Unformatted text preview: giving the rock a coarse texture. It takes longer for this magma to cool because below the earth’s surface, the temperatures are higher and it is harder for these temperatures and gases to escape. So cooling can take a few months or even a few years. When the volcano erupts, the magma spreads over vast distances and quickly starts to cool. The magma cooled above the surface is known as extrusive or volcanic igneous rock. With the cooler temperatures above the earth’s surface, it allows the magma to cool faster, sometimes creating glass and small crystals over time....
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This note was uploaded on 06/23/2010 for the course SCI SCI/245 taught by Professor Daniellejannusch during the Spring '10 term at University of Phoenix.
- Spring '10