GEOG 1290 Lecture Notes - Lecture 25: Lithification, Gneiss
29 Nov 2014
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Document Summary
Generally don"t show individual mineral crystals, but can if the crystals are. Form on earth"s surface, cooling rapidly formed from shattered rock that was explosively ejected. Basalt most common (extensive seafloor bedrock) a lot of earth"s crust. Sediments: component of fragments of preexisting rocks, known as detrital rocks, shale is an example, conglomerate: composed of pebble-sized rounded fragments. Chemical and organic sedimentary rocks: formed by precipitation of soluble materials or complicated chemical reactions, limestone and coal are examples, organize sedimentary rocks such as coal form from remains of dead plants and animals. Rocks altered in physical/chemical composition by heat, pressure and other processes taking place at a substantial depth below the surface. Rock fragments created by chemical and mechanical processes. Deposition usually occurs in a water body. Most deposits are built up in horizontal layers (strata) and result is stratification (parallel structure with varying layers) Weathering: breaking up of rocks into smaller pieces.
