Review Concepts on Deformation and Metamorphism

1. Review Concepts on Deformation and Metamorphism

2. 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.

3. 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.

4. 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.

5. 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.

6. Faults • Faults are classified by: A. Map pattern B. Stress field C. Age D. Dip and relative motion

7. Faults • Faults are classified by: A. Map pattern B. Stress field C. Age D. Dip and relative motion

8. Faults A normal Fault is characterized by A. Tensional Stress B. Steep Dip (>45o) C. Hanging wall down relative to footwall D. All of the above

9. Faults A normal Fault is characterized by A. Tensional Stress B. Steep Dip (>45o) C. Hanging wall down relative to footwall D. All of the above

10. Regional high-pressure metamorphism Regional metamorphism Shock metamorphism Contact metamorphism Regional metamorphism Depth, km Oceanic crust 0 35 Continental crust Oceanic lithosphere 75 Continental mantle lithosphere Asthenosphere Water Seafloor metamorphism Burial metamorphism

11. 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 Metamorphism B. Contact metamorphism C. Burial Metamorphism D. Subduction-zone metamorphism

12. 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 Metamorphism B. Contact metamorphism C. Burial Metamorphism D. Subduction-zone metamorphism

13. The lithosphere and asthenosphere interact to metamorphose rock High-pressure regional metamorphism is most closely associated with which tectonic environment? A. Continental rifting B. Mid-ocean ridge C. Subduction zone D. Meteorite impact

14. The lithosphere and asthenosphere interact to metamorphose rock High-pressure regional metamorphism is most closely associated with which tectonic environment? A. Continental rifting B. Mid-ocean ridge C. Subduction zone D. Meteorite impact

15. The lithosphere and asthenosphere interact to metamorphose rock Seafloor metamorphism that occurs at mid-ocean ridges is caused by: A. Directed pressure B. Confining pressure C. Metasomatism D. All of the above

16. The lithosphere and asthenosphere interact to metamorphose rock Seafloor metamorphism that occurs at mid-ocean ridges is caused by: A. Directed pressure B. Confining pressure C. Metasomatism D. All of the above

17. Increasing intensity of metamorphism Low grade Intermediate grade High grade Increasing crystal size Increasing coarseness of foliation

18. Diagenesis Low grade High grade Intermediate grade Slate Phyllite Migmatite Schist (abundant micaceous minerals) Gneiss (fewer micaceous minerals) Slaty cleavage Schistosity Banding Banding

19. Index minerals define metamorphic zones. Isograds can be used to plot the degree of metamorphism. Canada ME NY Isograds VT NH Key: MA Not metamorphosed CT Chlorite zone Low grade RI Biotite zone Garnet zone Medium grade Staurolite zone Sillimanite zone High grade

20. Degree of metamorphism Diagenesis Low Intermediate High Greenschists Amphibolites Granulites Chlorite White mica (mainly muscovite) Biotite Garnet Staurolite Kyanite Sillimanite Albite (sodium plagioclase) With increasing metamorphic grade, mineral composition changes. Mineral suites define metamorphic facies.

21. 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.

22. 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.

23. 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, schist B. Slate, phyllite, schist, gneiss C. Gneiss, schist, slate, phyllite D. Gneiss, phyllite, schist, slate

24. 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, schist B. Slate, phyllite, schist, gneiss C. Gneiss, schist, slate, phyllite D. Gneiss, phyllite, schist, slate

25. Texture, index minerals, grade, and facies describe metamorphism Metamorphic facies are defined by: A. Suites of minerals B. Foliation textures C. Pressures and temperatures D. Tectonic environments

26. Texture, index minerals, grade, and facies describe metamorphism Metamorphic facies are defined by: A. Suites of minerals B. Foliation textures C. Pressures and temperatures D. Tectonic environments