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Cards In This Set
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What is viscosity?
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Viscosity is resistance to flow.
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How do metamorphic rocks form?
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Metamorphic rocks form when pre-existing rocks are subjected to heat and/or pressure.
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Describe the eruption of a shield volcano
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This eruption is relativley quiet due to the fluid nature of the magma. Low viscosity magma does not trap gases that lead to violent explosions.
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What is Pahoehoe lava?
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Pahoehoe lava is a relatively fluid lava (low viscosity) that is mafic in nature.
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What is mafic magma or lava?
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Mafic magma or lava has a high magnesium and iron content. This forms oceanic crust. It is low viscosity
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What is felsic magma or lava?
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Felsic magma or lava has a high feldspar and quartz (silicon dioxide) content. This forms continental crust. It is high viscosity.
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What type of rock does felsic magma form?
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Felsic magma forms the granitic igneous and metamorphic rock the of continental crust.
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What is a flood basalt?
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A flood basalt is a very large scale outpouring of mafic lava from fissures in the Earth's crust. It forms layers of basalt.Example:Columbia Plateau
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What is Aa lava?
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Aa lava is felsic lava generally found at composite volcanoes.
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What is subduction?
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Subduction occurs when one tectonic plate overridesa another. The plate at the bottom moves downward into the asthenosphere.
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What type of land feature can occur at subduction zones?
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Land features include island arcs such as Japan or the Aleutian Islands.
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What oceanic feature is found at subduction zones?
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Oceanic trenches are found at subductions zones.
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Describe a convergent boundary.
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Convergent boundaries occur when two tectonic plates move toward each other. The ycan colide or one can be subducted under another.
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Why do tectonic plates move?
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They move because of convection loops in the asthenosphere. Plates are "dragged" along by the movement of the currents in the asthenosphere.
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How does a ridge and valley mountain system form?
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This system forms as a result of compressional forces folding rock layers into a series of anticlines and synclines
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