Metamorphic Final

25 July 2022
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question
What is rock texture? the way a rock tastes the way a rock feels the way a rock looks the way a rock smells the way a rock sounds
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the way a rock looks
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How will minerals orient when a rock is put under normal stress? oblique to the direction of the greatest stress parallel to the direction of the greatest stress random to the direction of the greatest stress perpendicular to the direction of the greatest stress
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perpendicular to the direction of the greatest stress
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How will minerals grow when a rock is put under normal stress? oblique to the direction of the greatest stress parallel to the direction of the greatest stress random to the direction of the greatest stress perpendicular to the direction of the greatest stress
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perpendicular to the direction of the greatest stress
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How will minerals orient when a rock is put under shear stress? perpendicular to the direction of the shear stress oblique to the direction of the shear stress parallel to the direction of the shear stress random to the direction of the shear stress
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parallel to the direction of the shear stress
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Why do bands of minerals form when rocks are put under normal stress? Atoms dissolve, minerals migrate to new locations, and atoms reform. Minerals dissolve, atoms migrate to new locations, and minerals reform. Atoms migrate to new locations, and minerals reform. Minerals migrate to new locations, and atoms reform.
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Minerals dissolve, atoms migrate to new locations, and minerals reform.
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Why are mineral bands in metamorphic rocks light and dark colored? Light minerals rich in iron and magnesium separate from dark minerals rich in silica and aluminum. Light minerals rich in iron and silica separate from dark minerals rich in magnesium and aluminum. Dark minerals rich in iron and magnesium separate from light minerals rich in silica and aluminum. Dark minerals rich in silica and magnesium separate from light minerals rich in iron and aluminum.
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Dark minerals rich in iron and magnesium separate from light minerals rich in silica and aluminum.
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Which processes result in mineral flattening during metamorphism? deposition followed by crystallization dissolution followed by crystallization crystallization followed by deposition crystallization followed by dissolution
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dissolution followed by crystallization
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When fine-grained tabular minerals in a rock at depth are subjected to differential stresses, they _________. Hints melt rapidly weather quickly align perpendicularly to the plane in which the maximum compressive stress is applied align parallel to the plane in which the maximum compressive stress is applied
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align perpendicularly to the plane in which the maximum compressive stress is applied
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________ is the process by which new mineral grains larger than the original mineral grains form as a result of metamorphic heat. Foliation Metasomatism Dissolution Recrystallization
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Recrystallization
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Which of the following best describes the difference between differential stress and confining pressure? Hints In differential stress, the stresses on the sides are greater than the force of gravity. Stresses are the same on all sides for confining pressure. In confining stress, the force of gravity is higher than in differential stress. Both confining pressure and differential stress have stresses applied to a rock in one direction, which is greater than the force of gravity as a whole. Under confining pressures, the stresses on the sides are greater than the force of gravity. Stresses are the same on all sides for differential stress. In differential stress, the force of gravity is higher than in confining stress.
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In differential stress, the stresses on the sides are greater than the force of gravity. Stresses are the same on all sides for confining pressure.
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Which of the following describes the orientation of the long axes of rocks and mineral grains in relationship to the stress applied? Choose all that apply. Hints Mineral grains are oriented parallel to the direction of the weakest stress applied. Mineral grains are oriented parallel to the direction of the strongest stress applied. The long axis of a rock is parallel to the direction of the weakest stress applied. The long axis of a rock is oriented parallel to the direction of the strongest stress applied.
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-Mineral grains are oriented parallel to the direction of the weakest stress applied. -The long axis of a rock is parallel to the direction of the weakest stress applied.
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What is the most important factor driving metamorphism? Hints Type of parent material Differential stress Chemically active fluids Heat Confining pressure
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heat
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What do we call a metamorphic rock that has microscopic to very fine-grained texture, breaks into slabs or sheets and is dull on the surface? Hints slate phyllite garnet mica schist gneiss mica schist
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slate
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What do we call a metamorphic rock that has a coarse-grained texture, is dominated by mica, and contains no other notable minerals? Hints garnet mica schist slate mica schist phyllite gneiss
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mica schist
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What do we call a metamorphic rock that has coarse-grained texture, minimal amounts of mica, and contains minerals that are segregated into bands? Hints garnet mica schist slate phyllite gneiss mica schist
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gneiss
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Working in the field, you encounter a metamorphic rock that lacks foliation and reacts to hydrochloric acid. How should this rock be classified? Hints quartzite marble anthracite coal mica schist stretched-pebble conglomerate
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marble
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Working in the field, you encounter a metamorphic rock that lacks foliation and is composed primarily of interlocking sand-sized grains that will scratch glass. How should this rock be classified? Hints marble stretched-pebble conglomerate quartzite anthracite coal mica schist
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quartzite
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Which of the following is the parent rock of quartzite? Sandstone Granite Limestone conglomerate
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sandstone
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What is the definition of a parent rock? The rock that was altered by metamorphism The rock produced by metamorphism The igneous rock forming through solidification of magma The resulting precipitate when water dissolves mineral matter
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The rock that was altered by metamorphism
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What is the most efficient agent of metamorphism? Hints heat weathering pressure chemically active fluids cementation
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heat
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Contact metamorphism takes place when rocks _____. Hints come in contact with a magma body are quickly weathered are rapidly lithified are rapidly melted are dragged down deep into Earth
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come in contact with a magma body
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In addition to temperature, which of the following agents increases with depth in Earth? Hints cementation erosion weathering hardness pressure
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pressure
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When fine-grained tabular minerals in a rock at depth are subjected to differential stresses, they _________. Hints melt rapidly weather quickly align perpendicularly to the plane in which the maximum compressive stress is applied align parallel to the plane in which the maximum compressive stress is applied fracture
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align perpendicularly to the plane in which the maximum compressive stress is applied
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At a mid-ocean spreading center, alteration of rocks by chemically active fluids causes metamorphism by __________. Hints melting the pre-existing rock changing the pressure on the pre-existing rock "baking" the pre-existing rock weathering of the pre-existing rock replacement or substitution of ions in the pre-existing rock.
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replacement or substitution of ions in the pre-existing rock.
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Which of the following factors describe the metamorphic conditions at a mid-ocean ridge? Choose all that apply. Hints high mantle temperatures hot, watery fluids high pressure low temperature low pressure
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-hot, watery fluids -low temperature -low pressure
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Which of the following factors describe the metamorphic conditions in a subduction zone? Choose all that apply. Hints high temperature hot, watery fluids high pressure low temperature low pressure
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high pressure low temperature
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Which of the following is a metamorphic rock? Hints granite shale chlorite sandstone gneiss
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gneiss
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Which of the following is a temperature associated with metamorphism? Hints 900 degrees Celsius 1500 degrees Celsius 150 degrees Celsius 400 degrees Celsius 50 degrees Celsius
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400 degree celsius
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Which of the following rocks represents the highest grade of metamorphism? Quartzite Gneiss Phyllite Biotite schist
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gneiss
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How are metamorphic rocks formed? Preexisting sediment is altered through melting and pressure. Preexisting rock is altered through heat and pressure. Preexisting rock is altered through melting and pressure. Preexisting sediment is altered through heat and pressure.
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Preexisting rock is altered through heat and pressure.
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Do metamorphic rocks look like the preexisting rock from which they form? sometimes, but not always never almost always rarely often
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sometimes, but not always
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What is foliation? fracturing in metamorphic rocks that results from the reorientation of minerals fracturing in sedimentary rocks that results from the reorientation of minerals banding in metamorphic rocks that results from the reorientation of minerals banding in sedimentary rocks that results from the reorientation of minerals
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banding in metamorphic rocks that results from the reorientation of minerals
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How will foliation in continental metamorphic rocks formed during subduction be oriented? oblique to the direction of plate movement parallel to the direction of plate movement perpendicular to the direction of plate movement
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perpendicular to the direction of plate movement
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What would you call a granite that has undergone metamorphism and now exhibits foliation? lava basalt limestone gneiss granite
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gneiss
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What environment produces the blueschist facies? Hints Basin Hot spot Mountain range Subduction zone Mid-ocean ridge
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Subduction zone
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Metamorphic index minerals are used by geologists to distinguish among different _____. Hints zones of subduction metamorphism zones of burial metamorphism zones of regional metamorphism zones of hydrothermal metamorphism zones of contact metamorphism
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zones of regional metamorphism
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What is a metamorphic facies? An assemblage of minerals that form in very similar metamorphic environments A rock that forms at specific metamorphic conditions and can be used to determine the metamorphic style Textural transitions based on the direction and amount of pressure Zones of contact metamorphism along an intrusive igneous rock
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An assemblage of minerals that form in very similar metamorphic environments
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What role does hot ion-rich water play in the process of metamorphism? Hints Water cleanses the iron-bearing minerals, which helps to delineate the crystal faces. Water boils the rocks that it comes in contact with, causing them to liquefy and slowly cool and harden into a new, stable state. Water migrates into host rock carrying ions to stable minerals in order to facilitate growth of new metamorphic minerals. Water interferes with mineral crystallization, thereby delaying the process of metamorphism. Water flows downhill, eroding the host rock to make it smooth.
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Water migrates into host rock carrying ions to stable minerals in order to facilitate growth of new metamorphic minerals.
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By what process did the gabbro turn into amphibolite? Hints The gabbro was heated to 500 ยฐC and buried a few miles below the Earth's surface. Gabbro naturally turns to amphibolite through the process of weathering over long periods of time. Explosive volcanic forces caused the gabbro to melt and the minerals in it to realign. Mineral-rich fluids from the overlying Paleozoic sedimentary rocks cemented the minerals in the gabbro and altered their structure. Mineral-laden water from the ocean caused changes in the mineral composition during the Grenville Orogeny.
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The gabbro was heated to 500 ยฐC and buried a few miles below the Earth's surface.
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What is a mantle plume? Hints a plume of fire a plume of hot water and gas that mobilizes the ions in the surrounding country rock a region of the mantle that has doubled in thickness hot mantle rock rising from deep within the Earth
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hot mantle rock rising from deep within the Earth
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What kind of metamorphic texture results in the segregation of light and dark mineral bands? Hints fine texture slaty texture foliated texture schistose texture gneissic texture
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gneissic texture
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Why are garnets used in sandpaper? Hints The sandpaper takes on an appealing reddish color when the garnets are incorporated into it. Garnets have many crystal faces and therefore have sharp edges. Garnets fracture easily and have abrasive edges. Garnets have a value of 8 or 9 on the Mohs Hardness Scale, making them very abrasive. Garnets have no other use.
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Garnets have a value of 8 or 9 on the Mohs Hardness Scale, making them very abrasive.