GEOL 102 Lecture Notes - Lecture 8: Trace Fossil Classification, Pyrite, Permineralization
31 Oct 2017
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All the changes that occur b/w death and discover as a fossil. Ecology of fossils including all aspects of an organisms life and environment. Fossil: any object that provides evidence of prehistoric life e. g. shells and bones. Fossil lagerstatten - a place with an abundance of fossils. Shows the complete community of organisms e. g. burgess shales. Fossils 6 methods of creating a fossil: unaltered soft parts. No change to organic tissues besides the loss of water. Can happen 1 of 3 ways: freezing very rare. Can add or remove water e. g. aragonite goes to calcite silica goes to quartz (looses water) Inill of porous skeletons with minerals that precipitate out of fluids e. g. wood and dinosaur bones perimin. with silica corals and echinoderms perimin. with calcite: leached fossils. Heat and pressure drive off the volatiles from the skeletons. Leaves a thin film of carbon which is black (coal) or silvery (graphite)
