GEOL 101 Lecture Notes - Lecture 2: Geologic Time Scale, Phanerozoic, Uniformitarianism
18 Oct 2016
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Document Summary
Geologic time: relative age relationship can be determined through the superposition of layered rocks. Cannot determine the exact age, but can determine what is older/younger. Fossil biozonation: provides much higher resolution in age determination than seismic dating methods (more detailed) Biotic succession: as organisms change, it is irreversible; each species is unique to its time range, used for defining units of geologic time scale. Geologic time scale: precambrian - nearly 4 billion years before the cambrian period. Naming geologic time units the exact years. Fossils: record of the existence of an organism, typically occur in sedimentary rock with bones/skeletons when rapid burial occurs. Numerical age dating: done using the decay of radioactive decay of radiogenic isotopes, dating minerals is possible because they will generally not change isotopes , radioactive decay is a time-dependent process and is different for each element. Decay product - isotope resulting from the decay of the parent.
