GEO 303 Chapter Notes - Chapter 4: Halide Minerals, Sulfide Minerals, Silicate Minerals
10 May 2016
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Document Summary
The entire earth has been present for the past 4. 55 billion years, except meteorites. Because of recycling, highly unlikely we"ll find a preserved rock from the formation of the earth. No fixed schedule for recycling, some are old, some are new. Recycling requires the expenditure of energy, mostly earth"s internal energy. Sunlight, and energy from gravity are also important. Earths heat energy drives the motions of tectonic plates causing continents to drift, mountain belts to be uplifted, etc. Definition of rock: a rock is any coherent naturally occurring substance, generally composed of minerals. Definition of mineral: in order for a substance to be a mineral, it must satisfy four criteria. Minerals with carbon are in a gray area. Each species contains specific elements in definite proportions. The composed atoms are arranged in an orderly network at specific distances and angles to one another. Physical properties: each mineral has a discrete chemistry, and can be identified by chemical testing.
