Earth Sciences 1022A/B Lecture Notes - Lecture 1: Geosphere, Hydrosphere, Convergent Boundary

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Hickock

Document Summary

Nebula: (cloud) of hydrogen and helium constructed under gravity into the at disc of our solar system. Crust and uppermost mantle formed rigid plates of : lithosphere that ride on the (crust and uppermost mantle, asthenosphere which moves by convection (underneath lithosphere moves & soft) caused by continental drift. Alfred wegner, 1920s: originally came up with the idea of continental drift. This theory was validated until after the second world war and after wegner had died. Pangaea started to break apart 170 million years ago. Most geologic activity (e. g. earthquakes, volcanoes, landslides happens at plate boundaries, especially convergent boundaries. Asthenosphere of the oceanic crust is convecting in a clockwise direction while the the continental crust is convecting counterclockwise called subducting. Subducting zone is the area in which one crust goes below the other. Is a cyclic type of pattern; example of one type of rock cycle. Can cause melting thereby creating more magma.