Earth Sciences 1022A/B Midterm: Lab Exam
20 Dec 2018
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Document Summary
Stratigraphy study of rock strata including their original succession, age relations, lithology, fossil content, form, distribution, and geologic history. Law of superposition younger sedimentary strata overlay older ones. Law of cross-cutting relations intrusive rock bodies are younger than the rocks into or between which they intrude. Laccoliths - blister like body b/n two layers of strata. Index fossils fossils representing a specific unit of geologic time: used to estimate the age of rocks according to the geologic time scale. Radiometric dating using the relative proportion of parent and daughter isotopes to determine the numerical age of geologic material. 14c, 87rb, 235u, 238u radioisotopes decay exponentials at a constant rate: half life the time required for one half of the original parent isotope to decay. Law of uniformitarianism processes that have shaped earth throughout geologic time are the same as those operating today. Law of original horizontality sedimentary layers are deposited horizontally but can then be tilted or folded during deformation.
