METAMORPHIC ROCKS

Question 1

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

Answer 1

Blueschist

Question 1

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

Answer 1

burial during continental collision.

Question 2

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

Answer 2

Dynamothermal or regional metamorphism

Question 3

Which type of foliation does gneiss have?

Answer 3

Compositional layering

Question 4

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

Answer 4

phase change.

Question 5

Which agent of metamorphism involves hot water moving ions?

Answer 5

Interaction with hydrothermal fluids

Question 6

Metamorphic grade is determined mainly by

Answer 6

temperature.

Question 7

Identify the metamorphic process that is shown in the image.

Answer 7

Recrystallization

Question 8

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

Answer 8

250 to 400

Question 9

Which nonfoliated metamorphic rock forms from the metamorphism of limestone?

Answer 9

Marble

Question 10

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

Answer 10

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

Question 11

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.

Answer 11

Mountain belt metamorphism

Question 12

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?

Answer 12

Thermal or contact metamorphism

Question 13

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?

Answer 13

Igneous → metamorphic → sedimentary

Question 14

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

Answer 14

elongate perpendicular to the direction of stress.

Question 15

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?

Answer 15

Shear stress

Question 16

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

Answer 16

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

Question 17

Which process brings metamorphic rocks to the surface over time?

Answer 17

Exhumation

Question 18

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

Answer 18

slate.

Question 19

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

Answer 19

Plastic deformation

Question 20

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

Answer 20

marble

Question 21

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

Answer 21

metamorphism

Question 22

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

Answer 22

gneiss

Question 23

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

Answer 23

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

Question 24

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

Answer 24

in and out of the image, pulling outward

Question 25

Thermal (contact) metamorphism occurs

Answer 25

in areas surrounding igneous intrusions.

Question 26

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

Answer 26

minerals

Question 27

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

Answer 27

slate, phyllite, schist, and gneiss

Question 28

Regional metamorphism

Answer 28

is another name for dynamothermal metamorphism.

Question 29

Which of the following is a common foliated metamorphic rock?

Answer 29

gneiss

Question 30

What is a primary difference between phyllite and schist?

Answer 30

Mica crystals within schist are larger than those within phyllite.

Question 31

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

Answer 31

metamorphism

Question 32

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

Answer 32

quartzite; marble

Question 33

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

Answer 33

dynamothermal

Question 34

Rocks subjected to __________ feel a squeezing motion.

Answer 34

compression

Question 35

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

Answer 35

shale

Question 36

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

Answer 36

aureole

Question 37

Foliated metamorphic rocks possess

Answer 37

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

Question 38

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

Answer 38

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

Question 39

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

Answer 39

foliation