GEO 101 Lecture Notes - Lecture 19: Asarco, Phanerozoic, Pyrite
14 Nov 2016
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Document Summary
Sulfides combine with air and water to form acids. Pyrite (fes2) and other sulfides occur with coal and with many valuable metals which are mined. Waste rock and overburden are dug up, broken into pieces and left on the surface. Runoff from mining sites is acidic and contains toxic metals. Arizona near patagonia, after heavy rainfall, from asarco mines closed in 1940s, 1960s. Earth climate fluctuates in 100 million year cycles. Climate change on scales of millions of years can largely be attributed to tectonic causes: arrangement of continents can make earth colder. N-s configuration, blocking e-w oceanic circulation (check her page in the future for updated explanation of this point) More warm water, more evaporation, more snowfall: continents moving can make earth warmer. Increase in volcanism results in increase in greenhouse gases. Last million years: earth has been in a cold stage (temperatures below average, on time scale of millions of years), with glacial periods and warm interglacials.
