GEOL 150Lg Lecture Notes - Lecture 14: Laterite, Chronicle, Evaporite
Document Summary
Permian was the last phase of the paleozoic. Early geologists found evidence of past glaciaions in u-shaped valleys. Fossils of tropical animals in london are evidence of a once warmer climate. Draw down co2 from the atmosphere: coal deposits: Removed at least 3,000 gt of carbon from the atmosphere. Formed during the icehouse phase of earth history: organic rich marine clays, chalk. Dimethyl sulide (cloud nuclei) is an aerosol produced by these organisms. Volcanic acivity: causes short term cooling due to aerosols, causes long-term warming if there is a sustained release of co2, currently low. Ancient desert sediments: idenify shiting posiion of major atmospheric cells, formed in dry and monsoon climates. Glacial sediments: idenify periods of glaciaion, clarify extent of glaciaion, contain rock fragments that indicate place where ice sheets originated. Evaporite deposits: idenify areas of intense evaporaion, occur mostly in subtropical arid zones. Caliche: fossil carbonate-enriched soil, forms where there is a high rate of evaporaion.
