Tectonic Plates and The Plate Tectonics Theory essays

Tectonic Plates and The Plate Tectonics Theory essays For millions of years, tectonic plates have been determinate of changes in the physical face of the earth, and they continue to do so today. These massive plates move underneath the surfaces of the oceans and the continents, producing earthquakes, volcanoes and uplifts. This paper will discuss the composition, movement and history of tectonic plates, the theory of plate tectonics and its history, and tectonic plates affect the surface of the earth today and will continue to do so in the future. The earth is divided into three main layers: the core, the mantle and the crust. The core is further divided into the solid inner core and the liquid outer core. This layer is mostly iron and nickel and is extremely hot. The mantle is divided into the lower and upper mantle and is composed mostly of iron, magnesium, silicon, and oxygen. The outermost layer, which contains all life on earth, is the crust. This layer is rich in oxygen and silicon as well as aluminum, iron, magnesium, calcium, potassium, and sodium. It is in between the crust and the mantle that we find tectonic plates. The outermost layers of the earth are divided into two categories based on their physical properties. The asthenosphere is the lower of these categories, composed of clastic or flowing mantle. The upper layer is known as the lithosphere and contains both the top, rigid layer of the mantle and the crust. The lithosphere is what makes up the tectonic plates. The composition of these plates is b ased on their location. Plates under the surface of the ocean are made of mostly of basalt, while continental plates are comprised of rocks such as andesite and granite. It is generally believed that there are 12 plates that make up the earths surface. The majority of these plates are a combination of oceanic and continental lithosphere, while the Nazca, Pacific and Juan de Fuca Plates are made up of mostly oceanic lithosphere. Most of the continents ha...