EESA06H3 Lecture 3: Lecture 3 Notes
Document Summary
What"s happening today is a guide to what has happened in the ancient past . We use clues from modern day to interpret ancient records (rocks) There are things that have happened in the past that haven"t happened in our time. Examples of processes: meteorite strikes (65 million years ago), supernova, supervolcanoes (yellow stone) Geological processes are operating on a timescale that we cannot comprehend. So a mix of uniformitarianism & catastrophism. Assumption that all activity goes on around plate margins. But you can interpret part of the history in what we call vertical tectonics. Huge amounts of magma arise from mantle and erupt on earth"s surface = large igneous provinces = They"re very important in canada economically contain a lot of gold. How continents break up and ocean forms. Modern oceans form narrow cracks called rifts, and then they widen to form young oceans. East africa: where geologists go to understand how ancient oceans opens.
