Earth Sciences 1022A/B Lecture Notes - Lecture 6: Paleomagnetism, Subduction, Oceanic Crust

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

Document Summary

Continental drift and paleomagnetism: magnetic studies of seafloor following ww2. Polar wandering million years show diverging paths: pole positions for north america and europe over last 500, poles might migrate only slightly, continents must have, divergent polar wandering paths show that continents drifted. Rigid plates: canadian j. tuzo wilson discovered that earth"s lithosphere is divided into several plates that gradually move relative to one another. Plate tectonics: lithosphere comprises 7 major plates; 7 major plates of rigid lithosphere ride on plastic asthenosphere; their interactions cause earthquakes, volcanoes, and mountain building, mainly at plate boundaries. Wilson) into segments: where plates slide past each other, cutting oceanic ridges, faults transform from being active between ridge segments to being inactive beyond ridge segments. Testing the plate tectonics model: other criteria to support plate tectonics theory. Hotspots: seamounts and volcanic islands can form a chain on a plate that moved continuously over a mantle plume, leaving a hotspot track of volcanoes.