Plate Tectonics Paper
University of Phoenix
Plate Tectonics Paper
Earthquakes, volcanoes, mountains and the Earth’s crust are unique yet have one common denominator; the amazing topic of plate tectonics. Plate tectonics has a place or specifically places a role in each of these natural wonders of the world. In the following, Team C will discuss the theory of plate tectonics and how the theory shaped the form and composition of the movement within the Midwest region of the United States. A discussion of various geological events and the types of rocks that formed because of these events will also be covered including the importance of the economic value of these rocks to the Midwest region of the United States. Theory of Plate Tectonics
According to Tarbuck and Lutgens (2006) the theory of plate tectonics is “the theory that proposes that Earth’s outer shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and the crust itself.” The theory was established in the 1960s and the 1970s as information was gained about the ocean floor, distribution of earthquakes and volcanoes, the interior of Earth and how heat is distributed, and the worldwide knowledge of plant and fossil distribution. The theory is based on Earth’s outermost layer, the lithosphere, and how this layer is broken into seven large plates. The plates include the African, North American, South American, Eurasian, Australian, Antarctic, and Pacific plates (COTF, 2005). The plates move in different directions and at different speeds sometimes crashing into one another. This crashing point is known as plate boundaries, and depending on how the plates meet or crash into each other depends on the type of plate boundary it is known by. Three specific types of plate boundaries exist; divergent boundaries in which plates move apart, convergent boundaries in which plates move together (one plate slides beneath the other) and transform fault boundaries in which plates grind or slide horizontally past one another (Tarbuck & Lutgens, 2006). Until recently scientists could not determine what drives the plate tectonics, though many theories have been discussed. One such theory is the Earth's mantle pushes the plates apart and heat rises upward and is deflected sideways, or the Earth's gravity pulls the older, colder, and thus heavier ocean floor with more force than the newer, lighter sea floor (Khara, 2010). Main Plate Tectonic Movement
One of the most notable aspects of the Mid-West area of the United States would be the New Madrid Seismic Zone that is made up of reactivated faults. These faults formed when what is now the North American continent began to split, or rift apart during the breakup of the supercontinent Rodinia during the Neoproterozoic Era, which was about 750 million years ago. Faults were then created along the rift and igneous rocks formed as magma was being pushed toward the surface. The rift system failed but has remained as an aulacogen (a scar or zone of weakness) deep underground. Another attempt at rifting occurred around 200 million years ago, creating additional faults, which made the area even weaker. The resulting geological structures make up the Reelfoot Rift, and are buried deep by younger sediments. The ancient faults however, appear to have made the rocks deep in the Earth's crust in the New Madrid area weaker than much of the rest of North America. Geological Events
The most notable geological events within the United States Midwest include the quakes of the New Madrid Rift Zone along the Missouri Bootheel. This fault line created what is believed to have been the largest earthquake to have hit the United States in modern history. The quake took place prior to the creation of the Richter scale but is thought to have measured eight or greater (Essortment, n.d.). The impact of the quake extinguished lakes and created new...