GEO01 Reviewer 2

Which factor does NOT influence the viscosity of lava?

• Silica content

• Temperature

• Dissolved gases

• Plate tectonic setting

In order of decreasing size (largest listed first), sedimentary grain sizes include __.

• clay, sand, silt, and gravel

• gravel,  sand, silt, and clay

• gravel, sand, clay, and silt

• gravel, silt, sand, and clay

Partial melting of a rock will create a magma that is ______ than the composition of the original rock.

• less viscous

• more felsic

• darker in color

• more mafic

Magma that is very viscous can be associated with the most violent eruptions because they are ______________.

• Older

• rich in silica

• rich in water

• rich in carbon dioxide

Which of the following refers to the change or evolution of magma composition due to melting of surrounding country rock?

• Assimilation

• Crystal settling

• Magma mixing

• Partial melting

Which of the following gases is NOT typically released during a volcanic eruption?

• Oxygen

• Water vapor

• Sulfur dioxide

• Carbon dioxide

Complete the statement: "Fine-grained rocks (grains <1.0mm) that have small grains which cooled rapidly are likely to be ______________ rocks."

• obtrusive

• extrusive

• reclusive

• intrusive

Igneous rocks like gabbro and basalt are silica-deficient with high magnesium and iron. At which category will they be under?

• Felsic

• Intermediate

• Mafic

• Extrusive

Imagine two magmas that are identical in all respects (for example, same chemistry, pressure, volume) except that one magma is hotter than the other. Which magma will have the higher viscosity?

•  The hotter magma will be more viscous.

•  The cooler magma will be more viscous.

• Temperature does not affect magma viscosity.

• The magmas will have the same viscosity.

Which of the following refers to the two categories of igneous rocks based on where they solidified?

• intrusive and volcanic

• intrusive and extrusive

• volcanic and extrusive

• volcanic and plutonic