10.1. A magma's viscosity is directly related to its ____.
10.2. Which of the following factors helps determine whether a volcanic eruption will be explosive or relatively quiet?
-amount of dissolved gasses in the magma
-temperature of the magma
-composition of the magma
10.3. A lava flow with a surface of rough, jagged blocks and sharp, angular projections is called a(n) ____.
10.4. As the temperature of lava increases, ____.
its viscosity decreases
10.5. Which list places the magma types in order of decreasing viscosity (most viscous listed first)?
rhyolitic, andesitic, basaltic
10.6. Which of the following is NOT a factor affecting how explosively or quietly a volcano erupts?
size of the volcano's cone
10.7. Highly explosive volcanoes tend to have what type of magma?
magma with high silica, high viscosity, and higher gas content
10.8. A volcanic bomb is a ____.
piece of semi-molten rock ejected as glowing lava
10.9. The particles produced in volcanic eruptions are called ____.
10.10. Which of the following is NOT considered to be a pyroclastic material?
10.11. Large particles of hardened lava ejected from a volcano are called ____.
10.12. Which of the following is true about volcanic blocks and bombs?
Bombs often have a streamlined shape.
10.13. What is the most abundant gas associated with volcanic activity?
10.14. What type of volcano is built almost entirely from ejected lava fragments?
10.15. The broad, slightly dome-shaped volcanoes of Hawaii are ____.
10.16. A volcano that is fairly symmetrical and has both layers of lava and pyroclastic deposits is a ____.
composite cone volcano
10.17. What feature is labeled D in Figure 10-1?
10.18. What feature is labeled A in Figure 10-1?
10.19. What type of volcano is illustrated in Figure 10-1?
10.20. Which of the following plays a major part in determining the form of a volcano?
10.21. Which of the following is true about cinder cones?
They have very steep sides.
They are usually less than 300 meters high.
They often occur in groups.
10.22. The most explosive volcanic eruptions are associated with what type of volcano?
10.23. A caldera is a ____.
large depression in a volcano
10.24. Lava plateaus form when ____.
fluid basaltic lava flows out of fissures
10.25. The volcanic landform that is formed when the more resistant volcanic pipe remains after most of the cone has been eroded is called a ____.
10.26. Crater Lake in Oregon was produced when ____.
the summit of a volcano collapsed
10.27. Structures that form from the cooling and hardening of magma beneath Earth's surface are ____.
10.28. How are intrusive igneous bodies classified?
by their size
by their shape
by their relationship to the surrounding rock layers
10.29. The largest intrusive igneous body is called a ____.
10.30. What is true about all plutons?
They form below Earth's surface.
10.31. Which type of intrusive feature forms when magma is injected into fractures cutting across preexisting rock layers?
10.32. A lens-shaped intrusive igneous mass close to Earth's surface is called a ____.
10.33. Which of the following is true about batholiths?
They are intrusive igneous bodies.
They are larger than stocks.
They are associated with major mountain ranges.
10.34. Which of the following factors affects the melting point of rock?
composition of the material
pressure of the surrounding rock
10.35. Most shield volcanoes have grown from the ocean floor to form ____.
10.36. If the feature labeled F in Figure 10-2 was exposed to erosion and reached over 100 square kilometers in area, it would be classified as a ____.
10.37. What volcanic feature is illustrated at A in Figure 10-2?
continental volcanic arc
10.38. What type of plate boundary resulted in the volcanic activity illustrated in Figure 10-2?
oceanic-continental convergent plate boundary
10.39. Which type of landform develops at plate boundaries where one oceanic plate descends beneath another?
volcanic island arc
10.40. At divergent plate boundaries in the ocean, magma rises and melts because of ____.
a decrease in pressure