PHYS 037 Lecture Notes - Lecture 17: Mesozoic, Symbiogenesis, Devonian
6 Dec 2016
School
Department
Course
Professor
Document Summary
Age measurement: fossils, paleontology, most fossils are traces of organisms embedded in sediment. Produced by weathering and erosion of rocks. Sediment becomes a recognizable stratum in the stratigraphic sequence. Strata of the same age tend to contain the similar fossil assemblages (index fossils) that can be used for relative dating fossils despite upheavals (relative dating) This helps geologists determine relative dates of embedded: absolute dating assigns an actual date to a fossil, one absolute dating method relies on radiometric dating, half life techniques. Length of time required for half of the atoms to change into. All radioactive isotopes have a dependable half-life another stable element: some only fractions of a second, some billions of years, most in between them useful over all periods of interest. Many isotopes are used, and their combined half-lives make. Geological timescale: divides history of the earth into, derives from accumulation of data from the age of fossils in strata, life arose during the precambrian.
