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239 Cards in this Set
- Front
- Back
Loose, solid particles of minerals/rocks that originate from weathering and erosion of preexisting rocks or from precipitation from solution in water
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sediment
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What are the main sediment size fractions from smallest to largest
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clay,silt,sand,pebble,cobble,pebble
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The grinding away of sharp edges and corners of rock fragments during transportation
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rounding
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The process by which sediment grains are selected and separated according to grain size by the agents of transportation , especially by running water
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sorting
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Processes that convert loose sediment into sedimentary rock
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lithification
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A sedimentary rock that consists of sediment grains bound by cement into a rigid framework is said to have a ______ _______
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clastic texture
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The development and growth of crystals by precipitation from solution at or near earth's surface
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crystallization
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Rocks that have an arrangement of interlocking crystals that develops as crystals grow and interfere with each other are said to have a ______ _______
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crystalline texture
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When sediment grains are packed closer together as the weight of sediments increases with deeper burial
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compaction
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When minerals precipitate from water moving through the pore space between sediments and cement the grains together producing a solid rock
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cementation
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What are the 3 main sedimentary rock types:
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clastic, chemical, organic
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Sedimentary rock that forms from gragments of preexisting rocks
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clastic
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Sedimentary rocks that form from minerals thjat have precipitated from water (mostly seawater)
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chemical
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Sedimentary rock composed of organice carbon compounds
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organic
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A clastic sedimentary rock that has angular clasts
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Breccia
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A clastic sedimentary rock that has rounded clasts
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Conglomerate
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3 clastic rocks consisting of fine-grained silt and clay-sized particles
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siltstone, mudstone, shale
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5 types of chemical sedimentary rocks:
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limestone, marl/chalk, chert, dolomite, evaporites
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Chemical sedimentary rock composed primarily of calcite and can be from biochemical processes, or through inorganic processes
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limestone
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Chemical sedimentary rock with very fine-grained bioclastic limestone that forms from accumulation of the remains of microscopic marine organisms
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marl/chalk
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Chemical sedimentary rock formed from silica either through accumulation of the remains of microscopic marine organisms that precipitate silica fom sea water to produce their skeletal structures, or replacement of parts of limestone rocks with silica from ground water ro produce _____ nodules
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chert
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Chemical sedimentary rock made of calcium magnesium carbonate that forms from replacement of part of the calcium in limestone with magnesium
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dolomite
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Chemical sedimentary rocl that forms by precipitation of minerals during evaporation of water, such as gypsum & rock salt
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evaporites
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An organic sedimentary rock that forms from compaction and heating of partially decayed plant material preserved on oxygen depleted environments such as peat bogs and swamps
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coal
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Features found within sedimentary rock
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sedimentary structure
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A sedimentary structure where layers form due to some change in sediment deposition
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bedding
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A sedimentary structure where most sediment deposited in water is deposited in near-horizontal layers
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principle of original horizontality
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A sedimentary structure where younger layers are deposited on top of older layers
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superposition
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A sedimentary structure where thinner inclined beds within a thicker bed of rock that form due to deposition of sand in water or air as migrating ripples and dunes
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cross-bedding
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A sedimentary structure that has a layer with a vertical change in particle size, usually getting finer toward the top of the bed, due to deposition of sediment from a turbidity current
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graded bedding
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A sedimentary structure with polygonal patterms of cracks formed due to dying mud
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much cracks
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A sedimentary structure that includes the preservation of ripples
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ripple marks
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A sedimentary structure that contains preservations of the remains of organisms or their imprints in sedimentary rock
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fossils and imprints
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Bodies of rock of considerable thickness with a regional extent large enough to be "mappable"
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sedimentary formations
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A sedimentary rock formed by the cementation of sand grains
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sandstone
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A sandstone in which more than 90% of the grains are quartz
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quartz sandstone
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A type of sandstone in which more than 15% of the rock's volume consists of fine-grained matrix
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graywacke
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A fine-grained sedimentary rock notable for its ability to split into layers
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shale
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The boundary surface between two diffferent rock types or ages of rocks
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contact
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The locality that eroded and provided the sediment is known as the _____ ____ of a sediment
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source area
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The _______ __ _______ of a sedimentary rock is determined by studying bed sequence, grain compostion and rounding, and sedimentary structures.
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environment of deposition
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Refers to the changes to rocks that take place in Earth's interior
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metamorphism
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Form from preexisting rock through the processes of metamorphism wqhich result from heat and/or pressure conditions which cause changes to the texture and/or composition of minerals in the rock
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metamorphic rock
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Metamorphic changes occur to the rock in the _____-_____
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solid-state
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Metamorphic ______ form as minerals recrystallize or new minerals form under high pressure conditions
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fabrics
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Minerals that are unstable at high temperatures and pressures will reack to produce new ________ that are stable at these conditions
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minerals
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5 factors controlling metamorphic characteristics:
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composition of parent rock, temperature, pressure, fluids, time
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Using the starting material to provide large control on what type of metamorphic rock is produced
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composition of parent rock
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High _______ contribute to metamorphic reactions
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temperatures
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High ________ contribute to recrystallization amd development of fabrics
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pressures
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_______ help accelerate exchange of ions and speed metamorphic processes
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fluids
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Long periods of _____ are required for most metamorphic processes
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time
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Form from preexisting rock through the processes of metamorphism wqhich result from heat and/or pressure conditions which cause changes to the texture and/or composition of minerals in the rock
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metamorphic rock
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Metamorphic changes occur to the rock in the _____-_____
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solid-state
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Metamorphic ______ form as minerals recrystallize or new minerals form under high pressure conditions
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fabrics
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Minerals that are unstable at high temperatures and pressures will reack to produce new ________ that are stable at these conditions
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minerals
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5 factors controlling metamorphic characteristics:
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composition of parent rock, temperature, pressure, fluids, time
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Using the starting material to provide large control on what type of metamorphic rock is produced
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composition of parent rock
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High _______ contribute to metamorphic reactions
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temperatures
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High ________ contribute to recrystallization amd development of fabrics
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pressures
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_______ help accelerate exchange of ions and speed metamorphic processes
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fluids
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Long periods of _____ are required for most metamorphic processes
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time
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A strong confining pressure (acting the same in all directions) due to the weight of the overlying rocks
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lithostatic stress
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Pressure not the same in all directions, and leads to the development of planar fabrics known as foliation
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differential stress
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A type of differential stress where rock is compressed greater in one direction, usually due to tectonic forces
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compressive stress
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A type of differential stress where rock is sheared, commonly seen in fault zones, where rocks are sliding past each other
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shear stress
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3 types of non-foliated metamorphic rock:
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marble, quartzite, hornfels
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4 types of foliated metamorphic rock from increasing metamorphic grade:
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slate, phyllite, schist, gneiss
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6 types and characteristics of metamorphic environments
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contact, regional, shock, hydrothermal, metamorphic grade, relationship to tectonics
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Type of metamorphic environment; High temperature with differential stress in small areas surrounding magma bodies--produces non-foliated metamorphic environments
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Contact
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Type of metamorphic environment; Large areas exposed to high temperatures and large differential stresses associated with tectonic motions (convergent plate boundaries)
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Regional
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Type of metamorphic environment; Very high pressures resulting from impact of asteroids or comets
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Shock
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Type of metamorphic environment; Circulation of fluids near magma bodies or deep within the earth, produces ihydrothermally altered rocks
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Hydrothermal
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Type of metamorphic environment; Higher metamorphic grade means rocks formed at higher temperatures and or pressures, prograde metamorphism means increasing grade with deeper burial, retrograde, metamorphism refers to decreasing grade with decreasing depth (not seen as much due to loss of water)
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Metamorphic grade
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Type of metamorphic environments; regional metamorphism associated with convergent plate boundaries; depressed isotherms in subduction zones leads to high pressure, low temperatures metamorphic rocks (green schists/blueschists
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Relationship to tectonics
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Relationship to process and rate
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Uniformitarianism
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6 principles of relative time
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- contacts and formations
- original horizontality - superposition - lateral continuity - cross cutting relationships - inclusions |
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Principle of relative time; sedimentary rocks initially form in horizontal layers
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Original horizontality
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Principle of relative time; younger sedimentary rocks are on top of older sedimentary rocks
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Superposition
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Principle of relative time; sedimentary rock layers extend until they thin at edges
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Lateral continuity
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Principle of relative time; younger rocks/features cut across fabrics or layering features
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Cross-cutting relationships
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Principle of relative time; part of country rocks included within intrusive bodies are older than the intrusion
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Inclusions
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Contact that represents a significant gap in the geologic record with the rock unit above being considerably younger than the unit below
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Unconformities
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Types of unconformities
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- disconformity
- angular unconformity - nonconformity |
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Unconformity betwee parallel sedimentary layers-- can be difficult to detect-- need to examine fossil record
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Disconformity
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Unconformity between sedimentary layers with different bedding orients (usually inclined beds beneath near-horizontal layers above)
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Angular unconformity
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Unconformity between sedimentary layers sitting on top of older metamorphic or igneous rocks
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Nonconformity
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principles and use in relative dating
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correlation
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can trace a particular formation continuously
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physical continuity
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fossils change in predictable manner over geologic time
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faunal succession
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fossils from short-lived wide-spread species
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index fossils
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groups of fossils from species that coexisted can be diagnostic of a particular geological time
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fossil assemblages
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standard geological time scale
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-eras
-periods -epochs |
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loss of alpha particle consisting of two protons and two neutrons
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alpha decay
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loss of an electron from a neutron to produce a proton
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beta decay
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capture of an electron by a proton to produce a neutron
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electron capture
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refers to amount of time required for half of existing parent isotope to decay to daughter product, is constant for a given radioactive isotope
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half-life
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classification of processes of mass wasting
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-rate of movement
-type of material -type of movement |
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classification process; cm/yr (creep) to 100's of km/hr (rockfalls, rockslides, debris avalanches
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rate of movement
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classification process; consolidated (bedrock) or unconsolidated material
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type of material
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classification process; fall, slide, flow
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type of movement
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major divisions of mass wasting movement
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-flow
-fall -slide |
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division of mass wasting movement; moves like viscous fluid
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flow
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division of mass wasting movement; material falls down a cliff
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fall
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division of mass wasting movement; material remains relatively intact, sliding along a surface
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slide
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two types of the slide division of mass wasting movement
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-rotational
-translational |
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type of slide division; material slides along a curved surface
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rotational (slumps)
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type of slide division; material slides along a planar surface
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translational
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factors that control mass wasting
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-gravity
-water |
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types of gravity
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-shear force
-shear strength -normal force |
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type of gravity; role in block sliding: component of gravitational force parallel to slope in downslope direction
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shear force
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type of gravity; role in debris/earth flows: resistance to downslope movement through friction between soil particles
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shear strength
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type of gravity; component of gravity acting perpendicular to slop; increases friction
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normal force
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factor controlling mass wasting; some ___ adds stability due to surface tension effects, but excessive amounts reduces friction between particles and can increase likelihood of mass wasting
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water
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common types of mass wasting
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-creep
-flows -rockfalls and rockslides -debris slides |
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type of mass wasting; very slow downslope motion of soils, due primarily to freeze/thaw cycles
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creep
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type of flow types of mass wasting
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-earthflow
-solifluction -mudflow -debris flow/avalanche |
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type of flow; flow of soils downslope
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earthflow
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type of slow; downslope motion of water saturated soils over frozen subsoil
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solifluction/permafrost
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type of flow; loose material with lots of water flowing downslope--often channelized
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mudflow
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type of flow; less water than mudflow and larger material s
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debris flow/avalanche
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type of mass wasting; coherent blocks of bedrock falling or sliding downslope
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rockfalls and rockslides
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type of mass wasting; unconsolidated materials falling or sliding downslope
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debris slides and falls
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factors that enhance or mitigate mass wasting
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-undercut slopes
-vegetation removal -mass redistribution -role of water |
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factor that enhances or mitigates mass wasting; destabilizes slope above
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undercut slopes
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factor that enhances or mitigates mass wasting; increases likelihood of mass wasting
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vegetation removal
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factor that enhances or mitigates mass wasting; adding weight can increase likelihood of mass wasting
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mass redistribution
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-driven by solar energy and gravity
-atmospheric processes (evaporation, transpiration, condensation, precipitation) -ground and surface water processes |
hydrologic cycle
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water stays on surface and moves downslope
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runoff
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water moves into ground water system
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infiltration/percolation
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regions drained by streams and their tributaries
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drainage basins
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separate drainage basins flowing east vs. those flowing west (in North America)
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continental divides
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highpoints that separate drainage basins
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local divides
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typical drainage patterns
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-dendritic
-radial -rectangular -trellis |
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type of drainage pattern; tree-like shaped tributary systems- form where bedrock is of uniform lithology
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dendritic
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type of drainage pattern; streams flowing outward from central high point or inward to central basin
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radial
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typical drainage pattern; streams follow rectangular patterns of fractures in bedrock
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rectangular
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type of drainage pattern; major stream branches follow valleys underlain by weak rocks with smaller tributaries draining ridges underlain by more resistant rocks
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trellis
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factors controlling stream erosion and deposition
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-velocity cross section
-velocity vs. grain size diagram -gradient -channel shape and roughness -discharge |
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factors controlling stream erosion and deposition; highest velocities near center of channel below surface in straight reaches
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velocity cross sections
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factor controlling stream erosion and deposition; steeper gradients mean higher velocities
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gradient
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factor controlling stream erosion and deposition; smooth narrow deep channels have reduced surface drag along channel bed and banks and have higher velocities
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channel shape and roughness
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factor controlling stream erosion and deposition; volume of water moving past a given point in a given time; equals stream width x stream depth x stream velocity
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discharge
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action of water on bedrock that leads to erosion: eddy formation, plucking, and abrasion; rapids, cascades, and waterfalls are places where hydraulic action is particularly effective
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hydraulic action mechanisms
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stream transportations
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-sediment load
-bed load mechanisms |
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types of sediment load
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-bed load
-suspended load -dissolved load |
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type of sediment load; larger particles (sand-sized and up)
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bed load
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type of sediment load; fine grained particles (silt and clay-sized)
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suspended load
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type of sediment load; ions that go into solution (such as dissolution of calcite)
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dissolved load
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type of bed load mechanisms
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-traction
-saltation |
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type of bed load mechanism; rolling and sliding (larger gravel-sized particles)
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traction
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type of bed load mechanism; sand-sized particles move by hopping or skipping along the bottom
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saltation
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types of stream deposition
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-bars
-braided streams -meandering streams and point bars |
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type of stream deposition; location and evolution; deposits of sand or gravel sized particles in lower velocity parts of streams
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bars
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type of stream deposition; streams with large sediment supplies that form lots of bars with many channels in between
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braided streams
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type of stream deposition; higher velocities on outside of meanders (bends in the channel) leads to erosion of cut banks
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meandering streams and point bars
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flat areas around active stream channels that are inundated during flooding events
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flood plains
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evolution of meanders leads to cut-off abandonded old parts of the channels
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meander loops and oxbow lakes
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during flooding, larger sediments are deposited along the banks of the channel forming natural levees
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natural levees and flood stage
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cone or fan shaped deposits where streams exit steep mountainous canyons
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alluvial fans
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shorter lag times and higher peaks in runoff following rain events
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urbanization effects
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as streams mature, they produce smooth concave upward profiles
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graded stream concept
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relationship to bedrock geology and tectonics
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fluvial geomorphology
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old floodplain deposits let high as streams downcut through their own floodplains
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stream terraces
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rapid uplift of a region and downcutting of streams can lead to incised meanders
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incised meanders
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T/F Relative time refers to the time sequence in which events take place rather than the number of years?
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True
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T/F Creep is more active where freeze and thaw cycles occur each year?
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True
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T/F Graded bedding exhibits a vertical change from coarse grains to fine grains that reflect falling energy of transportation?
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True
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T/F Caves most commonly form from quartzites?
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False
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T/F Particle size is the primary basis from distinguished among various detrial sed. rocks?
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True
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T/F Chemical weathering is most effective in cold, dry climate?
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False
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T/F The water table marks the upper boundary of the saturated zone?
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True
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T/F Shale usually makes a food aquifer?
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False
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T/F Deltas form at the mouths of rivers as they flow into larger bodies of water b/c of the velocity of the water slows down and deposition occurs?
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True
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T/F Compaction and cementation are two common processes of lithification?
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True
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T/F Creep is more active where freeze thaw cycles occur each year?
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True
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T/F Sediments that form a breccia have been transported far from the source.
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False
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T/F Limestone is a detrital sedimentary rock composed mostly of gypsum
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False
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T/F The maximum velocity of water flowing in a stream channel is near the inside of curves in the channel
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False
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T/F Differential stress is a strong confining pressure that is equal in all directions.
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False
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T/F If rock A cuts across layering in rock B, rock A is older than rock B
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False
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T/F The amount of daughter product decreases as a parent isotope decays
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False
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(multiple choice) In the meandering stream, which of the following describes the relationship of erosion and deposition?
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Erosion on outside of meaner loop, deposition on inside
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(multiple choice) Geological processes operating at present are the same processes that have operated in the past principle of?
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uniformitarism
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(multiple choice) Not mechanical weathering?
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oxidation
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(multiple choice) Metamorphic rocks with a planar texture are said to be?
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foliated
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(multiple choice) A descending mass moving downslope as a viscous fluid?
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flow
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(multiple choice) A drainage pattern that resembles branches of a tree forms in regions of?
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dendritic
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(multiple choice) Porosity is?
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percentage of rocks volume that consists of openings
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(multiple choice) The resistance of movement or deformation of soil is its?
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shear strength
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(multiple choice) The degree of similarity in particle size in a sed. rock is referred to as?
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sorting
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(multiple choice) Which of the following is not a detrital sed. rock?
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chert
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(multiple choice) Ground water flows?
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from areas of high hydraulic head to low hydraulic head
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(multiple choice) You have 400 parent isotopes of radioactive material. After two half-lives, how much of the daughter product is there?
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300
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(multiple choice) "Within a sequence of undistributed sed. rocks, the layers get younger going from bottom to top" is the principle of?
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superposition
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(multiple choice) The soil horizon composed of organic matter mixed with minerals is the?
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horizon
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(multiple choice) The most common end products of the chemical weathering of feldspars are?
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clay minerals
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(multiple choice) The suspended load of a stream __________ .
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usually consists of fine sand, silt, and clay sized particles
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(multiple choice) Which of the following statements best describes the process known as creep?
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a slow downhill movement of soil or regolith
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(multiple choice) When water is pumped from a well, drawdown creates a __________.
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cone of depression
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(matching) A type of metamorphism associated with heat?
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contact
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(matching) A foliated low grade metamorphic rock?
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phylite
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(matching) A non foliated metamorphic rock?
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marble
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(matching) A foliated high grade metamorphic rock?
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gneiss
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(matching) A type of metamorphism associated with heat and differential stress?
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regional
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(matching) The youngest geologic era?
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cenozoic
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(matching) A nonfoliated metamorphic rock that forms from a parent rock of limestone?
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marble
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(matching) Raised sides of a steam channel?
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natural levee
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(matching) Accumulation of sediment on inside of meander?
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point bar
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(matching) Flat area of deposition adjacent to stream?
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flood plain
|
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(matching) Cone shaped body at mouth of canyon?
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alluvial fan
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(matching) Meander that has been cut off and isolated?
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ox bow
|
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(multiple choice) Which is the oldest unit?
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M (B intrudes into)
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(multiple choice) What principle allows you to decide that B is younger than D?
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cross-cutting relationships
|
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(multiple choice) Which of the following best describes the type of mass wasting known as slump?
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slippage of a mass of material as a unit along a curved surface
|
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T/F Graded bedding exhibits a vertical change from coarse grains at the bottom to fine grains at the top that reflects falling energy to transposition within turbidity current?
|
true
|
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The oldest geologic era of panerozoic?
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paleozoic
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(matching) A type of mechanical weathering that results in the formation of sheet joints in large bodies of exposed intrusive ingeous rock?
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pressure release
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T/F The amount of daughter product increases as a percent isotope decays.
|
true
|
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(multiple choice) In transgression, deposition environments ________.
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migrate inland as relative sea level rises
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T/F Differential stress is a strong confining pressure that is equal in all directions.
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False
|
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T/F Current estimates obtained from dating of meteorites indicate the earth is 3.55 billion years old?
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False
|
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T/F Coal is classified as an organic sedimentary rock fomred from partially decayed plant material.
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True
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(multiple choice) A non-foliated metamorphic rock that forms from a parent rock of sandstone?
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quartzite
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T/F Evaporates are types of detrital sedimentary rock?
|
False
|
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(multiple choice) A schist that formed in a high pressure, low temperature environment probably formed _________.
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in a subduction
|
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T/F Chemical weathering rates are highest in cold, dry climates?
|
False
|
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T/F Mud cracks are an example of sedimentary structure that indicates exposure of fine grained sediments to air.
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True
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Metamorphic rocks without a planar texture are said to be?
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non-foliated
|
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T/F Spheroidal weathering results from different rates of weathering from different rock types.
|
False
|
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T/F Particle size is the primary basis for distinguishing among various detrital sedimentary rocks and generally decreases with increasing distance of transportation.
|
True
|
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The 3 types of sedimentary rocks
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detrital,chemical, organic
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A type of mass wasting that is often related to permafrost is?
|
solifluction
|
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T/F The veriety of metamorphic rock that indicates retrograde metamorphic is likely the result of the absence of water following peak metamorphic temperatures and pressures.
|
True
|
|
If you start with 12,000 parent isotopes of radioactive material, after 2 half-lives, how much of the parent isotopes remains?
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3000
|
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T/F Daily cycles of freezing and thawing may contribute significantly to creep.
|
true
|
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Rocks composed of the mineral calcite are subject to this hemical weathering process
|
dissolation
|
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T/F Silt grains are the smallest size in detrital sediment particles
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false
|
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Abundant fossils of complex organisms begin to appear?
|
544 million years ago
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