Geology Quiz 7

Which of the following statements about metamorphic rocks and their characteristic environments is true? Choose one: A. Slate, phyllite, schist, and gneiss are found in areas of continental collision. B. Hornfels is a result of burial metamorphism. C. Blueschists are found in the mid-ocean ridge. D. Foliated metamorphic rocks are usually found in contact aureoles surrounding plutons.

A. Slate, phyllite, schist, and gneiss are found in areas of continental collision.

Recrystallization Choose one: A. changes the texture (shape and size) of the grains. B. occurs when rocks undergo squeezing and grains change shape. C. occurs when chemical reactions digest minerals of the protolith and new minerals grow. D. changes the mineralogical composition of the protolith.

A. changes the texture (shape and size) of the grains.

A metamorphic rock Choose one: A. may have preferred mineral orientation caused by differential stress. B. is always composed of the same minerals as its protolith. C. cannot be formed below 1,200°C. D. cannot develop a texture of interlocking grains.

A. may have preferred mineral orientation caused by differential stress

What is the name of the type of foliation that is defined by the preferred orientation of large mica flakes, as shown in the photo (looking down on the foliation plane)? Choose one: A. schistosity B. phyllitic luster C. slaty cleavage D. gneissic banding

A. schistosity

Which of the following locations could possible be part of a shield? Choose one: A. Iceland B. Canada C. Japan D. Hawaii

B. Canada

On the graph shown, what do the numbered, dashed lines indicate? Choose one: A. geothermal gradients associated with different tectonic settings B. All of the possible answers are correct. C. the metamorphic facies a rock will pass through if it is buried in different tectonic settings D. how temperature changes with depth in different tectonic settings

B. all of the possible answers are correct

What type of foliation does slate, a common material used for roof shingles, exhibit? Choose one: A. metamorphic differentiation B. cleavage C. banding D. schistosity

B. cleavage

Shields are Choose one: A. composed of rocks that were metamorphosed during recent (less than a million years ago) mountain-building events. B. composed of some of the oldest rock on the Earth. C. rarely exposed at the Earth's surface and contain blueschist. D. composed of extensive areas of sedimentary layers laid down on lava flows.

B. composed of some of the oldest rock on the Earth

Which of the following rocks is nonfoliated ? Choose one: A. schist B. hornfels C. phyllite D. slate

B. hornfels

Mylonite, such as the example shown here, Choose one: A. is a product of gneiss melting to produce felsic magma and solid mafic rock. B. is produced by shear stress on softened rock. C. forms by fracturing brittle rock. D. has a pronounced foliation that is perpendicular to the direction of stress.

B. is produced by shear stress on softened rock.

The rocks on this map that underwent the deepest burial are now exposed at the surface in which state? Choose one: A. Maine B. Massachusetts C. New York D. Rhode Island

B. massachusetts

Which of the following is a common process during metamorphism? Choose one: A. lithification B. pressure solution C. brittle deformation D. melting

B. pressure solution

Hydrothermal fluids Choose one: A. are chemically active solutions that can dissolve and transport ions. B. can change a rock's chemical composition in a process known as metasomatism. C. All of the possible answers are correct. D. consist of hot water, steam, and supercritical fluid.

C. all of the possible answers are correct

Subduction zone metamorphism Choose one: A. All of the possible answers are correct. B. involves high temperatures and low pressure. C. forms the metamorphic rock blueschist. D. is similar to contact metamorphism.

C. forms the metamorphic rock blueschist

What is most likely true of a metamorphic rock that exhibits significant compositional banding, such as the one shown here? Choose one: A. It is formed under conditions of high temperature but low pressure. B. All of the possible answers are correct. C. It is a foliated rock called gneiss. D. It is formed by contact metamorphism.

C. it is a foliated rock called gneiss

Shear stress Choose one: A. is the reason a balloon shrinks when you take it to the bottom of a pool. B. is a compression exerted equally on all sides. C. moves material parallel to a surface. D. is a push (compression) or pull (tension) perpendicular to a surface.

C. moves material parellel to a surface.

Quartzite Choose one: A. breaks around the separate grains of quartz that compose it. B. always shows strong compositional banding. C. is always either white or gray. D. is basically a solid mass of interlocking quartz grains.

D. is basically a solid mass of interlocking quartz grains

What is the protolith of marble ? Choose one: A. quartz sandstone B. granite C. gypsum D. limestone

D. limestone

Identify the list of rock types that is ordered by increasing degrees of metamorphism (i.e., from lower to higher grade). Choose one: A. shale, migmatite, schist, phyllite B. schist, slate, phyllite, migmatite C. gneiss, phyllite, schist, slate D. slate, phyllite, schist, gneiss

D. slate, phyllite, schist, gneiss

In this image of a metamorphic rock viewed through a petrographic microscope, the preferred orientation of the mineral grains is ________, indicating that the direction of greatest compression was oriented ________. Choose one: A. horizontal; vertically B. There is no preferred orientation. C. The grains are too inequant to have a preferred orientation. D. vertical; horizontally

D. vertical; horizontally