common sedimentary rocks; made up of mostly silicate sediments bound together; important source of earth's resources
source, reservoir, trap
need a ___ of fossil fuels, a ____ to store it and a ___ so you are able to exploit it
non-clastic sedimentary rocks
not composed of pre-existing rocks; usually formed from a chemical reaction
intermediate-focused earthquakes
occur between 60-300 km of the earth
deep-focus earthquakes
occur down to a depth of 660 km (limit-- cannot occur any deeper than this)
shallow-focus earthquakes
occur within 60 km of the Earth (most within 5-20 km)
metamorphism
occurs due to pressure, temperature, stress, and chemically active fluids causing mineral and textural changes in rocks while rock is still in solid phase
creep
occurs when sediments slowly shift their positions downhill; process happens slowly over time as it adjusts to the bed changing below
economic stability
oil reservoirs are important for estimating ____
Diamictite
sedimentary rock composed of large clasts (gravel and larger) of varying degrees of angularity/roundness with an abundant fine-grained matrix and is poorly-sorted
conglomerate
sedimentary rock composed of rounded gravel, pebbles, cobbles, or boulders along with smaller sediments; travel longer distances (rounded edges)
bed load
sediments transported along the bed by sliding, rolling, or hopping
l waves (love waves)
seismic surface waves that are shear waves that cause the ground to shimmy back and forth and are the most damaging
r waves (Rayleigh waves)
seismic surface waves that are shear waves that cause the ground to undulate up and down
S wave patterns
seismic wave patterns that travel from the epicenter out around the core only staying within the mantle--> travel out to the sides
p wave patterns
seismic wave patterns that travel out from the epicenter in all directions and pass through the core and mantle; are refracted when they pass through the core
crust
seismic waves are felt when they reach the _____
surface waves
seismic waves that travel along the Earth's surface; slowest waves
body waves
seismic waves that travel through the interior of Earth
source
shale and limestone are ___ of carbon
s waves
shear body waves and travel at about 60% of the speed of the other type of body waves; only pass through the mantle (solid)--> cannot travel through liquid core
dynamic metamorphism
shearing in a fault zone
aftershock
shock that occurs after the main shock and is usually 10x smaller than the main shock
compressional
shortening =
sorting
similarity of grain size/shape
little organisms (diatoms, microorganisms, etc)
what are responsible for creating carbon and trapping it in the ocean?
waste disposal, biological impact, mining locations, production of earthquakes/tsunamis
what are some concerns associated with nuclear
thermal metamorphism
heating by a plutonic intrusion
subduction metamorphism
high pressure and low temperature alteration
solifluction and creep
2 examples of slow processes that can occur on steep slopes that are prone to failure?
footwall and hanging wall
2 walls associated with faulting
strike-slip behavior originating from pre-existing faults or energy released from previously intact rock
2 ways earthquakes can be generated
crude oil, natural gas, coal
3 types of fossil fuels
push, pull, shear
3 types of stress at a fault
oil
33% of world energy use was ____
magma intrusion beneath a volcano, landslides, meteor impacts, fracking
4 reasons why an earthquake may occur?
biochemical sedimentary rocks
A sedimentary rock that forms from the chemical activities of organisms; ex: chalk, micrite, chert
syncline
A downward fold in rock formed by compression (shortening of space); bowl shaped feature
fossil succession
A relative dating principle (w/ mix of absolute dating) stating that fossil organisms succeed one another in a definite, irreversible, determinable order; the age succession of fossils in the outcrop are used to date rocks
normal fault
A type of fault where the hanging wall slides downward and the footwall slides upward; caused by tension (pull) in the crust; footwall block on the left and hanging wall block on the right; occurs at divergent boundaries
foliation
Caused by differential stress--> extensive high-T shearing; banded appearance; develops perpendicular to compression, minerals flatten, recrystallize, and rotate; inequant grains align by rotation and new growth
Archean Eon
Eon extending from the time that life originated, 3.8 billion years ago, to 2.5 billion years ago
epicenter
Point on Earth's surface directly above an earthquake's focus
lateral continuity
Principle that states that layers continue laterally until they thin out to nothing (pinch out) and then later can be cut by erosional processes
slumping
Rapid mass movement which involves a whole segment of the cliff moving down-slope along a saturated shear-plane or line of weakness; material moves downslope rapidly
liquids
S waves cannot travel through while p waves can
footwall
The block of rock that forms the lower half of a fault-- below the fault; rock mass below the fault plane
hanging wall
The block of rock that forms the upper half of a fault-- above the fault; rock mass above the sloping fault
accretionary prism
The build up of sediments along the subduction plate margin; squeezed and uplifted--> with the highest and deepest part closest to the subduction zone-- root is under the highest part of the mountain
Holocene Epoch
The current interglaciation period, extending from 10,000 years ago to the present on the geologic time scale.
Hadean Eon
The earliest period in Earth's history-- 4.5 to 4.0 billion years ago
Phanerozoic Eon
The most recent eon, an interval of time from 542 Ma to the present.
stratigraphic correlation
The process of matching up strata from several sites through the analysis of chemical, physical, and other properties; powerful tool for understanding subsurface and exploiting the subsurface (for fossil fuels)
p waves and s waves
What are the 2 types of body waves?
planes of weakness
Zones of weakness caused by expansion due to batholiths
round
___ edges indicates farther distances traveled and for more time
faulting
___ is a result of brittle failure
earthquakes, tsunamis
____ --> landslides --> ____
time-travel curves
____ indicate the time delay between p waves and s waves
velocity
____ of water affects how much energy is required to lift grains from the bed and to keep them in motion
smaller, larger
____ rivers join with ____ ones-->____ in stream order as larger rivers are formed
local measurements
_____ are taken of heat flux at the surface and then interpolated to create a map of the global heat flux at the surface
greater
a ___ hydraulic radius will be more efficient--> less in contact with the bed--> less friction
shorter, longer
a bed load will move ___ distances and a suspended load can move ____ distances
fault scarp
a cliff created by movement along a fault--> it represents the exposed surface of the fault prior to modification by weathering and erosion
hydraulic radius
a measure of how much of the flow is in contact with the bed
reverse fault
a type of fault where the hanging wall slides upward and the footwall slides downward; caused by compression (push) in the crust; hanging wall on the left and footwall on the right; 60 degree angle; occurs at convergent boundaries
quantitative
absolute dating provides ____ data
hydrothermal metamorphism
alteration by hot water leaching
stick-slip behavior
alternation between stress buildup and earthquake generating slip events on a fault
anticline
an upward fold in rock formed by compression (shortening of space); like a hill
angular unconformity
angle/orientation of rock above and below a boundary do not align or match up
pairs
anticlines and synclines often occur in ____
pre-existing fault earthquakes
as stress builds across a frictionally locked fault, rocks adjacent to the fault bend elastically--> when friction becomes great enough that the anchor like bumps break or scratch a furrow in the opposite wall, the fault slips again
folds
bends that form by shearing and/or by slow plastic flow
disconformity
boundaries defined by an erosional surface representing a hiatus in time between underlying and overlying deposits
nonconformity
boundaries marked by sediments/sedimentary rock on bed rock/basement rocks (from in subsurface and are exposed at surface)-- sedimentary rocks on top of igneous or metamorphic rocks
crystallization; biochemical
calcite forms through ___ of shells from oysters, clams, etc. and is an example of a _____ sedimentary rock
strain
change in shape via deformation--> creates geological structures
shearing
changing orientation
sheetwash, gravity
channel initiation begins when ____ starts flowing downslope due to ____
travertine
chemical sedimentary rock composed of calcium carbonate and precipitated from ground water; found in caves and hot or cold water springs
dolostone
chemical sedimentary rock formed by a reaction between solid calcite and magnesium bearing groundwater
chemically precipitated chert
chemical sedimentary rock formed when other material is replaced by microcrystalline quartz; ex: quartz replaces calcite in limestone
grain size
classifications based on size ranges
larger, extreme
climate gradients on supercontinents were ___ and more ____
relative dating
comparative method of dating the older of two or more fossils/sites, rather than providing a specific date; puts geological events in chronological order without requiring a specific numerical age be assigned to each event
shortening
compression of space, material is being squeezed into a small space, forming mountains
p waves
compressional body waves that travel the fastest and increase with pressure and temperature; can travel through solids and liquids
organic sedimentary rocks
consists primarily of carbon-rich relicts of plants or other organisms; formed through burial and lithification; ex: oil shale, and coal
protolith
controls the initial mineral composition of a metamorphic rock
watersheds
define where water (or drainage basins) ultimately drain
distortion and displacement
deformation results in ____
denudation
destruction of mountains by erosion
velocity x area
discharge equals:
Richter scale
earthquake magnitude is measured on the logarithmic ____
elastic strain energy
energy that is released when the rock straightens out and generates earthquake vibrations
pressure
equal magnitude in all directions
East African Rift
example of a continental rift where tensional stresses stretch and pull rocks apart producing a normal fault
San Andreas Fault
example of a strike-slip fault
slumping, lahars, mudflows, debris flows, rockfalls, and landslides
examples of fast processes that can occur on steep slopes that are prone to failure?
vegetation accumulates in oxygen poor water, peat accumulation, buried and heated, chemical reactions drive off hydrogen, nitrogen and sulfur as gases and leave remaining residue coal made of about 70% carbon
explain the process of coal formation
shock metamorphism
extreme high pressure from an impact
fault displacement
fault slips tells us about the direction of _____
active or inactive
faults can be ___ or ____
hydraulic potential gradients
flow of rivers is driven by ____
chemical sedimentary rocks
formed primarily by minerals precipitated directly from water solutions
joints
fractures that have no offset
heat flux is high
geothermal expansion is tied to where ____ at the surface
high grade
grade of metamorphism that occurs at high temperature and pressure
low grade
grade of metamorphism that occurs at low pressure and low temperature
earthquake
ground shaking due to a release of energy that propagates through the crust of the Earth
cut banks
outside of the bends of a river where sediment is being eroded; faster velocity
solids
p waves and S waves can both travel through ___
pressure and temperature
p waves increase with ___ and ____
Shield
part of a craton in which the usually Precambrian basement rocks crop out extensively at the surface, surrounded by sedimentary rocks and/or sediments--> Proterozoic
suspended load
particulate sediment that is carried in the body of the flow
faults
planar breaks in the crust marked by offset of the two walls; a fracture plane on which sliding takes place
regional metamorphism
pressure and temperature change due to orogenesis
original horizontality
principle stating that sediments are deposited originally horizontally and can become tilted over time--> caused by tectonics, earthquakes, degree of metamorphism; oldest=bottom and youngest=top
Uniformitarianism
principle stating that the processes observed today were the same in the past; including tectonics, earthquakes, river processes, beach deposition, marine organisms collecting on seafloor; present is the key to the past and the past is the key to the future
fission
process involving certain radioactive atoms that can be fragmented to produce a great amount of nuclear energy
orogenesis
process of mountain building
late Anthropocene start
proposal that human impacts on the environment surged in the mid-twentieth century, a trend visible in many records and that radioactive fallout from nuclear blasts peaked in the mid-twentieth centering, leaving a signal visible in sediments
early Anthropocene start
proposal that humans began transforming the land surface thousands of years ago, through agriculture and other activities; one potential stratigraphic marker is a rise in the atmospheric concentration of methane millennia ago which is recorded in glacial ice--> could reflect increases in farming and animal herding
earthquake intensity
refers to the degree of ground shaking at a particular locality
qualitative
relative dating provides ____ data
primary productivity
river sediment delivery to ocean feeds _____
permanent rivers
rivers in which water is flowing all year and are common where there is abundant rainfall, groundwater discharge and low rates of evaporation
ephemeral rivers
rivers that do not flow all year and are common in places with low annual rainfall, a low water table, and high rates of evaporation
continental shelves
sediment deposition from rivers builds up on _____
breccia
sedimentary rock composed of gravel, pebbles, cobbles, or boulders; have a sharper, angular shape; deposited very near the source area
cyanobacteria
simple, single-celled organisms that came to life ~3.5 Ga (blue-green algae) and is thought to be one of the earliest forms of life on Earth and added more oxygen to the atmosphere through photosynthesis; form bacterial mats called stromatolites
foreshocks
smaller shocks preceding the major earthquake
stretching
solid earth behaves in different manners--> evidence of brittle failure of the crust; forms ridges and basins as landscapes are being pulled apart
craton
stable part of continental crust that has survived the merging and splitting of continents and supercontinents for at least 500 million years--> Archean
more
steeper slope--> ___ unstable
shear stress
stress parallel to plane
normal stress
stress perpendicular to plane
differential stress
stress that is greater in one direction
extensional
stretching =
perpendicular
strike and dip are always ____ to each other
seismology
study of earthquakes and the waves that propagate from them
tsunamis
submarine landslides could generate ____
downslope
surface water moves ____
slowest
surface waves are the _____
high, low
the United States has ___ current capacity for geothermal production and ___ additional capacity under development
displacement
the amount of movement across a fault
dip
the angle that a rock surface makes with a horizontal plane (cross-section orientation); angle!!
Modified Mercalli intensity scale
the damage of the earthquake and people's perception of the shaking
seismogram
the data record from a seismograph depicting the earthquake wave behavior, particularly the arrival times of the different waves, which are used to determine the distance to the epicenter
tectonic activity
the depth to the temperature variation in which metamorphism takes place varies with _____
strike
the direction of the line formed by the intersection of a rock surface with a horizontal plane (map direction); compass direction
earthquake magnitude
the energy released from the seismic source as recorded by the amplitude of ground shaking
deep time
the immense, almost unimaginable, span of geologic time
4x, 20x
the life cycle of GHG emissions from geothermal plants are ___ less than solar and up to ___ lower than natural gas
local magnitude
the logarithmic Richter scale measures _____
non-foliation
the metamorphic rock texture in which mineral grains are not arranged in planes or bands; no planar fabric because they lack inequant minerals and/or they recrystallized without differential stress, and they typically lack original textures and fossils in the limestone or dolostone protolith
4.8
the oldest tree is ____ thousand years old
Precambrian
the time span ranging from the formation of Earth 4.56 billion years ago to about 542 million years ago
elastic rebound theory
theory that rocks that are strained past a certain point will fracture and spring back to their original shape; the fundamental theory behind earthquakes forming from previously intact rock or pre-existing faults
Proterozoic Eon
time period ranging from 2,500 and 542 million years ago--> free oxygen, multi-cellular organisms.
anthracite
type of coal containing the most carbon; takes the longest time to form; loses volatile compounds through burial and lithification
thrust fault
type of reverse fault in which the fault plane is nearly horizontal rather than vertical; 30 degree angle instead of 60 degree
ocean
ultimate place rivers want to drain into is ___
settling velocity
velocity at which grains can resettle back to the bed
eroded, deposited
velocity variations in rivers are important for where sediment is ___ and ____
high, low, least
water flows from areas of ___ elevation to areas of ___ elevation along the path of ___ resistance
undercutting
wave erosion--> causes thinning at the bottom of a rock cliff--> causes it to become weak and fall
tsunamis
wave produced by displacement of the seafloor; can be produced by earthquakes
sediment liquefaction
wet sand grains settle together and the pressure in the water filling the space in pores between grains increases which leads to quicksand and quick clay--> slumping and settling
downslope forces (gravity) and resisting forces
what 2 forces initiate mass movement?
water flow velocity, bed resistance, and amount of vegetation
what 3 factors does erosion depend on?
topography, type of river bed, climate, vegetation
what 4 factors does the amount of transported material depend on?
increase in erosion or sediment transport with urbanization and agriculture, rapid changes in biosphere, abruptions in carbon, nitrogen, and phosphorous cycles
what are a few markers that could define the Anthropocene?
open pit mines
what are notorious polluters of water supply?
