Geology GEOL-G 130 Lecture Notes - Lecture 3: Divergent Boundary, Relative Dating, Antarctic Circumpolar Current
Document Summary
After rifting stops, crust cools, only deep valley is left. Evidence for modern convergent vs. divergent boundaries: divergent: Evidence for past convergent vs. divergent boundaries: convergent. Age of rock may not equal the age of the mountain range: divergent. Geologic time: millions of years ago: relative dating. Oldest rocks are at the bottom of the pile. Works for sedimentary rocks: absolute dating. There are radioactive elements like uranium that are unstable and can change into another element. Uranium can change into lead which is a stable element. Half life/decay constant for an unstable element to a stable element is the time it took to transform one element into another. Granite can be dated using uranium to lead system. Time recorded in antarctic rocks: few rocks > 600 million years old, no rocks 180-25 million years old. Major changes and events in antarctic history: moving back through time.
