METAMORPHIC ROCKS Flashcards

1
Q

Different temperature and pressure ranges create specific sets of metamorphic minerals that are called metamorphic facies. Using the graph, determine what facies a rock would be found in if it was buried 30 km deep and heated to a temperature of approximately 200 degrees

A

Blueschist

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1
Q

Shale, a sedimentary rock, can be subjected to high heat and pressure through

A

burial during continental collision.

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2
Q

What type of metamorphism would occur at a plate boundary where two continents are colliding?

A

Dynamothermal or regional metamorphism

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3
Q

Which type of foliation does gneiss have?

A

Compositional layering

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4
Q

During metamorphism, the process that changes the crystal structure of a mineral without changing its chemical composition is called

A

phase change.

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5
Q

Which agent of metamorphism involves hot water moving ions?

A

Interaction with hydrothermal fluids

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6
Q

Metamorphic grade is determined mainly by

A

temperature.

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7
Q

Identify the metamorphic process that is shown in the image.

A

Recrystallization

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8
Q

The temperature range for the formation of low-grade metamorphic rocks is __________ degrees C.

A

250 to 400

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9
Q

Which nonfoliated metamorphic rock forms from the metamorphism of limestone?

A

Marble

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10
Q

Which statement about the pathways of the rock cycle is TRUE?

A

Granite that is eroded, transported, deposited, and lithified will become a sedimentary rock.

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11
Q

Using the graph, determine what type of metamorphism (related to its geologic setting) a rock would likely be experiencing if it was at a depth of 20 km and heated to a temperature of 500 degrees C.

A

Mountain belt metamorphism

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12
Q

Metamorphism can occur in the surrounding rock as an igneous pluton forms. Which type of metamorphism is most likely to occur in the surrounding rock?

A

Thermal or contact metamorphism

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13
Q

A rock experienced melting then cooling, burial to deep depths during mountain building, and then uplift and weathering. Which pathway did this rock take through the rock cycle?

A

Igneous → metamorphic → sedimentary

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14
Q

When a rock is subjected to compressional pressure, the grains will

A

elongate perpendicular to the direction of stress.

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15
Q

In a rock undergoing metamorphosis, which type of stress occurs when one part of a rock moves sideways relative to the rest of the rock?

A

Shear stress

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16
Q

Which of the following describes an igneous to metamorphic to sedimentary path through the rock cycle?

A

A granite becomes buried and heated to form gneiss, and is then uplifted and eroded to make sand.

17
Q

Which process brings metamorphic rocks to the surface over time?

A

Exhumation

18
Q

The fine-grained foliated metamorphic rock formed from the metamorphism of shale or mudstone is called

A

slate.

19
Q

Identify the metamorphic process that causes grains to warp and/or elongate but not melt or dissolve.

A

Plastic deformation

20
Q

A nonfoliated metamorphic rock that is composed entirely of calcite is called

A

marble

21
Q

Clay minerals within a buried body of slate are recrystallized at high temperatures and pressures to form mica, producing a rock called phyllite. This is an example of

A

metamorphism

22
Q

Which of the following is a high-grade metamorphic rock?

A

gneiss

23
Q

In the formation of gneiss (from a granite protolith), distinctive compositional bands form because of

A

crystals dissolving, with atoms and ions migrating and reorganizing as new crystals.

24
Q

What was the direction of compression that formed the foliation in the image below?

A

in and out of the image, pulling outward

25
Q

Thermal (contact) metamorphism occurs

A

in areas surrounding igneous intrusions.

26
Q

Foliation may include the alignment of __________ in a metamorphic rock.

A

minerals

27
Q

Which list properly orders these foliated metamorphic rocks from lowest grade to highest grade?

A

slate, phyllite, schist, and gneiss

28
Q

Regional metamorphism

A

is another name for dynamothermal metamorphism.

29
Q

Which of the following is a common foliated metamorphic rock?

A

gneiss

30
Q

What is a primary difference between phyllite and schist?

A

Mica crystals within schist are larger than those within phyllite.

31
Q

A buried body of shale is subjected to differential stress, causing clay minerals to realign and produce slate. This is an example of

A

metamorphism

32
Q

Two common metamorphic rocks that typically lack foliation are __________ and __________.

A

quartzite; marble

33
Q

What type of metamorphism affects the greatest volumes of rock and produces the greatest variety in metamorphic rock types?

A

dynamothermal

34
Q

Rocks subjected to __________ feel a squeezing motion.

A

compression

35
Q

Which of the following is a common protolith involved in the formation of slate?

A

shale

36
Q

Consult the figure below. The region of thermally metamorphosed rock surrounding a cooled pluton is called a(n)

A

aureole

37
Q

Foliated metamorphic rocks possess

A

mineral grains in preferred orientations or patterns of association such as banding.

38
Q

Which of the following processes CANNOT occur in the formation of metamorphic rock?

A

complete melting of the rock, followed by solidification to form a new rock

39
Q

Slaty cleavage, schistosity, and compositional banding are all examples of

A

foliation