Deck 8: Metamorphism and Metamorphic Rocks

Question 1

The changes in texture and composition of metamorphic rocks result from the compaction and cementation of pre-existing rocks.

Answer 1

False

Question 2

Metamorphic rocks are generally older than sedimentary and igneous rocks.

Answer 2

False

Question 3

Metamorphism of a mudstone will produce slate, schist, gneiss, and hornfels.

Answer 3

True

Question 4

Heat that results in metamorphism is the result igneous intrusions and from deep burial.

Question 5

The relationship between heat and pressure is known as the geothermal gradient.

Question 6

Lithostatic pressure will cause a rock to be compressed equally in all directions.

Question 7

Although metamorphism involves changes occurring in the solid state, pore fluids play an important role in transporting ions in solution.

Question 8

Regional metamorphism is most common along divergent margins.

Question 9

The pressure involved in regional metamorphism is differential pressure.

Question 10

An isograd represents a line of equal metamorphic intensity or grade.

Question 11

The blueschist facies is associated with relatively low temperature and high pressure along subduction zones.

Question 12

The concept of metamorphic facies applies to any type of parent rock.

Question 13

Metamorphic rocks are those which

A) are claimed to have certain metaphysical properties,
B) have mineral compositions altered from those originally present by increased temperature and pressure.
C) have textures altered from those originally present by agents such as water and volatile magmatic fluids.
D) have chemical compositions altered from those originally present by agents such as organisms and tectonic plates.
E) B and C

Question 14

The word elements meta and morph are Latin for

A) hidden and shape.
B) hidden and rock.
C) change and rock.
D) change and shape.
E) hidden and body.

Question 15

Foliated metamorphic textures form under which of the following circumstances?

A) convergent plate margins
B) regional metamorphism
C) differential pressure
D) both B and C
E) all of the above

Question 16

Metamorphism of a mudstone will produce

A) slate
B) gneiss
C) hornfels
D) A and B
E) all of the above

Question 17

Contact metamorphism is found along the boundaries between country rock and

A) dikes.
B) batholiths.
C) laccoliths.
D) sills.
E) all of the above

Question 18

The zone of metamorphism between country rock and intrusive igneous rock is known as

A) the oriole.
B) the orio.
C) the aureole.
D) the arena.
E) the areal.

Question 19

Which of the following correctly lists metamorphic mineral assemblages in order of decreasing temperature/pressure of formation?

A) chlorite, biotite, garnet, staurolite, kyanite, sillimanite
B) biotite, garnet, chlorite, staurolite, sillimanite, kyanite
C) garnet, biotite, chlorite, sillimanite, staurolite, kyanite
D) sillimanite, staurolite, kyanite, garnet, biotite, chlorite
E) sillimanite, garnet, kyanite, staurolite, biotite, chlorite

Question 20

Which of the following rocks may be associated with contact metamorphism?

A) gneiss
B) slate
C) hornfels
D) B and C
E) none of the above

Question 21

Most metamorphic rocks are the result of

A) dynamic metamorphism.
B) hydrothermal alteration.
C) contact metamorphism.
D) regional metamorphism.
E) country rock baking.

Question 22

Kyanite, andalusite and sillimanite

A) are index minerals formed from clay-rich parent rocks.
B) form from the same parent rocks under different combinations of pressure and temperature.
C) can transform from one to the other depending on changes in temperature and pressure.
D) have the same chemical composition.
E) all of the above

Question 23

The type of pressure that results from the weight of overlying rocks and is equal in all directions is___________pressure.

Question 24

___________pressure is equal in all directions while___________ pressures are not equal on all sides.

Question 25

As an agent of metamorphism ___________ ___________ promotes metamorphism by increasing rates of chemical reactions/by carrying ions in solution?

Question 26

Asbestos can be broadly divided into the two mineral composition groups and___________ ___________?

Question 27

Many ore deposits, such as hematite, tungsten, or galena, are formed by___________ .

Question 28

A group of metamorphic rocks formed under the same broad conditions of temperature and pressure is termed a ___________ ___________.

Question 29

Migmatites are the result of ___________-grade metamorphism.

Question 30

What is the relation between the type of tectonic plate boundary and type of metamorphism?

Question 31

What are two different types of pressures to which rocks can be subjected and in what general environments would each be found?

Question 32

Is the concept of metamorphic facies applicable to all rock types? Explain

Question 33

What are some of the analytical techniques which geologists have employed to help determine the authenticity of historical marble artworks such as sculptures and artifacts?

Question 34

How can carbon and oxygen isotope analysis help in the authentication process of marble artworks?

Question 35

What is the most important fluid which can promote metamorphism?

Question 36

What are possible sources for heat sufficient to cause metamorphism?

Question 37

Which mineral group is the source of most commercial asbestos?

Question 38

Why is asbestos considered a health hazard?

Question 39

What are the three types of metamorphism which are recognized?

Question 40

What are index minerals, as the term is applied to metamorphic rocks?

Question 41

What causes contact metamorphism?

Question 42

What is the difference between foliation and exfoliation?

Question 43

Name five metamorphic rocks or minerals which have an economic use. After each, give a use for the rock or mineral.

Question 44

Is most of the world's commercial graphite production presently of natural or synthetic graphite?

Question 45

What are six of the many uses for graphite?