Earth Sciences 2240F/G Lecture Notes - Lecture 15: 2008 California Wildfires, Coesite, Deep Sea Drilling Project
20 Apr 2016
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1. 0 case study 1: meteor crater (barringer crater) We"ll start with the best-studied impact crater on earth. It has been known for a very long time that there was an enormous crater in the middle of the desert of arizona, not far from present-day flagstaff. First, it was said to be an explosive hole made by a gas-rich volcano, but no true volcanic rocks were ever found nearby. Then it was called the weathered-out top of a salt dome but there was no salt anywhere. Finally, in the late 1870s there were abundant rumors that chunks of silver had been found lying on the ground near. In 1891, a sample was sent to an assayer in denver with the message that there were "carloads" of the stuff lying around. The assayer was mildly incompetent, and reported back that the sample was largely iron, but contained 1. 8% lead, 0. 025% silver and trace gold.
