The history of continental drift. Maps of continental Drift 2019-01-17

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AP Biology, Chapter 25 The History of Life on Earth Flashcards

the history of continental drift

In this article, therefore, we shall examine the notion that the continents have shifted so far as we can do so without discussing the mechanisms of plate tectonics. They believed that the Earth was in the process of cooling and shrinking, which they used to explain the formation of mountains, much like wrinkles on a prune. He only understood his ocean floor profiles across the North Pacific Ocean after Bruce the Great Global Rift, running along the Mid-Atlantic Ridge. The concept of Pangea was first developed by German meteorologist and geophysicist in 1915. .

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Continental Drift

the history of continental drift

But that in itself was not enough to support his idea. Wegener's drift hypothesis also provided an alternate explanation for the formation of mountains orogenesis. Shortly before this had come one of the greatest mass extinctions of all time, the P-T event. Wegener's ideas were very controversial because he didn't have an explanation for why the continents moved, just that there was observational evidence that they had. Those endorsing the theory of intelligent design usually accept continental drift as well, but assert that a spiritual presence designed and created the earth.

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Continental Drift

the history of continental drift

Wegener concluded that they formed as a single mountain range that was separated as the continents drifted. Wegener then assembled an impressive amount of evidence to show that Earth's continents were once connected in a single supercontinent. Wegener discovered that the Appalachian Mountains of the eastern United States, for instance, were geologically related to the Caledonian Mountains of Scotland. This rifting is associated with volcanism and the formation of valleys, which have enabled preservation of early human fossils in Kenya and surrounding countries. Today glaciers only form on land and nearer the poles. Wegener's theory stirred considerable controversy during the 1920s. Even though the theory of plate tectonics is now widely accepted by the scientific community, aspects of the theory are still being debated today.

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continental drift

the history of continental drift

By 1967, barely two decades after discovery of the mid-oceanic rifts, and a decade after discovery of the striping, plate tectonics had become axiomatic to modern geophysics. The continental drift is the theory that once all the continents were joined in a super-continent, which scientists call Pangaea. After the war, Wegener returned to Marburg, but became frustrated with the obstacles to advancement placed in his way; in 1924 he accepted a specially created professorship in meteorology and geophysics at the University of Graz, in Austria. In 1596, Abraham Ortelius believed that the continents were drifted. If the recordings are reasonably dispersed, then the mappers can also plot the rotation of the land mass as it waltzes about the globe. Pangaea We have a bigger gap here. Finally, about 80 million years ago, North America separated from Europe, Australia began to rift away from Antarctica, and India broke away from.

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10 Facts about Continental Drift

the history of continental drift

Climatic patterns of the entire globe were affected by the presence of Pangea as well, since it stretched from far northern to far southern latitudes. The theory of continental drift was not generally accepted, particularly by American geologists, until the 1950s and 60s, when a group of British geophysicists reported on magnetic studies of rocks from many places and from each major division of geologic time. Wegener suggested that these creatures were alive in warm climate zones and that the fossils and coal later had drifted to new locations on the continents. In fact, plates moving together created the highest mountains in the world, the Himalayans, and the mountains are still growing due to the plates pushing together, even now, , according to. The theory has unified the study of the Earth by drawing together many branches of the earth sciences, from paleontology the study of fossils to seismology the study of earthquakes. Continental Drift Image Facts about Continental Drift 9: the presentation of hypothesis On 6th January 1912, Alfred Wegener was in front of the German Geological Society to present his hypothesis.

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Maps of continental Drift

the history of continental drift

As well mineral specimens along the supposed break lines of the continents are nearly identical. However, he had always been interested in geophysics, and also became fascinated with the developing fields of meteorology and climatology. Wegener discovered that South America, Africa, India, Australia, and Antarctica shared a suite of unique Mesozoic fossils, including a signature fern flora and several reptiles. Over millions of years the pieces separated, first into two smaller supercontinents during the Jurassic period, called Laurasia and Gondwanaland, and then by the end of the Cretaceous period, into the continents we know today. Other evidence gathered by Wegener included closely matching rock units shared by Africa and South America and geological evidence indicative of former equatorial climate belts and past glaciations that made little sense if the continents have always occupied the same positions. It is a constantly changing stage upon which this drama will be unfolded, and the scene-shifter in this great theatre is called continental drift. But gravitational measurements showed that many areas are not in isostatic equilibrium.


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Continental Drift

the history of continental drift

For the evidence that continental drift is happening,. It you put the compass on its side the dial slips off. He proposed two different mechanisms but each was weak and could be disproven. Set forth in 1912 by Alfred Wegener, a geophysicist and meteorologist, continental drift also explained why look-alike animal and plant fossils, and similar rock formations, are found on different continents. The concept was independently and more fully developed by in 1912, but his theory was rejected by many for lack of any motive mechanism. We may even be heading towards the creation of another supercontinent in another 75-80 million years due to the continued movement of the continents.

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AP Biology, Chapter 25 The History of Life on Earth Flashcards

the history of continental drift

But we can reconcile all these contradictory data with the hypothesis of continental drift. Searching for evidence to further develop his theory of continental drift, Wegener came across a paleontological paper suggesting that a land bridge had once connected Africa with Brazil. Thus, it is likely that the initial evolution and divergence of primates was closely linked with continental drift. Arctic Noun region at Earth's extreme north, encompassed by the Arctic Circle. It is now accepted that the plates carrying the continents do move across the Earth's surface, although not as fast as Wegener believed; ironically one of the chief outstanding questions is the one Wegener failed to resolve: what is the nature of the forces propelling the plates? For example: the similarity of southern continent geological formations had led to conjecture in 1889 and 1909 that all the continents had once been joined into a ; Wegener noted the similarity of Mantovani's and his own maps of the former positions of the southern continents. We could perhaps try to ascribe this to coincidence or to forces as yet unknown; but when we take this in conjunction with the rest of the evidence, it is more parsimonious to conclude that the Americas and the Old World were once contiguous, which entirely explains why the east coast of the Americas and the west coast of the Old World underwent the same geological processes.

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