Geology Exam 3

what covers about 75% of the world’s land area?

sedimentary rocks

what is gravel, sand, silt or clay?

loose sediment

what forms when loose sediment is compacted or cemented?

sedimentary rocks

what is the process of converting sediment to sedimentary rock?

lithification

what do sedimentary rocks contain?

fossil record

what do we take resources (oil, gas, water, coal, ore) from?

sediments and sedimentary rocks

what type of sedimentary rocks are transported as grains?

clastic

what type of sedimentary rocks are chemical, biochemical, or organic?

non clastic

how do clastic sedimentary rocks form?

weathering → transportation → deposition

in general, does it take higher or lower energy to transport larger grains?

higher

what texture indicates deposition in quiet water?

fine grained

what type of sedimentary rocks are classified by grain size?

clastic

what are the main types of clastic sedimentary rocks?

conglomerate, sandstone, shale

what are conglomerate rocks made of?

rounded gravel sized rock clasts

how to conglomerate clasts round?

flowing water

what is sandstone made of?

sand sized particles

where is sandstone most common?

beach and dune settings

what is the most common mineral in sandstones?

quartz

what is this?

loose sediment

what is this?

sedimentary rock

what is this?

yellow cliffs, zion national park, utah

what is this?

great sand dune national park, colorado

what kind of sedimentary rock is made of clay sized particles?

shale

what is the most abundant sedimentary rock?

shale

where is shale or mudstone most prevalent?

quiet water depositional environments

what is stratification?

layering or bedding

what is the most obvious feature of sedimentary rocks?

stratification

what is an arrangement of beds where on layer is inclined?

cross bedding

what happens to a sediments surface when wind or water moves across sand?

ripple marks

how are symmetric ripple marks produced?

waves

how do asymmetric ripples form?

unidirectional currents

where do asymmetric ripples form?

streams or rivers

what are all of the physical, chemical, biological, and geographic conditions that sediments are deposited?

depositional environments

what are environments at or near the transition between the land and the sea?

transitional depositional environments

what are examples of deltas?

mississippi and niger river

what delta is river dominated with a bird foot that elongates and has multiple bifurcations?

mississippi

what would happen to the mississippi delta if in a flood the river broke through a levee?

the flow would direct to the gulf of mexico

what do abandoned delta lobes not recieve?

sediment

what happens to abandoned delta lobes over time?

they degrade

what causes subsidence?

compaction

what is development on deltas at risk for?

subsidence

what allows subsidence to quicken?

sediment starvation

what does subsidence make deltas more vulnerable to?

flooding

what is an example of subsidence making a delta more vulnerable to flooding?

new orleans

what is a land area where all surface water from rain or ice converges to a single point at a lower elevation?

drainage basin

what is more common in high mountains and polar regions?

glacial environments

what environment has wind blown well sorted sand?

sand dune

how does the sand in dunes move?

to the prevailing winds

what environment results in uniform sandstones with gigantic cross beds?

sand dune

true or false: each depositional environment grades laterally into other depositional environments

true

what is a sea level drop called?

regression

what produces a coarsening upward sequence of facies?

regression

true or false: in a regression coarser grained (shallow water) facies underlie finer grained (deeper water facies)

false

what is this an example of?

sediment during a regression

what does the buildup of ice in the polar ice caps cause?

regression

what does localized uplift of the land in coastal areas cause?

regression

what is a sea level rise called?

transgression

what produces a fining upward (deepening upward) sequence of facies?

transgression

true or false: in a transgression finer grained (deeper water) facies overlie coarser grained (shallower water) facies

true

what is this an example of?

sedimentation during a transgression

what does the melting of polar ice caps cause?

transgressions

what does displacement of ocean water from underwater volcanos cause?

transgression

what does localized sinking or subsidence of the land in coastal areas cause?

transgression

what are surfaces that represent a gap in the geologic record because of erosion of nondeposition?

unconformable contacts

what is this an example of

angular unconformity

what is this an example of?

nonconformity

what is this an example of?

disconformity

what forces produce mountain belts?

tectonic

what provides vivid evidence of tectonic activity?

mountains

what occurs frequently in elongate, linear belts?

mountains

what is mountain building process called?

orogenesis

what type of mountain building has simple oceanic subduction beneath a continent?

andean

what type of mountain building has a collision with a continent?

collisional

what type of mountain building has slivers of oceanic lithosphere?

collisional

what geologic structure is generated by the tectonic forces originated by tectonic plate interactions at plate boundaries?

crustal deformation

what is this an example of?

deformed rocks

what is this an example of?

undeformed rocks

what causes rocks to deform?

stress and strain

what is confining pressure (uniform pressure in all directions) that produces no deformation?

stress

what is compressional stress?

squeezing

what is tensional stress?

pulling apart

what is shear stress?

sliding past

what is this an example of?

rock changes from stress

what does ductile mean?

bendable

what does brittle mean?

breakable

where is confining pressure and temperature low?

lithosphere and upper crust

what is the composition of rocks at the lithosphere/upper crust?

brittle

what happens when rocks in the lithosphere/upper crust deform?

fracture/fault

where is confining pressure and temperature high?

greater depth

what is the composition of rocks at greater depth?

ductile

how do rocks at greater depth deform?

flowing or folding

what deformation is the fold strain structure?

ductile

what deformation is the fault strain structure?

brittle

what deformation is the joint strain structure?

brittle

what is this an example of?

fold

what is this an example of?

fault

what is this an example of?

joints or fractures

why are folds and faults important?

natural resources

what is it called when rocks are bent into a series of wavelike undulations during mountain building?

folds

what do most folds result from?

compressional stress