GEOL 3233 Lecture Notes - Lecture 7: Depositional Environment, Sphericity, Diamictite
11 Oct 2017
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(cid:862)float (cid:373)appi(cid:374)g(cid:863)-use regolith to identify underlying rocks (nice outcrops for mapping are not always present) If the type of ancient soil (paleosol) can be identified in the rock record then it can used to deduct info about paleoclimate since climate exerts a strong control on soil type. Two major types of weathering: mechanical (physical) Not as important as chemical except at subarctic or high elevations. Frost wedging: as h2o freezes, it expands, increasing pressures on the surrounding rock and creating fractures. Animals-worms turn over 10 tons of sediment per acre per year. Fiddler crabs-do a lot of burrowing on sand on barrier island: chemical weathering. Rate of chemical weathering is controlled by surface area. As mechanical weathering breaks up a rock, the surface area(and chemical weathering) increases exponentially. How fast minerals weather is determined by their stability. A list of minerals that crystallize from magma but it is also a weather ability series.
