Geo Chap 8

Geo Chap 8 - January 31, 2008 & February 7, 2008...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 8: Page 1 Geological Catastrophes: Chapters Eight Chapter 8 Vocabulary: 1. AA : Lava flow with a rough, blocky surface. 2. Andesite : A volcanic rock named for the Andes Mountains in South America. It is intermediate in composition between basalt and rhyolite and commonly results from melting of continental rock in basaltic magma. 3. Basalt : A dark, finely crystalline volcanic rock typical of low-viscosity oceanic lavas. 4. Base Surge : A cloud of volcanic gas and suspended debris that flows rapidly over the ground. 5. Caldera : A large (over 2 km diameter), basin-shaped volcanic depression, roughly circular in map view, that forms by a pistonlike collapse of a cylinder of overlying rock into an underlying partially evacuated magma chamber. 6. Cinder Cone : Steep volcanic hill made of loose pyroclastic debris. 7. Composite Volcano : A volcano constructed of alternating layers of pyroclastic debris and lava flows. Also known as a stratovolcano. 8. Crater : An abrupt basin commonly rimmed by ejected material. In volcanoes, craters form by outward explosion, are commonly less than 2 km diameter, and occur at the summit of a volcanic cone. Similar rimmed basins form by impacts with meteorites, asteroids, and comets. 9. Crystallization : The growth of minerals in a fluid such as magma. 10. Decompression Melting : The most common process creating magma is by reducing pressure on hot rock, not by adding more heat. 11. Fissure : A narrow parting or crack in rock. 12. Flood Basalt : Tremendous outpourings of basaltic lava that form thick, extensive plateaus. 13. Geyser : A hot spring that gushes magma-heated water and steam. 14. Lahar : A volcanic mudflow composed of unconsolidated volcanic debris and water. 15. Lava Dome : A mountain or hill made from high viscous lava, which plugs the central conduit of volcanoes. 16. Mineral : A naturally formed, solid inorganic material with characteristic chemical composition and physical properties that reflect an internally ordered atomic structure. 17. Obsidian : Dark volcanic glass. 18. Pahoehoe : Lava flow with a smooth, ropy surface. 19.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 6

Geo Chap 8 - January 31, 2008 & February 7, 2008...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online