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72 Cards in this Set
- Front
- Back
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besides frost wedging, which of the following are examples of mechanical weathering?
-bioturbation -spalling of boulders from range fires -oxidation in biotite |
-spalling of boulders from range fires
-oxidation in biotite |
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H+ ions utilized in hyrdolysis weathering reactions come from
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carbonic acid
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over time angular joints will___due to surface weathering
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-become more angular
-become... |
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frost wedging occurs in rocks because
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water expands when it freezes to form ice
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joints facilitate weathering because
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-permit water and other chemical agents to penetrate below surface area
-provide more surface area for the weathering front to attack |
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why did the depth of rilling increase on the limestone boulders deposited on three glacial moraines?
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-the older moraine was older and subjected to more weathering
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limestone will tend to precipitate in sea water when
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carbon dioxide content decreases
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which of the following transport agents usually result in crossbeds?
-wind -turbidity currents -rivers -glaciers |
-wind
-glaciers |
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what test could conclusively tell you that marble and limestone are both comprised of the mineral calcite?
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-reaction with HCl acid
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chert generally precipitates in deep ocean water because
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calcium carbonate precipitates in cold water
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monocline folds result from
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uni-directional stresses
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oolites form from
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precipitation of calcite around sand grains oscillated by waves
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pillow basalts form when basalt is
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erupted into water
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if a fault offset a volcanic layer of ash 15000 years old and was buried by a landslide deposit that was radiocarbon dated at 12000 years, one can incur that the faulting event is
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-occurred prior to 12000 years, occurred after 150000 years
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according to the principle of inclusions the closest constraining age for the formation of conglomerate rock
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would be oldest clast (pebble) age comprising the conglomerate rock
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how might you recognize in the field that a disconformity of rock exists between two sequences of rock?
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-buried soil or weathering zone between two units
-fossil assemblages that are not temporarily compatible between the two units |
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the strike slip fault shown below is
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right lateral
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how can geologists determine the source volcano of a dated ash layer in several local lake cores?
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-the ash layer will thicken in the lake cores closest to the source volcano
-the grain size in the ash layer will increase in the lakes core closest to the source volcano |
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radiocarbon dating is most useful
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for dating organic matters less than 50000 years old
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where is radiocarbon first produced on earth?
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in the atmosphere
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a minimum of___seismic stations are necessary to determine the focus of an earthquake
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3
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if an earthquake occurs, the ____ waves are the last to arrive at the seismic station
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S
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a volcanic neck is formed___and the surrounding rock erodes away
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when a magma body solidifies within the vent of a volcano
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high temperature is conducive to___deformation in rock
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ductil?
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a high strain rate is conducive to___deformation in rock
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brittle fracture
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according to the national earthquake hazard map, the PS region is a ___risk region of the nation
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high
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the____is expose in the center of an eroding anticline
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oldest rock
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a reverse fault
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-may have repeatedly strata exposed in a vertical cross-section
-may result in older rock units in a vertical cross section |
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____is an example of elastic rock deformation
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-an overturned fold
-filling and emptying a reservoir -isostatic unloading of the earth's lithosphere following deglaciation |
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which metamorphic rock has been subject to the lowest grade of heat and pressure?
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slate
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what kind of fault bound mountains and valleys of the Basin and Range province in Nevada and Utah
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normal faults
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what kind of stress would you expect to cause this type of faulting?
(normal fault) |
tensile
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at what kind of plate margin would you expect to find this type of fault?
(normal fault) |
divergent
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what type of hypothesis did we discuss to explain Basin and Range tectonics?
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the spreading ridge was subducted under Cali and is now under Nevada and Utah
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overturned fold may turn into
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thrust faults
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the stress rate___the strain rate for elastic deformation
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is proportional to
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where do earthquakes occur in the pacific northwest?
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-near the surface in the north american plate
-deep within the juan de fuca plate -at the cascadia subduction zone |
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the recurrence interval largecascadia subduction zone earthquakes is
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500 years
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how did geologists determine the exact day of offest of the cascadia subduction zone in 1700 AD
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they had accurate tsunami logs from japan that recorded this event
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as the northern great lakes isostatically rebound
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northern great lakes, hudson bay canada
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an overturned fold will often evolve into a____with continued compressive stress
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thrust fault
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a tubular intrusive body that is oriented parallel to the existing sedimentary strata
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is a sill
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the most recent eruption of mt st helens was___previous eruptions during the holocnee
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greater
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lahars generated from mt. rainier have
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flowed as far as tacoma in the last 5000 years
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a sedimentary rock united with graded beds that fine towards the top would indicate
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that the rock unit was upside down
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james hutton discovered
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-that the geologic processes operating today at the surface of the earth also operated in the past
-the principle of uniformintarianism |
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the lone survivor of the st. pierre nuee ardente was
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raouel sarteret
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what does the presence of geothite tell you about drainage conditions of soil?
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the soil is saturated at some point during the year
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a minimum of __ seismic stations is necessary to determine the focus of an earthquake
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3
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topset beds of a delta
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-are graded to the elevation of the lake or sea
-are deposited at the bottom of lake embayment |
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in order to relieve stress buildup that would relieve a magnitude 7 earthquake, how many mag 5 earthquakes would have to occur?
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900?
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which plate boundaries tend to have the deepest focused earthquakes?
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divergent
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plutons may be composed of ___igeneous rock
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-felsic composition
-intermediate composition -mafic composition |
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as soils age
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-the horizons get thicker
-the profile gets redder -clay content with soil profile increases |
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which of the following depositional events generally results in graded beds?
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rivers
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over time angular joint blocks will become____due to surface weathering
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rounded
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what diagnostic property would you use to determine that the cementing agent within sandstone is Fe2O3
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its reddish color
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river erosion tends to be greatest_____of fold structure
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near the axis
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the zig zag pattern of rock units that can be observed while flying over pennsylvania
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erosion of plunging (tiltied) anaclines and synaclines
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which of the following transport agents generally results in oscillation?
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ocean waves
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according to the principle of cross-cutting relationships, if a fault is found cutting across a sedimentary strata, the reasonable conclusion would be that
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the fault is younger than the strata
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the effusive eruptions on Iceland
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-are composed of basaltic composition lava
-largely destroy many structures without many fatalities |
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which metamorphic rock has been subject to the highest grade of heat and pressure
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gneiss
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why is quartz the most common mineral found on beaches in Puget Sounds
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quartz is lighter than all other minerals and can be washed up by waves
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clastic sedimentary rocks are subdivided
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based on grain size of the constituent clasts
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what is his fav color?
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yellow
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why was he late on march 10
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uploading presentation
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Fri Feb 5th guest speakers:
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gerard roe and nichole frenkes
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protero zoic
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1.1 billion years ago was the one time we have recorded as an ice age
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why was he late on march 5?
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had to print imax tickets
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43 million years ago
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Kola Pacific Spreading Ridge WA subducted under Alaska, changing plate direction
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Why did Diosaurs go extinct/ how
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Iridium Anomalies/ Shocked Corps
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