GEOL 1001 : Geology Exam 3
Document Summary
Ch 10: principle of uniformitarianism, same physical processes observed today operated in past at roughly same rate responsible for formation of geologic features (james hutton, father of modern mythology) Geologic time- span of time since earth"s formation (4. 57 bya)/ deep time. Present is key to the past : geologic change is slow. Large changes large amounts of: numerical ages actual number of yrs since event (assigned, relative age- based upon order formation (older v. younger, two ways of dating geological materials. Fossils with relative age: fossil succession- fossil species occur in predictable order, fossil range first and last appearance, three types. Unconformity- time gap in rock record due to non-deposition or erosion: angular, nonconformity, metamorphic/igneous rock exposed, disconformity. Other numerical ages w/o isotopes: growth rings- annual layers from trees or shells, rhythmic layering- annual layers in sediments or ice. Geologic time scale: eons, hadean (4. 6 to 3. 8 ga bya)
