In 1965 the ideas of continental driftand seafloor spreadingwere integrated into the overriding concept of plate tectonics, primarily by the work of John Tuzo Wilson, a geophysicist at the University of Toronto.Main points of the Plate Tectonics theory include:Earth’s outer layer is divided into many lithospheric platesEarth’s plates float on the asthenospherePlate movement is powered by convection currents in the asthenosphere at seafloor spreading centers, and the downward pull of a descending plate’s leading edge at subduction zones.
A Synthesis of Continental Drift and Seafloor Spreading Produced the Theory of Plate TectonicsWhere does the heat within Earth’s layers come from?Heat from within Earth keeps the asthenosphere flowing. This allows the lithosphere to keep moving. Most of the heat that drives the plates is generated by radioactive decay, given off when nuclei of unstable elements break apart.(Left) The tectonic system is powered by heat. Some parts of the mantle are warmer than others, and convection currents form when warm mantle material rises and cool material falls. Above the mantle floats the cool, rigid, lithosphere, which is fragmented into plates. Plate movement is powered by gravity: The plates slide down the ridges at the places of their formation; their dense, cool leading edges are pulled back into the mantle.
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Plate Tectonics could explain:Pattern of paleomagnetismPattern of earthquakes and volcanic activitiesPattern of sedimentationAge of continents and oceanic crustOcean depth increases away from the mid-ocean ridgeShape of coastlinesFossil recordsHot spotsAtoll and guyots