explain why a super-continent form ,and why it would break up once it formed.?
155676
This is the Wilson Cycle, and it is driven by plate tectonics. \n\nContinents are composed of relatively light weight felsic igneous rocks such as granites and granodiorites. Ocean basins are composed of mafic igneous rocks like basalt and gabbro that are heavier than continental crust. Since the earth's mantle is plastic, these different masses of rock tend to 'float' at different levels. This is called isostacy.\n\nOceanic plate motion originates at the mid-ocean ridges, pushing oceanic plates outward towards the continents. This motion and force is far from being uniform from one ocean basin to another, and is not even consistent along the length of the mid-ocean spreading centers. \n\nWhere oceanic plates meet continental plates there is a convergent plate boundary and generally this leads to subduction of the oceanic plate. There is considerable force however, and the style of subduction does vary. Since the forces that are being applied, as well as the resistance of the continental plates all are varied, there are inequities that cause the continents to move in one direction. Eventually this motion results in a collision of continents called a supercontinent because continents will not subduct under one another. India and Asia, and the Himalayas are a great example of a continental convergent plate boundary. Eventually the convection forces that cause the supercontinent to form will begin rifting it apart again creating new smaller continents. \n\nHere is a model of the Wilson Cycle:\nhttp://csmres.jmu.edu/geollab/vageol/vahist/wilsonsimp.html
542027
Reminder: 5n Theory, all continents used to be attached to one another- so in theory this is highly possible- if two of every species has moved from place to place. Also remember, animals have a good sense of unusual events happening, like earthquakes and things, so they might have had the sense to know where to go. Then you might ask about the unicorns, but it is said that they were too stubborn to get on the ship... dragons and pegasuses... I have no idea about.
149639
The Himalaya's formed when the sub continent of India broke away from Gondwanalandand from memory approx 55 million years ago. Gondwanaland was comprised of the continents we now know as Antarctica, Australia, South America and Africa.  The Indian piece travelled north and collided with Asia ie where India now is.  This caused uplift of the collision forming the Himalaya's.  It is anticipated that Australia (which is drifting north at a rate of 13cm per year will eventually form part of mainland China.  It would be likely by that time that the Himalaya's would be considerably smaller due to erosion and the collision between Australia and China will create a new mountain range.
794138
The continental plates do not actually 'drift' as you may think of an ice cube 'drifting' in water. Nor are the plates all connected together like one would view a jigsaw puzzle.\n\nThe first idea you have to realize is that the continental plates overlap each other. The 'outlines' you see that appear jigsaw-like are more often than not areas where two plates meet, and one plate is actually going under  the one next to it- this is called 'subduction'.\n\nWhich plate goes under which plate depends on the age and weight of the plates-- continental crust is lighter than oceanic plate, so more often than not it is the oceanic piece of the plate that will 'subduct'.\n\nThere are areas, however, where the plates do actually meet like a jigsaw puzzle-- these places are known as "Strike-slip" faults, where two plates slide past each other rather than 'subducting'.\n\nAs for the plates moving, that happens due to the upper mantle (the liquid part under the crust) creating convective currents-- these 'currents of mantle material' cause the plates to move and subduct (or slide past each other!)\n\nAnd yes, there are plates where continental crust and continental crust meet. What happens then? More often than not, mountains form-- The Himalayas are a prime example of this situation (the Indian plate smashed into the Asian plate).\n\nThere's more to it, but I hope this helps a little bit!
38918
Mandy and Benny both have valid points. It's because of plate tectonics, because of which continents moved. Pangea (single continent) that existed millions and millions of years ago...slowly started dispersing and if you see the movement of india subcontinent, it moved all the way from southern africa and joined asian continent. This must have created a pileup of land that benny is talking about.
107934
The Earth's rocky outer crust solidified billions of years ago, soon after the Earth formed. This crust is not a solid shell; it is broken up into huge, thick plates that drift atop the soft, underlying mantle. \nThe plates are made of rock and drift all over the globe; they move both horizontally (sideways) and vertically (up and down). Over long periods of time, the plates also change in size as their margins are added to, crushed together, or pushed back into the Earth's mantle. These plates are from 50 to 250 miles (80 to 400 km) thick. \nThe map of the Earth is always changing; not only are the underlying plates moving, but the plates change in size. Also, the sea level changes over time (as the temperature on Earth varies and the poles melt or freeze to varied extents), covering or exposing different amounts of crust. \nThe current continental and oceanic plates include: the Eurasian plate, Australian-Indian plate, Philippine plate, Pacific plate, Juan de Fuca plate, Nazca plate, Cocos plate, North American plate, Caribbean plate, South American plate, African plate, Arabian plate, the Antarctic plate, and the Scotia plate.
122544
a traducir esta respuesta al español vaya a:\nhttp://babelfish.altavista.com/\n\nContinental drift is now referred to as Plate Tectonics. It is a well proven theory with multiple sets of observations that demonstrate that it is taking place today as you read this. The recent tsunami in Indonesia was an indirect result of plate tectonic movement that is taking place on the earth continuously. The Pacific Ocean is currently spreading by about 4 centimeters each year (about 2 inches). \n\nIf you examine the outline of many continents you will be able to see similarities in the shape, much like jigsaw puzzle parts that are not connected. South American and Africa are a good example of this. One interesting form of proof of the spreading that split South American away from Africa are oil reservoirs in West Africa and Brazil that have oil that is chemically and biologically identical. (All petroleum can be identified using special biomarkers and analyses as unique to its own source)  Since there is no way they could have migrated through the earth to these widespread locations, that oil must have been formed while Africa and South America were still connected. There are many more examples of biological organisms that are found on widely separated continents that are related. Another great example of this is that fossils found on Antarctica that come from tropical plants and wood show that that continent was once near the equator. Similar things can be found in northern Siberia, and northern Canada and Alaska. \n\nOther examples of this process and the jig-saw puzzle like pieces that have come together are many mountain ranges. In the high Sierra Mountains, above 10,000 ft elevations are deposits of marine limestone (now marble) that were once reefs on islands in the ocean we now call the Pacific Ocean. \n\nOver the past 250 million years a supercontinent called Pangaea has spread apart to the continents we know today. You can see a good illustration of this at \nhttp://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Pangea/Pangea4.html\nThat site has some good diagrams of Pangaea and how it has broken up and the plates have moved. It also explains the mechanism. \nHere is an animated version that shows the breakup:\nhttp://www.scotese.com/sfsanim.htm\n\nPrior to Pangaea, there was another supercontinent called Gondwana and another supercontinent called Laurasia combined with Gondwana to form Pangaea. Prior to the consolidation of Gondwana was another supercontinent called Rodinia. This supercontinent formation is apparently and hypothetically a cycle that the planet completes every few hundred million years, moving continents, building mountain ranges, and rifting other continents apart creating new oceans. \nOne of the best web sites on the internet that shows the various stages of the planet's plate tectonics is the Paleomap Project here:\nhttp://www.scotese.com/earth.htm\n Here is an illustration of Rodinia\nhttp://www.scotese.com/earth.htm\n Here is an illustration of Rodinia\nhttp://www.scotese.com/Rodinia3.htm\n\nSource(s):\n\nI'm a geologist.
475416
Nope; the oceanic plates are spreading apart, as new material (magma) is pushed up from below.  They are not crashing together at all.
536734
Alfred Wegener, German meteorologist, was gathering climate information with a partner when he started noticing glacial deposits that matched on different continents.\n\nThis led to more study of course. Why were similar deposits found in such far removed places?\n\nWhile looking into this, he also noticed that rocks & fossils on different continents were also identical.\n\nThis, along w/ the "continent puzzle" led to his hypothesis of continental drift. Notice, it is referred to as a hypothesis. This is because Wegener could never provide a driving mechanism for continental drift.\n\nWegener tried explaining how continents could move but to no avail. His explanation that the continental crust literally plowed through oceanic crust did not "cut" it. PUN intended. This was not possible w/o leaving torn crustal plates behind & there was no evidence of that.\n\nMost scientists rejected his hypothesis. Some, however, kept searching for the "driving mechanism" behind continental drift.\n\nIn 1968, scientists could finally provide this force behind the movement of the crust. It was named the theory of plate tectonics.\n\nThis theory stated that the earth's crust was broken down into many major & minor lithospheric plates. These plates moved due to uneven heating of the molten magma in the earth's mantle.\n\nConvection currents w/in the mantle are created by cooler magma sinking & hotter magma rising. As the hotter magma rises towards the asthenosphere, it will cool & then sink. This principle works in the same manner as it does in the atmosphere.\n\nPlates were either pulled apart at divergent boundaries or subducted at convergent boundaries unless it is at two continental convergent boundaries. In this case the two crusts are less dense than the magma below & will deform rather than be subducted.\n\nSo yes, Alfred Wegener did suggest the theory of continental drift. But it was not actually taken seriously until the theory of plate tectonics came along.
488071
At convergent plate boundaries two plates collide and the heavier of the two plates is forced beneath the lighter one. As the heavier plate gets pushed down deep into the earth it begins to melt and forms molten magma. This magma slowly migrates upwards through the earth's crust where it then errupts onto the earth's surface as lava, eventually forming volcanoes. \n\nAt divergent plate zones two plates move apart from each other. When this happens a crack forms in the earth's crust. Magma from below moves upwards into this crack to fill the void 'so to speak'. Once again this magma errupts onto the earth's surface as red hot lava and we have the formation of active volcanoes.
696568
They are results of the centrifugal and centripetal forces of the earth crust. This results faulting and folding of the earth's surface.
985501
Nice idea.... but there is a BIG hole in your theory:\n\nThe moon broke off from the earth somewhere between 3.5 and 4.5 billion years ago.... i.e. the Hadean... the more specific name for the earlier Precambrian.\n\nPangaea didn't even begin moving together until 1.1 billion years ago, and wasn't together as one continent until about 500 million years ago.... during the Permian.\n\nOh... and tectonic plate movement is a result of thermal flows in the mantle.\n\nPangaea has nothing to do with the moon, sorry to say.
268015
The matter that made up the sun and planets existed at one time as a very large disk. As the matter clumped together, it was already on the same plane. That's the theory, anyway.
735109
Mountains are formed in the process known as plate tectonics. The earth is made of 6 major plates which are located on the earths crust. below the crust is an area known as the mantle which is lava which is very viscous. The Mantle has whats know as convection currents. these are slowly spinning sections of the mantle. Some are spinning clockwise and others counter. During mountain building there are 2 plates, one on the are of the mantle which is spinning clockwise and another on the current which is spinning counter clockwise. This allows the 2 plates to move in opposite directions which are known as divergent boundary's. Some areas however and spinning in a way to allow the plates to push together known as convergent boundaries. When this occurs you get mountains forming because the 2 plates are pushing together with a lot of force and over millions of years you get mountains rising.
1163699
The continents we have now were mostly fused along their lower parts to each other in the distant past of Earth.\nOver millions of years they broke away and drifted apart. \nThe so called blunt part is that continent's ancient shores while the sharp part is a distant reminder of where they separeted.
556155
(m)\n\nAustralian and American researchers investigating forces exerted on the Indo-Australian tectonic plate have discovered that the considerable stresses being exerted on the plate could be leading to its breaking up.\n\nARC Professorial Fellow, Mike Sandiford, from the University of Melbourne’s School of Earth Sciences was recently awarded ARC funding for research aimed at understanding the forces that drive the motion of the Earth’s tectonic plates and the distribution of stresses in the Earth’s crust that give rise to great earthquakes such as the magnitude 9 Boxing Day Sumatran quake.\n\nProfessor Sandiford says the research shows that as much as 10 per cent of the huge amounts of energy being created at plate connection points at Sumatra and Java are being transferred back into our plate and causing major stresses.\n\n“This is enough stress to contribute to mild earthquake activity in the central regions of the plate, such as in the Australian continent or central Indian Ocean, and provides us with clues as to why our plate has been slowly breaking up,” he says.\n\n“The Indian Ocean quakes are, in effect, leading to the active rupture of the Indo-Australian plate into separate Indian and Australian plates. This new research provides us with important information about the stresses that are driving this drawn out tectonic plate divorce.”\n\nThe research, which was conducted in collaboration with Wouter Pieter Schellart of the Australian National University and David Coblentz of the Los Alamos National Laboratory in the US, will be published in the journal Geology (27 January).\n\nThe research is also important for understanding why smaller intra-plate earthquakes such as the 1989 Newcastle quake, which occurred nowhere near the edge of the plate, take place. Up to now, why earthquakes occur in apparently safe zones in the centre of plates has not been very well understood.\n\nProfessor Sandiford says, “Earthquakes such as the 1989 Newcastle quake that killed 13 people and caused more than $1 billion in damages are just one manifestation of mild tectonic activity that has been affecting the Australian continent for the last 5-10 million years.”\n\nThe new research shows that stresses originating at points of collision between two plates are being dissipated back into our plate and generating enormous internal stresses.\n\nThe ARC funded project will map the spatial and temporal pattern of this tectonic activity and relate it to the factors that drive the motion of the Indo-Australian plate.\n\n“This research will contribute to our understanding of the factors that drive plate motion, to earthquake risk assessment in Australia and other comparatively stable continental regions, and to the factors that have shaped our distinctive Australian landscapes,” he says.\n\nBACKGROUND INFORMATION\n\nWhat causes tectonic plates to move?\nThe Earth is made up of a series of layers. The outermost layer is called the crust and the innermost is the core. In between lies an area called the mantle (in turn made up of upper and lower mantle), which is arguably the most important when it comes to understanding where big earthquakes occur.\n\nThe outer part of the Earth, comprising the crust and top 100 or so kilometres of the mantle (together called the lithosphere), consists of a collection of eight major plates which almost fit perfectly together. The continents and oceans all lie on these plates, the major ones referred to as the African, Eurasian, Indo-Australian, Antarctic, Philippine, Pacific, Nazca, North American and South American, depending on their geographic location.\n\nThese plates (also referred to as tectonic plates) float on the softer mantle underneath. Convection currents within the upper mantle layer are a major driving force driving plate motion and therefore behind earthquake activity.\n\nThe lower sections of the mantle closest to the molten core of the earth are also the hottest parts of this la
640247
The plates consist of an outer layer of the Earth, the lithosphere, which is cool enough to behave as a more or less rigid shell. Occasionally the hot asthenosphere of the Earth finds a weak place in the lithosphere to rise buoyantly as a plume, or hotspot. \n\nOnly lithosphere has the strength and the brittle behavior to fracture in an earthquake. \n\nThe map below locates earthquakes around the globe. They are not evenly distributed; the boundaries between the plates grind against each other, producing most earthquakes. So the lines of earthquakes help define the plates: \n\n\nIn cross section, the Earth releases its internal heat by convecting, or boiling much like a pot of pudding on the stove. Hot asthenospheric mantle rises to the surface and spreads laterally, transporting oceans and continents as on a slow conveyor belt. The speed of this motion is a few centimeters per year, about as fast as your fingernails grow. The new lithosphere, created at the ocean spreading centers, cools as it ages and eventually becomes dense enough to sink back into the mantle. The subducted crust releases water to form volcanic island chains above, and after a few hundred million years will be heated and recycled back to the spreading centers.