Earth Sciences 1089F/G Lecture Notes - Lecture 19: Travertine, Stalactite, Cross-Bedding
7 Oct 2016
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Document Summary
Odd earth objects: unusual sights and sounds of earth. In the middle of the night in 1986, 1,700 people and thousands of animals does mysteriously in their sleep one night. After the disaster, it was noted that lake nyos developed a strange orange colour. Lake nyos occupies a crater of a dormant volcano, but the volcano has been inactive for 400 years disaster was not accompanied by any lava or debris. A natural topographic feature, rock outcrop, rock specimen, mineral specimen, etc. Many minetoliths are concretions bodies of cemented sediment. Commonly formed in marine sediment with abundant organic matter. In the process of eating the organic matter, certain bacteria release bicarbonate into the pores of the sediment. Bicarbonate combines with dissolved calcium in the porewater, to form crystals of calcite, which cement grains together. This cementation is often localized around a nucleus, such as a fossil.
