5 October 2021Chapter 2: Earth ProcessesTectonic Processes:•Structure of Earth’s Interior:oCrust: Outermost layer of the Earth, divided into two types▪Continental Crust: Thick, composed granite, less dense than oceanic▪Oceanic Crust: Thin, composed of basaltic rockoMantle: “liquid” rock that movesoCore: Center of the Earth, solid, mostly made of iron and nickelTheory of Plate Tectonics:•Beginning: Alfred Wegner; German Scientist (Astronomer)oDefined the discovery of identical fossils of plants and animals, as well asmatching rock layers and land formations on various continents as continentaldrift.▪Continental Drift:The idea that continents can move over Earth’s surfaceoProposed that these items matched because of the land was once touchingoWegner proposed that the visible land was once connected▪Named this landmass “Pangea”▪Theorized that, over millions of years, the landmass drifted apartoUnfortunately, his theory was not well received▪Reason: Lacked scientific evidence of a mechanism that would move thecontinents•1960: Wegner’s Theory of Continental Drift was revised due to the Discovery of SeaFloor SpreadingoThe outermost layer of Earth’s crust (lithosphere) is made up of many differentplates calledtectonic platesoThese plates float on top of the nearly liquid (molten rock/magma) asthenosphereoMove via naturally occurring convection currents in the mantleoMovements of the plates cause various boundaries and features from continent tocontinentEvidence:•Sea Floor Spreading:oIs at the ocean ridge that new earth forms
