Practice Questions for Lecture 7
Geology 1200
Use these questions to test your knowledge of Lecture 7. The exams will be
similar in format, except that they will deal with more than one chapter, and
will have more questions total.
A. Short answer:
1. _____________ metamorphism develops from increased heat and
pressure in an area of plate convergence
2.___________ metamorphism takes place where rocks are heated by close
contact with magma.
3. __________ in gneisses is marked by the formation of distinct, single
mineral bands of alternating felsic and mafic minerals.
4. _________ metamorphism occurs when rocks are overlain by more than
10 km of rocks or sediments.
5. Minerals stable in a narrow range of temperatures and pressures are called
________ minerals.
6. _____________ plate interactions form most dynamothermal
metamorphism, and thus most foliated rocks.
7. Quartzite is formed by metamorphism of relatively pure quartz
______________, a type of sedimentary rock.
8. When temperatures increase to the melting points of felsic minerals, they
produce the part igneous, part metamorphic rock called _________.
9. Metamorphic facies can be used to determine the __________ and
pressure conditions that existed in the vicinity of a subduction zone.
10. The _________ required for metamorphism is more than 1 kilobar; this
occurs beginning at 3 kilometers beneath the Earth's surface.
B. Match the terms (Abbreviations: T temperature, P pressure, M
metamorphism
1. Migmatite _____
a. schist
2. Fractures in quartz grains______
b. M altered limestone
3. Marble ____
c. is stable in narrow range TP
4. New England____
d. gneiss
5. Banded metamorphic rock ____
e. quartzite
6. Index mineral _____
f. dynamothermal metamorphism
7. Visible, foliated Mica_____
g. hydrothermal M at mid-ocean ridge.
8. Low T, high P facies ___
h. contact metamorphism
9. Serpentine ______
i. shallow part subduction zone
10. Hornfels _____
j. partially melted
C. True or False?
1. In metamorphism, heat melts the minerals. True or False?
2. Lithostatic pressure pushes in on rocks equally from all sides, while
directed pressure acts in one principal plane. True or False?
3. Foliation refers to a consistent orientation of the mineral grains
perpendicular to the direction of greatest pressure. True or False?
4. Water facilitates metamorphic reactions by allowing movement of
atoms and ions. True or False?
5. The ultimate composition of a metamorphic rock is determined by
the temperature. True or False?
6. The metamorphism that results entirely from the heat of hot
circulating fluids is called contact metamorphism. True or False?
7. Contact metamorphism results from the directed pressure that exists
at the region of contact between two converging plates. True or False?
8. During contact metamorphism, pressure effects are extreme. True
or False?
9. New England was profoundly altered by regional metamorphism.
True or False?
10. One criterion used to classify metamorphic rocks is whether it is
foliated or nonfoliated. True or False?
D. Multiple choice:
1. Burial metamorphism involves processes of:
(a) heat and circulating fluids.
(b) heat and directed pressure.
(c) heat and confining pressure.
2. The type of metamorphism that occurs when rocks are caught between
two converging plates during mountain building is:
(a) contact metamorphism.
(b) shock metamorphism.
(c) burial metamorphism.
(d) dynamothermal metamorphism.
3. Mica schist can be distinguished from other metamorphic rocks by:
(a) its large parallel flakes of mica.
(b) its dark and light mineral bands.
(c) its metallic sheen.
(d) its slaty cleavage.
4. Gneiss can be distinguished from other metamorphic rocks by:
(a) its large parallel flakes of mica.
(b) its dark and light mineral bands.
(c) its metallic sheen.
(d) its slaty cleavage.
5. Which series shows the progression of a metamorphic rock from original
deposition to the highest grade of metamorphism?
(a) Mud  gneiss  migmatite  schist  phyllite  slate  shale.
(b) Mud  slate  schist  phyllite  migmatite  shale  gneiss.
(c) Mud  shale  slate  phyllite  schist  gneiss  migmatite.
(d) Mud  schist  phyllite  gneiss  slate  shale  migmatite.
6. A rock that has partially melted and is thus part igneous and part
metamorphic is a:
(a) phyllite.
(b) gneiss.
(c) migmatite.
(d) schist.
7. The rock that results from the metamorphism of limestone is called:
(a) hornfels.
(b) quartzite.
(c) gneiss.
(d) marble.
8. Metamorphism of quartz sandstone produces:
(a) hornfels.
(b) quartzite.
(c) gneiss.
(d) marble.
9. Which one of the following rock types would allow analysis of
metamorphic index minerals for pressure and temperature of formation?
(a) Schist.
(b) Limestone.
(c) Quartzite.
(d) Granite.
10. Metamorphic rocks beneath the mid-ocean ridge show evidence of: p126
(a) hydrothermal metamorphism.
(b) directed pressure similar to that of fault-zone metamorphism.
(c) lithostatic pressure similar to that of burial metamorphism.
(d) regional metamorphism along the entire length of the mid-ocean
ridge.
E. Short answer
1.
Which index mineral indicates the highest temperature of
formation in a metamorphic rock? Choose one: Chlorite /
Sillimanite / Biotite.
2.
Which Al2SiO5 polymorph indicates the highest pressure of
formation in a metamorphic rock if index minerals indicate the
temperature was about 400o Celsius? Choose one: Kyanite /
Sillimanite / Andalucite.