Quiz 9- Ch. 5

Question 1

volcano

Answer 1

consists of a magma chamber to which magma is transported from deep within earth, a plumbing system that transfers magma to the surface, one or more vents at the surface, and a hill or mountain constructed from lava/pyroclasts

Question 2

obsidian

Answer 2

a dense, glassy volcanic rock of felsic composition

Question 3

pumice

Answer 3

volcanic rock of rhyolitic composition that has numerous vesicles (cavities) that remain after trapped gas escapes from a solidifying lava

Question 4

volcanic ash

Answer 4

form of pyroclast that are fine fragments less than 2mm in diameter, usually of glass, that form when escaping gases force a fine spray of magma from a volcano

Question 5

volcanic bombs

Answer 5

pyroclast that is much larger and forms when blobs of lava are ejected from a volcano and cool in flight and become rounded or as chunks torn loose from already volcanic rock

Question 6

Tuffs

Breccias

Answer 6

pyroclasts that fall back to earth and weld together. the smaller fragments are called tuffs; the larger ones are called breccias

Question 7

pyroclastic flows

Answer 7

occur when hot ash, dust and gases are ejected in a glowing cloud and roll downhill at high speeds