Supercontinental Formation

This lab uses earthquake data to construct profiles of two convergent boundaries: the Tonga Trench and the Peru-Chile Trench. Where two tectonic plates converge, if one or both of the plates is an oceanic lithosphere, a subduction zone will form. When crust is formed at a mid-ocean ridge, it is hot and buoyant meaning it has a low density. As it spreads away from the ridge and cools and contracts, or becomes denser, it is able to sink into the hotter underlying mantle. When two oceanic plates collide, the younger of the two plates, because it is less dense will ride over the edge of the older plate. The density of the

Early scientist believed that one huge supercontinent existed over two hundred million years ago. The name for this supercontinent is Pangaea. Pangaea was broken in to several pieces, and each piece was a part of the lithosphere. They believed that the pieces of Pangaea formed the continents that we know of in present day geology. When Pangaea existed, the rest of the Earth was covered by an ocean called Panthalassa. Eventually, Pangaea split into two land masses, Laurasia to the north and Gondwanaland to the south. The theory of plate tectonics does in fact have an explanation for the movement of

The heavier oceanic plate is being pushed under and melted so that it will rise up the lithosphere as magma and gasses to cause an

Schulz’s article is split into five sections. The first section introduces the readers to Chris Goldfinger, a paleoseismologist at Oregon State University. Goldfinger was at a seismology conference in Kashiwa, Japan when the 2011 Tohoku

About 225 million years, all of the world’s land was contained in one supercontinent, named Pangea. This supercontinent would eventually separate itself into the continents that are known today, due to continuous movement of the earth’s tectonic plates, which led to major shifting and folding of the earth’s crust. This shifting formed many of the mountain ranges that exist today, such as the Appalachians and the Rocky Mountains. However, the time of Pangea’s separation into multiple continents and the time of the formation of the mountain ranges aren’t synonymous; for instance, the Appalachians were most likely formed before Pangea’s separation. About some 2 million years ago, a Great Ice Age befell the earth, which caused a

The western Cordilleran orogenic belt had been depicted as a passive margin after Neoproterozoic to Early Cambrian rifting. Afterwards, the passive margin converted to an active margin most probably about Late Devonian to Late Cretaceous through the subduction of the exotic allochthons beneath the North American plate. The late Jurassic to Cretaceous subduction of (Sevier and Laramide Orogeny) representing as a period of the back thrust, intraplate thrusting, behind a magmatic arc on the upper plate near or on its westernmost margin from the latest

Approximately, the world oceans were 100 to 200 meters (330 to 660 feet) higher in the Early Cretaceous period and 200 to 250 meters (330 to 660 feet) higher in the Late Cretaceous than the sea level of today. This major influence to the physical landscape resulted from increased volcanism due to the final breakup of Pangaea. The increase of global mid-ocean ridge volcanism helped to raise global sea levels by melting polar ice. This caused marine waters to inundate the continents, creating relatively shallow inland seas in North America, South America, Europe, Russia, Africa, and Australia. The surface area of the continents was greatly reduced. During the marine highstand – a time during which sea levels are at their highest – land covered only roughly 18 percent of the Earth’s surface, compared with 2 percent today. This occurrence in the Cretaceous period resulted in extensive formation of chalk and other marine limestone, a type of rock created under warm, shallow marine conditions. Due to the system’s thickness and relatively recent occurrence, Cretaceous rocks croup out in several locations around the

Starting with the subduction of the oceanic plate which is being dragged beneath the North American Plate. The weight of the water on the oceanic plates increases the density of the oceanic crust to the point where it get snagged underneath the continental crust. After years of being dragged under the North American plate, the Pacific plate fills with high amounts energy and tension to then

The three major types of tectonic plates are divergent, subduction and transform. Divergent plates tend to move apart from each other. Subduction plates are when oceanic plate moves under a continental plate. This can cause volcanos to erupt and large sized earthquakes. Transform plates slide back and forth against one another. The Lithosphere consists of the Earths crust and uppermost mantle. The North American plate and the South American plate are the major plates of the lithosphere. The lithosphere also consists of the Pacific plate, the African plate and the Eurasian plate. The Pacific plate is the only major plate that is mainly underwater and is also the largest plate in the lithosphere. The Earth was once one large continental body called Pangea, before the plates started

The earth has been through a lot of changes throughout time. It used to be thought that the continents were locked in their positions and couldn’t move, but in 1915 Alfred Wagner came up with a theory about continental drift (Tarbuck and Lutgens, 2015). While unsure of the process that happened at the time, Wagner also came up with the idea that all the continents in existence today were once all connected as one giant continent known as Pangea. This idea is supported by the findings of similar rocks or fossils in multiple locations separated by large water bodies. Thanks to more tools and funding, the oceanic ridge system was found and by 1968, the theory of plate tectonics was introduced (Tarbuck and Lutgens, 2015). This theory

The thicker sections fo the plates are the continents; the thinner parts make up the ocean beds. When two plates meet, the result is geologic upheaval on a vast scale. Such an encounter occurred about 20 million years ago in the region between North and South America. The Cocos Plate, a piece of the Pacific crust some 300 miles wide, moved eastward until it met the crustal plate underlying the Caribbean. The eastern edge of the Cocos Plate was driven beneath the western edge of the Caribbean Plate. As the Cocos Plate was forced downward, the friction, as well as the hear deep within the earth, liquefied its rock into magma, which found release by thrusting up in a chain of volcanoes. The volcanic islands that resulted formed a line of stepping-stones between the northern and southern

The seven major tectonic plates comprise mostly on continental plates and the Pacific plate. The seven major plates from greatest to least are called: the Pacific Plate stretching 103,300,000 km2, North American Plate being 75,900,000 km2, Eurasian Plate being 67,800,000 km2, African Plate stretching 61,300,000 km2, Antarctic Plate being 60,900,000 km2, Australian Plate being 47,000,000 km2, and the South American Plate being 43,600,000 km2. With different tectonic plates, there are different ways they can move: divergent, convergent, and transform. Divergent plate movement is when both plates moving away from each other, creating a canyon that has magma pushing out from the bottom, forming new ground. Convergent is usually an oceanic plate and a continental plate are moving into one another, causing the oceanic plate to subducts into the mantle. This causes move active volcanos and earthquakes. Even though all of the plates are in the lithosphere, it's only the where Earth is flexible enough to move rather than flow. The lithosphere flexes when loads of weight are placed on it or

The Rio Grande rift is superimposed on a region with a long and complex history of deformation and heating, which affects the location and com- position of the subsequent rift-related magmatism (Mack, Seager, Kieling, 1994).. The development of the Rio Grande rift formed part of a series of Cenozoic extensional events that affected the whole of the western USA. These events were contemporaneous with changes in motions of the Farallon and North American plates at the Pacific margin and are widely thought to be genetically related to them by processes such as back-arc spreading. Alternative hypotheses re- late extension to thermal relaxation and gravity spreading of Laramide thickened crust and magmatism to active asthenospheric upwelling.

It is said during the Archean period, the temperature of Earth was higher than compared to during the Wopmay orogen tectonism. This was the case because of the heavy, widespread and firm crust of the Earth. Likewise the Cordillera found in modern day west part of Canada, orogeny has three structurally

The large rift is a result of an immense geological event that produced large earthquakes and volcanic activity nearly 1 billion years ago. The event is a prime example of plate tectonic theory. Large plates along the mountains continually would shift allowing stratovolcano activity to persist.