GEO 303 Study Guide - Midterm Guide: Seismometer, Curie Temperature, Animal
Document Summary
Can be divided into two categories: body and trace. Trace fossils: something else the organism left behind, i. e. tracks, eggshells, feces, etc. Total preservation : preserves more than bones or exoskeletons, but not necessarily the soft organs ( think - organisms in amber! ) Step 1 of fossilization: permineralization , pores are filled with minerals. Step 2) complete replacement , in which the hard material is turned into by percolating (filtering) water minerals ( think - petrified wood! ) Mold/cast : molds are when an organism is buried and dissolves away. Casts are when the shell of an organism dissolves and the gap fills up with sediment. Compression : a preservation of soft materials in which only an imprint is left. Bias : fossil collection does not represent the types and abundances of organisms in the ancient ecosystem materials in which a carbon film remains. Natural bias : anatomy, depositional environment, and geological history.
