oceanography chapter 4 – Flashcards
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coccolithophores
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biogenous sediment
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halite
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hydrogenous sediment
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metal sulfides
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hydrogenous sediment
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siliceous ooze
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biogenous sediment
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tektites
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cosmogenous sediment
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ice rafting
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associated with glacial deposits
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turbidite
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associated with submarine canyons and deep-sea alluvial fans
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siliceous ooze
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does not fit
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Describe the process of how a deep-sea drilling ship such as the JOIDES Resolution obtains core samples from the deep ocean floor.
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This ship has a tall metal drilling rig to conduct rotary drilling. The drill pipe is made up of individual sections that can be screwed together to make a single string of pipe. The drill bit, located at the end of the pipe string, rotates as it is pressed against the ocean bottom. A core can then be raised to the surface from inside the pipe
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The most abundant mineral in lithogenous sediments is
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quartz
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Sediments with all grains of about the same size are classified as
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well sorted
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Sediment that begins as rocks on continents or islands is called
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lithogenous (terrigenous) sediment
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Sediments that are poorly sorted were most likely deposited by
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a glacier
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Sediments derived from pre-existing rocks on land are called
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lithogenous
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Describe the origin, composition, texture, and distribution of lithogenous sediment
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-Lithogenous sediment is derived from pre-existing rock that is weathered and transported to the oceans by streams, wind, glaciers, and gravity from land. -The composition of lithogenous sediment reflects the material from which it was derived. -The size of the sediment particles is dependent on the energy needed to lay down the deposit, as well as its sorting. -Lithogenous sediment can be found nearly everywhere on the ocean floor
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difference between neritic and pelagic deposits
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Neritic (of the coast) deposits are found on continental shelves and in shallow water near islands; these deposits are generally coarse grained. Pelagic (of the sea) deposits are found in the deep-ocean basins and are typically finer-grained materials
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Oozes are uncommon on continental margins because
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the biogenous component tends to be overwhelmed by the amount of lithogenous material derived from the nearby continent
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calcium carbonate (CaCO3)
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foraminiferans
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Calcium carbonate is most likely to dissolve in water with which characteristics
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lots of carbon dioxide and colder temperatures
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oolites
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does not fit
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two major chemical compounds that comprise most biogenous sediment
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The two most common chemical compounds in biogenous sediment are calcium carbonate (produced by foraminifers and coccolithophores) and silica (produced by diatoms and radiolarians)
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Salt beds of the U.S. Gulf Coast are
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hydrogenous sediments
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All of the following are hydrogenous sediments except
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stromatolites
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The most likely place to find abundant manganese nodules is on the
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abyssal plain far from a continent
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tektites
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does not fit
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Sediments with an extraterrestrial origin are called
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cosmogenous
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The particles found in some sediment that suggests that an extraterrestrial impact event are
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tektites
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You take a sediment sample from the ocean floor at a depth of 5500 m. The area has low biological productivity and the CCD is at 4500 m depth. Your sample will probably consist of
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clay
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Sediments found on continental margins are called
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neritic
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Pelagic clays contain lots of material that settles to the seafloor through the water column and are
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less than 30% biogenous material
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All of the following are true concerning neritic sediment deposits except
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they are primarily composed of calcareous deposits of biological origin
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Which of the following is not an important control on oceanic sediment accumulation
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All of the above factors are important
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Ocean sediments provide all of the following mineral resources except
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coal
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where would you expect to find large amounts of lithogenous sediment
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-on the continental shelf
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Which of the following conditions allows for calcareous ooze to be found beneath the CCD
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The ooze accumulates above the CCD and then is covered before being transported to deeper depths by sea floor spreading
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responsible for the creation of siliceous ooze
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-Radiolarians
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considered hydrogenous
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-manganese nodules
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Marine sediments provide valuable clues about which of the following Earth history events
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-previous ocean circulation patterns
