Which one of the following factors is most important in determining the texture of an igneous rock?
A. the type of dissolved gases in the magma
B. the rate at which the magma cools
C. the composition of the magma
D. the type of rock surrounding the magma
E. the time of the year the rock forms
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What is meant by “extrusive” and “intrusive”?
A. Igneous rocks that cooled at the surface (volcanic) and interior to the surface (plutonic) of the Earth, respectively.
B. Sedimentary rocks that cooled at the surface (volcanic) and interior to the surface (plutonic) of the Earth, respectively.
C. Metamorphic rocks that cooled at the surface (volcanic) and interior to the surface (plutonic) of the Earth, respectively.
D. All of these.
In the field, when you tried to identify the hardness of an unknown mineral, you found that it scratches your fingernail, but not the copper coin. In fact, the copper coin scratres the mineral. Then what would be the range in hardeness for this mineral?
A. greater than 3 but less than 7
B. greater than 1 but less than 3
C. greater than 5
D. greater than 5 but less than 7
E. greater than 3 but less than 5
F. less than 1
Which of the following is not true about the two minerals graphite and diamond?
A. same chemistry but different crystal structures
B. diamond is “harder”
C. same crystal structure but different chemistry
D. both are composed of carbon atoms
The best approximation of the true outer boundary of the continents is the seaward edge of the ____________.
A. abyssal plain
B. continental shelf
C. mid-ocean ridge
D. present-day shorelines
E. deep-ocean trench
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