GEOG 111 Lecture Notes - Lecture 7: Cascadia Subduction Zone, Silicate Minerals, Subduction
6 Apr 2016
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Lecture 7: earth crust dynamic and the rock cycle. Rocks are naturally occurring solid assemblage of minerals. ~3000 minerals (20 common minerals, 10 make up 90% of the earth"s crust. Silicate minerals: contains silicon (si) and oxygen (o) Alumino- silicate minerals: rice in aluminum (al) with little iron (fe) and magnesium (mg, felsic. Ferro- magnesian mineral: rich in magnesium (mg) and iron (fe, mafic. Assemble or aggregate of minerals in solid state. Components (minerals) can be separated by physical means. Classification based on: manner of formation, environment of formation. Formed by cooling and solidification of molten rock: magma: molten rock in earth"s interior, lava: molten rock on earth"s surface. Classification: based on compost ion of molten rock. Mafic, felsic or intermediate: based on rate of cooling. Extrusive igneous rock: cool on surface rapid cooling, small crystals. Intrusive igneous rocks: cool below surface slow cooling, large crystals. In water: extremely fast cooling no crystals (glass)
