Post on 15-Jan-2016
Review Concepts on Deformation and Metamorphism
Which statement regarding synclines is true?
A. Limbs dip toward the axial plane where the oldest strata are exposed.B. Limbs dip toward the axial plane where the youngest strata are exposed.C. Limbs dip away from the axial plane where the oldest strata are exposed.D. Limbs dip away from the axial plane where the youngest strata are exposed.
Rock folding
Which statement regarding synclines is true?
A. Limbs dip toward the axial plane where the oldest strata are exposed.B. Limbs dip toward the axial plane where the youngest strata are exposed.C. Limbs dip away from the axial plane where the oldest strata are exposed.D. Limbs dip away from the axial plane where the youngest strata are exposed.
Rock folding
What characterizes a fold as being a plunging fold?
A. The limbs dip at different angles from one another.B. The limbs both dip in the same direction.C. The axial plane is not vertical.D. The fold axis is not horizontal.
Rock folding
What characterizes a fold as being a plunging fold?
A. The limbs dip at different angles from one another.B. The limbs both dip in the same direction.C. The axial plane is not vertical.D. The fold axis is not horizontal.
Rock folding
Faults
• Faults are classified by:A. Map patternB. Stress fieldC. AgeD. Dip and relative motion
Faults
• Faults are classified by:A. Map patternB. Stress fieldC. AgeD. Dip and relative motion
Faults
A normal Fault is characterized byA. Tensional StressB. Steep Dip (>45o)C. Hanging wall down relative to footwallD. All of the above
Faults
A normal Fault is characterized byA. Tensional StressB. Steep Dip (>45o)C. Hanging wall down relative to footwallD. All of the above
Depth,km
0
35
75
Asthenosphere
Continental crust
Continental crust
Regional metamorphism Oceanic
crust
Oceaniclithosphere
Shockmetamorphism
Regionalmetamorphism
Regionalhigh-pressuremetamorphism
Contactmetamorphism
Burialmetamorphism
Continental mantle lithosphere
Continental mantle lithosphere
Water
Seafloormetamorphism
Which kind of metamorphism is caused primarily by increasing temperature with little change in pressure?
A. Regional MetamorphismB. Contact metamorphismC. Burial MetamorphismD. Subduction-zone metamorphism
The lithosphere and asthenosphere interact to metamorphose rock
Which kind of metamorphism is caused primarily by increasing temperature with little change in pressure?
A. Regional MetamorphismB. Contact metamorphismC. Burial MetamorphismD. Subduction-zone metamorphism
The lithosphere and asthenosphere interact to metamorphose rock
High-pressure regional metamorphism is most closely associated with which tectonic environment?
A. Continental riftingB. Mid-ocean ridgeC. Subduction zoneD. Meteorite impact
The lithosphere and asthenosphere interact to metamorphose rock
High-pressure regional metamorphism is most closely associated with which tectonic environment?
A. Continental riftingB. Mid-ocean ridgeC. Subduction zoneD. Meteorite impact
The lithosphere and asthenosphere interact to metamorphose rock
Seafloor metamorphism that occurs at mid-ocean ridges is caused by:
A. Directed pressureB. Confining pressure C. MetasomatismD. All of the above
The lithosphere and asthenosphere interact to metamorphose rock
Seafloor metamorphism that occurs at mid-ocean ridges is caused by:
A. Directed pressureB. Confining pressure C. MetasomatismD. All of the above
The lithosphere and asthenosphere interact to metamorphose rock
Increasing intensity of metamorphism
Increasing crystal size
Increasing coarseness of foliation
Low grade Intermediate grade High grade
Slate Phyllite Schist(abundantmicaceousminerals)
Gneiss(fewer
micaceousminerals)
Migmatite
Slaty cleavage Schistosity Banding Banding
Diagenesis Low grade Intermediategrade
High grade
Canada
NY
VT
ME
NH
MA
CT
RI
Isograds
Key: Notmetamorphosed
Chlorite zone
Biotite zone
Garnet zone
Staurolite zone
Sillimanite zone
Lowgrade
Medium grade
High grade
Index minerals define metamorphic zones. Isograds can be
used to plot thedegree of metamorphism.
Degree of metamorphism
Diagenesis
Greenschists
Low Intermediate
Amphibolites Granulites
High
Chlorite
White mica (mainly muscovite)
Biotite
Garnet
Staurolite
Sillimanite
Kyanite
Albite (sodium plagioclase)
With increasing metamorphicgrade, mineral compositionchanges.
Mineral suites definemetamorphic facies.
How do crystal size and foliation change with increasing intensity of metamorphism?
A. Grain size increases and foliation becomes less coarse.B. Grain size decreases and foliation becomes coarser.C. Both grain size and foliation coarseness decrease.D. Both grain size and foliation coarseness increase.
Texture, index minerals, grade, and facies describe metamorphism
How do crystal size and foliation change with increasing intensity of metamorphism?
A. Grain size increases and foliation becomes less coarse.B. Grain size decreases and foliation becomes coarser.C. Both grain size and foliation coarseness decrease.D. Both grain size and foliation coarseness increase.
Texture, index minerals, grade, and facies describe metamorphism
Which list places foliation textures in order of increasing metamorphic grade (low grade to high grade)?
A. Slate, gneiss, phyllite, schistB. Slate, phyllite, schist, gneissC. Gneiss, schist, slate, phylliteD. Gneiss, phyllite, schist, slate
Texture, index minerals, grade, and facies describe metamorphism
Which list places foliation textures in order of increasing metamorphic grade (low grade to high grade)?
A. Slate, gneiss, phyllite, schistB. Slate, phyllite, schist, gneissC. Gneiss, schist, slate, phylliteD. Gneiss, phyllite, schist, slate
Texture, index minerals, grade, and facies describe metamorphism
Metamorphic facies are defined by:
A. Suites of mineralsB. Foliation texturesC. Pressures and temperaturesD. Tectonic environments
Texture, index minerals, grade, and facies describe metamorphism
Metamorphic facies are defined by:
A. Suites of mineralsB. Foliation texturesC. Pressures and temperaturesD. Tectonic environments
Texture, index minerals, grade, and facies describe metamorphism