Plate Tectonics free essay sample

Plate tectonics The large scale motions of the earth’s lithosphere are describe by a scientific theory called plate tectonics which explains that Earths outer layer is made up of plates, which have moved throughout Earths history. The theory was developed during first decade of 20th century (by a famous advocate Alfred Wegener) on the older concept of continental drift and was accepted by many geoscientific communities. There are currently seven major and many minor plates are present in the case of earth.These plates move in relation to one another at one of three types of plate boundaries:  convergent or collisional boundaries;  divergent  boundaries, also called spreading centres; and conservative transform  boundaries. Activities like earthquakes, volcanic activity, mountain building and oceanic trench formation occur along these plate boundaries and the lateral relative movement of the plates varies 0-100 mm annually. Relation between plate tectonics and mountains: Mountain formation processes are associated with large scale movements of tectonic plates. We will write a custom essay sample on Plate Tectonics or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The formation of mountain ranges occurs by means of lateral movements as opposed to vertical ones. Mountain formation is related to  plate tectonics, folding, faulting, volcanic activity; igneous intrusion and metamorphism are all parts of the organic process of mountains building. There are three main types of mountains: volcanic, fold, and block. Volcanic Mountains: movements of tectonic plates create volcanoes along the plate boundaries which erupt and form mountains.Around that time a super continent Pangea started split into different land masses and move apart in different directions. That result rivers Angara and Gondwana from the northern Eurasian land mass and the southern Indian land mass respectively started filling sediments into the shallow sea the tethys. as a result the two land masses moved closer and closer. About 70 million year ago the two land masses began to collide with each other started the initial mountain building process.The Southern Alps are tectonically characterised by large scale thrusting and folding to the south, the dominant direction of fold asymmetry in the region is southwards. . As is also the case in the southern foreland of the  Pyrenees, thrusts in the Southern Alps are oriented along listric fault  planes with relatively shallow  decollement horizons. To the west, south of the  Valle dAosta, the Southern Alps form a huge  monocline, up until the point that  mantle  material of the Apulian plate crops out in what is called the  Ivrea zone.The geological plate boundary under which Southern Alps lie is part of the pacific ring of fire, with the pacific plate in last 45 million years the collision has pushed up the thickness of rocks up a 20 km on the pacific plate to form the Alps. Uplift of the mountains has been fastest during the last 5 million years and still it is rising by the tectonic plates pressure. (ref:Wikipedia. org) The Andes: The Andes are a  Mesozoic  Tertiary organic  belt of mountains along the  Pacific Ring of Fire. Andes are the result of plate tectonic process caused by the subduction of oceanic crust beneath the South American plate.The main cause of the rise of the Andes is the compression of western rim of the  South American Plate  due to the subduction of the  Nazca Plate and the  Antarctic Plate. Geology of Andes: The origin of the Andes started with the Triassic when Pangea begun to break up and several rifts developed. The Andes took its present form by the uplifting, faulting and folding of sedimentary and metamorphic rocks of the ancient cratons to the east. The Andes has been rise under different degrees of tectonic stress, uplift and erosion that is why rise of the Andes was not constant.