1. Select the choice below that best describes the role of volatiles in an ascending magma.
-Volatiles increase the rate of crystallization in intrusive structures
-Volatiles will force the magma to contract as it rises
-Volatiles will shatter surrounding rocks, making it easier for the magma to rise
-Volatiles will expand with decreasing pressure, carrying the melt upward
2. The partial melting of a mafic magma would produce what composition of igneous rocks?
-Ultramafic
-Mafic
-Intermediate
-Felsic
3. What creates the small holes found in a vesicular texture?
-Liquid water
-Volatiles
-Soluble minerals
-Weathering
4. What is the geological definition of texture?
-How the sample feels to the touch
-The mineral content of the sample
-The percentage of silica in a sample
-Size and shape of mineral grains in the sample
5. What is the name of the pre-existing rock that is displaced by intrusive igneous bodies?
-Acid Rock
-Parent Rock
-Stock
-Country Rock
6. What is the term used to describe increased temperature with depth in the Earth?
-Decompression melting
-Convection cells
-Geothermal gradient
-Hydrothermal alteration
7. What magma would have formed from the partial melting of mantle material?
-Felsic Magma
-Primary Magma