ESC 1000 Earth Science Name: ____________

Chapter 9: Volcanoes and Other Igneous Activity

Part K Chapter 9 Key Terms 40 Points

Fill in the blanks with the word or words that best fit the definition:

1. _______________– A type of lava flow that has a jagged blocky surface.

2. _______________– A large mass of igneous rock that formed when magma was emplaced at depth, crystallized, and subsequently exposed by erosion.

3. _______________ – A large depression typically caused by collapse or ejection of the summit area of a volcano.

4. _______________– A rather small volcano built primarily of pyroclastics ejected from a single vent.

5. _______________ – A pattern of cracks that form during cooling of molten rock to generate columns that are generally six-sided.

6. _______________ – A volcano composed of both lava flows and pyroclastic materials.

7. _______________ – A pipelike opening through which magma moves toward Earth’s surface. It terminates at a surface opening called a vent.

8. _______________– Mountains formed in part by igneous activity associated with the seduction of oceanic lithosphere beneath a continent.

9. _______________– The depression at the summit of a volcano, or that which is produced by a meteorite impact.

10. _______________– Melting that occurs as rock ascends due to a drop in confining pressure.

11. _______________ - A tabular –shaped intrusive igneous feature that is cuts through the surrounding rock.

12. _______________ – A crack in the crust which allows Volcano activity to frequently begin if magma can move forcefully toward the surface..

13. _______________– An eruption in which lava is extruded from narrow fractures or cracks in the crust.

14. _______________– Flows of basaltic lava that issue from numerous cracks or fissures and commonly cover extensive areas to thickness of thousands of meters.

15. _______________– A vent in a volcanic area from which fumes or gases escape.

16. _______________– The gradual increase in temperature with depth in the crust. The average is 30ºC per kilometer in the upper crust.

17. _______________– A concentration of heat in the mantle capable of producing magma, which in turn extrudes onto Earth’s surface. The intraplate volcanism that produced the Hawaiian Islands is one example.

18. _______________– Igneous activity that occurs within a tectonic plate away from boundaries.

19. _______________– See Volcanic island arc

20. _______________– A massive igneous body intruded between preexisting strata.

21. _______________– Mudflows on the slopes of volcanoes that result when unstable layers of ash and debris become saturated.

22. _______________– A mass of hotter than normal mantle material that ascends toward the surface, where it may lead to igneous activity. These plumes of solid yet mobile material may originate as deep as the core-mantle boundary.

23. _______________– Destructive fiery flows, capable of racing down steep volcanic slopes at speeds that can approach 200 kilometers (125) per hour.

24. _______________– A lava flow with a smooth-to-ropey surface.

25. _______________– A volcanic cone that forms on the flank of a larger volcano.

26. _______________ – The process by which most igneous rocks melt. Since individual minerals have different melting points, most igneous rocks melt over a temperature range of a few hundred degrees. If the liquid is squeezed out after some melting has occurred, a melt with a higher silica content results.

27. _______________ – A vertical conduit through which magmatic materials have passed.

28. _______________ – A structure that results from the emplacement and crystallization of magma beneath the surface of Earth.

29. _______________– A highly heated mixture, largely of ash and pumice fragments, traveling down the flanks of a volcano or along the surface of the ground.

30. _______________– The volcanic rock ejected during an eruption, including ash, bombs, and blocks.

31. _______________– See cinder cone

32. _______________– A broad, gently sloping volcano built from fluid basaltic lavas.

33. _______________– A tabular igneous body that was intruded parallel to the layering of preexisting rock.

34. _______________– See composite cone.

35. _______________ – surface opening

36. _______________– A measure of a fluid’s resistance to flow.

37. _______________– Gaseous components of magma dissolved in the melt. Volatiles will readily vaporize (form a gas) at surface pressures.

38. _______________– A chain of volcanic islands generally located a few hundred kilometers from a trench where active subduction of one oceanic slab beneath another is occurring. Same as island arc.

39. _______________– An isolated, steep-sided, erosional remnant consisting of lava that once occupied the vent of a volcano.

40. _______________ – A mountain formed of lava and/or pyroclastics.

Chapter 9: Volcanoes and Other Igneous Activity

AA flow	Furmarole	Pyroclastic Flow
Batholith	Geothermal Gradient	Pyroclastic Material
Caldera	Hot Spot	Scoria Cone
Cinder Cone	Intraplate Volcanism	Shield Volcano
Columnar Joint	Island Arc	Sill
Composite Cone	Laccolith	Strato volcanoes
Conduit	Lahar	Vent
Continental Volcanic Arc	Mantle Plume	Viscosity
Crater	Muee Ardente	Volatiles
Decompression Melting	Pahoehoe Flow	Volcanic Island Arc
Dike	Parasitic Cone	Volcanic Neck
Fissure	Partial Melting	Volcano
Fissure eruption	Pipe
Flood basalt	Pluton