EESA06H3 Chapter 19: Chapter 19 Textbook Notes.odt
Document Summary
Geoscientists working the field are usually concerned with relative aging. Glacial sediments on top are younger than the surface that they cover. Isotopic dating allows us to find absolute age. Through isotopic dating we have discovered that rocks of the north american craton range in between 4 billion and 1 billion years old. So almost close to the age of the earth (4. 56 ma) Determining age relationships between geographically widely separated rock units is necessary for understanding the geologic history of a region, continent, or the whole earth. Proving the plate tectonics theory requires evidence that the continents were once one great body this can come from correlation of rock units. Discovery of fossils in strata this helped geologists identify stratigraphic successions and eventually allows the creation of the standard geologic timescale. Isotopic dating has allowed for the addition of specific ages (million, billion) to each time period.
