GEOL-101 Exam 2 Questions

What percentage of the crust of the earth is comprised of igneous and metamorphosed igneous rock?

• 100%, the crust is entirely igneous and metamorphosed igneous rock

• Around 85%

• About 50%

• None of the above.

Which is typically coarse grained?

• Granite

• Basalt

• Peridotite

• Granite and Basalt

• Granite and peridotite

Which class of igneous rock contains a relatively large amount of iron and magnesium?

• Felsic

• Banded iron formations

• Mafic

• Magnetite

What is the main causes for igneous melt generation below mid-ocean ridges?

• Decrease in temperature

• Decrease in pressure

• Decrease in water content

• All of the above

In the figure to the right showing ocean crust structure, which unit(A, B, C, D, E) is a gabbro?

• A

• B

• C

• D

• E

In terms of the origin of clastic sediment, identify the processes of mechanical weathering

• Thermal cycling and freezing water

• fracture from exhumation

• Root wedging

• A & B

• A, B, & C

Which class of sedimentary rocks is the most abundant in the Earth?

• Biological

• Clastic

• Chemical

In the figure to the right, which of the two sediments is most poorly sorted?

• A

• B

Identify the depositional environment with the following characteristics: Arid to humid; sand, mud, and gravel; river currents; some organic material

• Alluvial

• Lakes

• Delta

• Beach

• Tidal Flats

The progression from low to high metamorphic grade is associated with:

• increasing temperature

• increasing pressure

• increasing depth in the crust

• A & B

• A & B & C