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66 Cards in this Set
- Front
- Back
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What is meant by the term "size" in relation to to sediments?
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not uniquely defined, depends on measurement, sieve diameter, sedimentation diameter
Sedimentary textures |
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What is textural maturity? What processes produce textural maturity?
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degree to which it approaches end result, removal of clays, good sorting, roundness of grains
Sedimentary textures |
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Many sediments and sedimentary rocks show a preferred orientation of the particles. What are the causes and characteristics of tihs orientation in gravel, sands, and shales?
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elongate/flat particles, affects packing, imbrication, Qtz. high flow, mud-compaction
Sedimentary textures |
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Why are boundary values important?
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govern interaction of flow with sediment
Fluid Dynamics & sediment transport |
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What are the principal modes of sediment transport?
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traction, saltation
Fluid Dynamics & sediment transport |
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What processes operate to entertain sediement?
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.
Fluid Dynamics & sediment transport |
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The concept of hydraulic equivalence applies to the settling velocity of particles.
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two particles regardless of size/density etc. settle @...
Fluid Dynamics & sediment transport |
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What fluid properties are important in the entrainment of sediment?
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velocity and shear
Fluid Dynamics & sediment transport |
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What sediment properites are important in the entrainment of sediment?
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size and density
Fluid Dynamics & sediment transport |
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What are the modes in which sediment is transported?
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traction and saltation
Fluid Dynamics & sediment transport |
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How does a particle of sand become entrained and transported?
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no movement > random > moves some > all
Fluid Dynamics & sediment transport |
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How is the amount of sedimient moving as bedload of a river or beach calculated?
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it is the traction + saltation
Fluid Dynamics & sediment transport |
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How is the amount of sediment moving as suspended load calculated?
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it is impossible
Fluid Dynamics & sediment transport |
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Grading, is formed under what condition?
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turbidity currents
Sedimentary structures |
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Flute casts, is formed under what condition?
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erosion of mud by turbulent flow
Sedimentary structures |
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Ripple marks, under what conditions are they formed?
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.
Sedimentary structures |
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Tabular cross-bedding, under what conditions are they formed?
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migration of bed formed
Sedimentary structures |
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Trough cross-bedding, under what conditions are they formed?
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sinous/lunate dunes
Sedimentary structures |
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Parallel laminations, under what coniditions are they formed?
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.
Sedimentary structures |
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What in "flow regime"?
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interpretation of structures and sequence of structural, general strengh
Sedimentary structures |
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What can ripples tell you about the environment in which they were depostied?
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net accumulation
Sedimentary structures |
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What can dunes tell you about the environment in which they were deposited?
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High flow conditions
Sedimentary structures |
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What do "climbing ripples? indicate about the conditions in which they were deposited?
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high net accumulation
Sedimentary structures |
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What useful information do isopach maps provide?
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thickness, tectonic/during/erosion
Sedimentary methods |
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What useful information do structure contour maps provide?
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respects to datum, after deposition
Sedimentary methods |
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What useful information do cross sections provide?
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2 dimensional relationship emphasizes structure/stratigraphy
Sedimentary methods |
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What useful information do facies maps provide?
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description
Sedimentary methods |
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What useful information do fence diagrams provide?
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3d ...
Sedimentary methods |
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What is Walther's Laws?
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laterally adjacent, vertically succesion
Stratigraphic relationships |
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What is transgression/regression?
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sea level rise/fall
Stratigraphic relationships |
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How abundant are the gaps in the stratigraphic record?
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very
Stratigraphic relationships |
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What is a facies model?
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body of rock with specific characteristics - modern environments
Facies models |
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What are the componenets of a facies model?
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physical, biological, stratigraphic
Facies models |
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What are the sedimentologic and stratigraphic characteristics of meandering river deposits?
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least understood, channel ripples, point bar, fining upwards, migration, floods, low slope, vertical accretion
Facies models |
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What are the sedimentologic and stratigraphic characterics of aeolian dune deposits?
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cross bedding
Facies models |
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What are the sedimentologic and stratigraphic characterists of beach deposits?
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.
Facies models |
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What are the sedimentologic and stratigraphic characteristics of shallow marine deposits?
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.
Facies models |
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What are the sedimentologic and stratigraphic characteristics of submarine fan deposits?
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Facies Models |
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What is a lithostratigraphic unit?
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observable, lithic character/stratigraphic position
formation = widely recognizable characteristics Nomenclature |
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What is a chronostratigraphic unit?
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time rock, serve as physical reference for all rock formed at sometime, ex. system (Cambrian)
Nomenclature |
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What is a geochronologic unit?
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division of time based in rock record, ex. Period = System
Nomenclature |
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What is a biozone?
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fundamental unit of biostratigraphy, taxon zone
Nomenclature |
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What is the Law of Superposition?
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oldest layer is one the bottom
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Describe three types of lithologic boundaries.
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lithic change, unconformities, key beds, vertical grdations
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How are geologic units correlated?
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physical
1) walk out 2) mapping lithologies 3) tracing unformities Chronologic 1) biostratigraphy 2) time marker Correlation |
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Define diachronism, and give an example.
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not the same age everywhere
Correlation |
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What methods are used for geophysical correlation?
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a) wireline logs
b) seismic methods c) magnetostratigraphy Correlation |
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How can the absolute ages of period boundaries be determind?
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.
Correlation |
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Which method has better resolution, radiometric dating or biostratigraphy?
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all the same
Correlation |
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What is eustacy?
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changes in sea level
Correlation |
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What are the probable causes of large-scale, long-term changes in sea level?
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major plate interactions
Correlation |
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Parasequence
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conformable succession bounded by marine flooding or correlative surfaces
Correlation |
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Parasequence set
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stacking of parasequence, bounded by flooding, genetically related, depends on rate of sediment accumulation
Correlation |
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Sequence
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genetically related, conformable, conformities, or correlative surfaces
Correlation |
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What is the fundamental principle of sequence stratigraphy?
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Super position. Use surface to subdivide ...
Correlation |
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What is an ophiolite sequence? What is its significance?
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produced on spreading ocean flow, deep sea sediment, pillow basalt, gabbros, ultra mafics
Tectonics/Sedimentation/Stratigraphy |
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What are the stratigraphic and structural characteristics of subduction zones?
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collision, deformation, folding/faulting, submarine fans deposition, gravity slide
Tectonics/Sedimentation/Stratigraphy |
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What are the stratigraphic and structural characteristics of aulacogens?
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failure of part of sea floor spreading, subsidence and accumulation
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What are the stratigraphic and structural characteristics of continetal margin arcs?
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subduction/modern reef building
deformation of shallwo marine... abundant flysch sedimentation plutonism deformation back arc molasse depostion in back |
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What is a sedimentary basin?
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significant localized accumulation of sediment, significant subsidence,
foreland - denver, mountain building cratonic - williston, no connection with tectonics |
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What are two important weathering techniques?
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solution - dissolution evaporate
oxidation - reaction with oxygen, Fe/Su Weathering/Clay |
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Which of the common rock-forming minerals are least stable in a weathering environment?
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gypsum/calcite...
quartz hematite/goethite/zircon/rutile Weathering/Clay |
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What characteristics appear to control the stability of minerals during weathering?
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how close the ...equilibrium, move structure..weak surfaces = less stable
Weathering/Clay |
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How are clay minerals classified?
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structure
two layer = bound tightly three layer = expanding - SMETCTITE or none expanding- ILLITE Weathering/Clay |
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What are the basic structural components of clay minerals?
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tetrahedra
Weathering/Clay |
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What factors appear to control the type of clay minerals formed during weather?
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climate and weathering conditions, NOT SOURCE ROCK
Weather/Clay |
