Volcanoes

2. hot fluid or semifluid material below or within the earth's crust from which lava and other igneous rock is formed on cooling.
4. a small area or region with a relatively hot temperature in comparison to its surroundings.
5. a curved chain of volcanic islands located at a tectonic plate margin, typically with a deep ocean trench on the convex side.
7. a body of intrusive igneous rock.
12. hot molten or semifluid rock erupted from a volcano or fissure, or solid rock resulting from cooling of this.
13. forms when magma remains inside the Earth's crust where it cools and solidifies in chambers within pre-existing rock.
15. when lava and gas are released from a volcano—sometimes explosively
16. a dark, coarse-grained plutonic rock of crystalline texture, consisting mainly of pyroxene, plagioclase feldspar, and often olivine.
18. a large, bowl-shaped cavity in the ground or on the surface of a planet or the moon, typically one caused by an explosion or the impact of a meteorite or other celestial body.
19. a small piece of partly burned coal or wood that has stopped giving off flames but still has combustible matter in it.
20. a localized column of hot magma rising by convection in the mantle, believed to cause volcanic activity in hot spots, such as the Hawaiian Islands, away from plate margins.

1. a dark gray to black dense to fine-grained igneous rock that consists of basic plagioclase, augite, and usually magnetite.
3. any steep-sided mound that is formed when lava reaching the Earth's surface is so viscous that it cannot flow away readily and accumulates around the vent
6. the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
8. large volcanoes (many thousands of feet or meters tall) generally composed of lava flows, pyroclastic deposits, and mudflow (lahar) deposits, as well as lava domes
9. a large volcanic crater, especially one formed by a major eruption leading to the collapse of the mouth of the volcano.
10. a very light and porous volcanic rock formed when a gas-rich froth of glassy lava solidifies rapidly.
11. the rigid outer part of the earth, consisting of the crust and upper mantle.
14. relating to or denoting a group of light-colored minerals including feldspar, feldspathoids, quartz, and muscovite.
17. lava fragments larger than 64 mm in diameter that were ejected while still viscous and partially molten