Test Bank For Physical Geology 14th Edition by Plummer

Test Bank For Physical Geology 14th Edition by Plummer

Chapter 03

Igneous Rocks, Intrusive Activity, and the Origin of Igneous Rocks

  True / False Questions

1. Rhyolite is considerably more common than granite.
FALSE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

2. Diorite and andesite are composed of similar amounts of feldspars and ferromagnesian minerals.
TRUE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

3. Lava is magma on the Earth’s surface.
TRUE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

4. Extrusive igneous rocks are typically fine grained because they crystallized slowly, deep below the Earth’s surface.
FALSE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

5. A dike is a discordant intrusive igneous structure.
TRUE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

6. The geothermal gradient is the rate at which pressure increases with increasing depth beneath the surface.
FALSE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

7. Mafic igneous rocks are silica-poor.
TRUE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

8. A mineral’s melting point generally increases with increasing pressure.
TRUE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

9. Although batholiths may contain mafic and intermediate rocks, they almost never composed of granite.
FALSE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

10. The sequence in which minerals crystallize in a cooling igneous melt is called Bowen’s Reaction Series.
TRUE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

11. The continuous branch in Bowen’s Reaction Series contains the ferromagnesian minerals.
FALSE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

12. A pluton is an igneous structure that crystallized at very shallow depths.
FALSE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

13. Partial melting of the lower continental crust produces a silicic magma that eventually solidifies into granite or rhyolite.
TRUE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

14. An ultramafic rock is composed almost entirely of quartz.
FALSE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

15. The term mafic comes from the terms magnesium and ferric.
TRUE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

16. The geothermal gradient for a volcanic region is greater than that for the continental interior.
TRUE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

17. The melting point of a rock decreases with increasing pressure.
FALSE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

18. Igneous rock names are based on grain shape and chemical composition.
FALSE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

19. Pegmatites are extremely coarse-grained igneous rocks.
TRUE

Bloom’s Level: 1. Remember
Topic: Igneous Environments

20. Basaltic magmas crystallize at higher temperatures than granitic magmas.
TRUE

Bloom’s Level: 2. Understand
Topic: Igneous Environments

Multiple Choice Questions

21. Igneous rocks may be either ____ if they form on or near Earth’s surface, or ___ if they solidify under ground.
A. intrusive; volcanic
B. volcanic; extrusive
C. extrusive; intrusive
D. plutonic; intrusive
E. intrusive; extrusive

Bloom’s Level: 1. Remember
Topic: Igneous Environments

22. A useful tool illustrating the relationships among igneous, sedimentary, and metamorphic rocks is called the ___.
A. weathering and erosion of surface features
B. plate tectonic cycle
C. relationships between preexisting rock
D. rock cycle
E. Bowen’s reaction series

Bloom’s Level: 2. Understand
Topic: Igneous Environments

23. ______ are fragments of country rock that are distinct from the body of igneous rocks in which they are enclosed.
A. Clasts
B. Chill zones
C. Phenocrysts
D. Xenoliths
E. Necks

Bloom’s Level: 1. Remember
Topic: Igneous Environments

24. Under ideal conditions rock can melt and yield a granite composition at temperatures as low as ___.
A. 100 Celsius
B. 225 Celsius
C. 333 Celsius
D. 450 Celsius
E. 650 Celsius

Bloom’s Level: 3. Apply
Topic: Igneous Environments

25. ______ igneous rocks, like gabbro and basalt, are silica-deficient with high magnesium and iron.
A. Felsic/silicic
B. Intermediate
C. Mafic
D. Intrusive
E. Extrusive