Geology Chapter Final 20 MG – Flashcards
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Which of the following correctly describes the Atlantic and Pacific continental margins?
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The Atlantic is a passive margin, and the Pacific is an active margin.
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Choose the true statement regarding the continental shelf.
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The shelf represents the flooded portions of continents.
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Turbidity currents travel from the shelf through _____, creating deep sea fans.
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canyons
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If the subduction angle is steep, the overriding plate may undergo _____.
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subduction erosion
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Which of the following is true regarding shallow subduction angles?
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Sediment and seamounts are scraped from the downgoing plate to produce an accretionary wedge.
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What happens as plate diverge at an oceanic ridge?
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New oceanic crust and lithosphereic mangle are generated by the cooling of molten rock upwelling from the mantle.
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What two layers of the ophiolite sequence are compositionally similar, but formed in different areas with respect to the crust?
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pillow lavas and gabbro
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Which of the following contains the entire ophiolite suite, in order from the mantle to the seafloor?
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mantle peridotite, gabbro, sheeted dike complex, pillow lavas, deep-sea sedimets
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What are the features associated with a divergent boundary that is spreading quickly?
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a relatively smooth swell with gentle slopes.
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Which of the following accurately compares the Mid-Atlantic Ridge and East Pacific Rise?
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The Mid-Atlantic Ridge is spreading at a much slower rate than the East Pacific Rise.
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Name the correct order of rifting events.
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crustal upwarp, rift valle, linear sea, ocean
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The Gulf of Aden represents which part of the rifting sequence?
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linear sea
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The timing of _____ and continental breakup strongly correlate.
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flood basalt formation
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What feature connects the South American Paraná and African Entedeke flood basalts?
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seamount chains
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What sequence of rocks would you expect rift valley evolution to produce, from oldest to youngest?
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volcanic rocks, clastic sedimentary rocks, deep sea sedimentary rocks
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Which of the following is a true statement regarding the Farallon Plate?
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It was an oceanic plate that used to exist between the Pacific and North American Plates.
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The plate boundary in the U.S. Pacific Northwest is _____, while most of the California coast if characterized by a _____ plate boundary.
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convergent; transform
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Which statement regarding Baja Mexico and the city of Los Angeles is correct?
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Both are located on the Pacific Plate.
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Strike-slip faulting of the Queen Charlotte and San Andreas fault systems shoes _____.
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a right lateral sense of motion
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What happened to the Farallon Plate approximately 20 million years ago?
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The San Andreas and Queen Charlotte Faults were established where it was subducted beneath the North American plate
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Which of the following scenarios could result in the development of a compressional mountain belt?
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two landmasses collide
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Which geologic features would be present in compressional mountain belts?
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thrust faults, intrusive igneous rocks, folds
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Which of the following rocks are characteristic of compressional mountain building?
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schist
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Which of the following orogenies helped to create the Appalachian Mountains?
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Taconic, Acadian, and Alleghanian
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Which event marked the creation of the supercontinent Pangaea?
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The lapetus Ocean closed during the Alleghanian Orogeny.
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Which of the following geographic provinces is the newest addition to the North American continent?
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Coastal Plain
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Which mountain range marks the boundary between the Indian and Eurasian Plates?
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Himalayas
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What kind of tectonic boundary is currently responsible for creating the Himalayas?
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Continent-Continenet Convergent Boundary
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What geologic features were created in the Eurasian Plate when India underthrust beneath it?
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thicker continental crust, thrust faults
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As India moves northward, Cina and Southeast Asia are being relocated tot he east and southeast because of "escape tectonics." What feature is allowing them to "escape"?
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stike-slip faults
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When the Indian Plate collided with Eurasian Plate, why didn't it subduct?
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The Indian Plate is too buoyant. The Indian Plate is too thick.
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A terrane is _____.
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a mass of rock that formed elsewhere and was added to a continent
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Which tectonic boundary is associated with the addition of terranes to a continent?
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convergent boundary
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What is the name of the process by which terranes are added to continents?
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accretion
