EPS SCI 3 Study Guide - Quiz Guide: Polycyclic Aromatic Hydrocarbon, Pilbara Craton, Raman Spectroscopy
17 Nov 2016
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Document Summary
Fossil: preserved remains or traces of animals, plants and other organisms from the remote past >10,000 years ago and bones, teeth of vertebrates or the chitinous exoskeletons of intervertebrates are usually preserved (soft tissues are rarely preserved) Trace fossils (ichofossils): can also consist of the marks left behind while alive (footprints/feces-coprolites) of a reptile. Chemofossils/biomarkers: markers that past life leaves that cannot be seen but can be detected in the form of biochemical signals. In order for an organism to be fossilized, remains must be covered by sediment asap: exceptionally fast fossilization: freezing (permafrost), desiccation (desert), anoxic environment with slow bacteria which delays decomposition. Fossilization tends to favor organisms with hard body parts, widespread species, and those that existed for a long time before going extinct: very unlikely to find fossils of small soft bodied, geographically restricted and geologically ephemeral organisms.
