Earth Sciences 1022A/B Lecture Notes - Lecture 1: Continental Shelf, Supercontinent, Convergent Boundary

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Stephen R Hicock

Document Summary

: geology (study of earth) is important for energy and natural resources, solving environmental problems, building cities and highways, predicting and protecting against natural disasters like earthquakes, volcanic eruptions, landslides, floods. Uniformitarianism: fundamental principle the present is the key to the past . : geologic time is measured in billions of years. Within disc, earth evolved through collisions of rocky and metallic fragments into rocky sphere divided into - dense core, large mantle, lighter crust. Nebula (cloud) of hydrogen and helium contracted under gravity into the flat disc of our solar systems. Crust and uppermost mantle formed rigid plates of Earthquakes, volcanoes, landslides) happen at plate boundaries, especially convergent boundaries. Plate tectonics: crust and uppermost mantle eventually split into rigid plates of lithosphere (sphere of rock) that move over earth"s surface above soft convecting asthenosphere (weak sphere) by continental drift, based on South america and africa fit well at 900m depth, which coincides with the edge of their continental shelves.