Building the Case In spite of all the criticism, Wegener was able to keep Continental Drift part of the discussion until his death. He knew that any argument based simply on the jigsaw fit of the continents could easily be explained away.
It is thought that all the continents were once joined together in one super-continent, named Pangaea. Due to the inadequately explained geologic forces causing upwelling of molten material, Pangaea split apart into the major continents we have today.
The upwelling material was thought to be a result of convection forces within the earth. This material reached the surface at oceanic ridges and returned to the earth at subducting oceanic trenches.
Up until recently this theory was thought to be very controversial and was largely rejected because of an inadequate explanation for the forces required to move the continents. But the overwhelming evidence indicates the continents are moving and were at one time joined together in some fashion.
It is the objective of this paper to prove this theory. Wegener was also intrigued by the occurrences of unusual geologic structures and of plant and animal fossils found on the matching coastlines of South Essay theory of continental drift and Africa, which at present is widely separated by the Atlantic Ocean.
He reasoned that it was physically impossible for most of these organisms to have swum or have been transported across the vast oceans in the prehistoric eras. But to him, it was the presence of identical fossil species along the coastal parts of Africa and South America which to him was the most compelling evidence that the two continents were once joined.
Other mismatches of geology and climate included distinctive fossil ferns discovered in now-polar regions, and the occurrence of glacial deposits in present-day arid Africa. As he expected, his proposal was not well received, even though it seemed to agree with the scientific information available at the time Oreskes, N What kind of forces could be strong enough to move such large masses of solid rock over such great distances?
The idea of continental drift did not become widely accepted even as theory until the late s. By the s, geological research conducted by Robert S.
Dietz, Bruce Heezen, and Harry Hess, along with a rekindling of the theory including a mechanism by J. Tuzo Wilson led to widespread acceptance of the theory among geologists. The continents look as if they were pieces of a giant jigsaw puzzle that could fit together to make one giant super-continent.
For example; The bulge of Africa fits the shape of the coast of North America while Brazil fits along the coast of Africa beneath the bulge. Figure 1 shown the earth at approximately million years ago, the Permian period. Take note that the continents fit like a jigsaw puzzle.
The Permian Period Figure 2 shows the earth at approximately million years ago, the Jurassic period. Note that the continents have started to seemingly drift apart still revealing the areas where the jigsaw puzzle used to snugly fit.
The Jurassic Period Figure 3 is the earth at the present day period. Still oceans apart, one may still see the shapes of the continents resembling the original jigsaw pieces, only this time, distorted.
Wegener noted that plant fossils of late Paleozoic age found on several different continents were quite similar. This suggests that they evolved together on a single large land mass. He was intrigued by the occurrences of plant and animal fossils found on the matching coastlines of South America and Africa, which are now widely separated by the Atlantic Ocean.
He reasoned that it was physically impossible for most of these organisms to have traveled or have been transported across the vast ocean. To him, the presence of identical fossil species along the coastal parts of Africa and South America was the most compelling evidence that the two continents were once joined.
Ice and Rocks Match: The findings of rock belts in Africa and South America are the same type.
These broad rock belts found at the end of these continents are matched when joined together. Wegener was aware that a continental ice sheet covered parts of South America, southern Africa, India, and southern Australia about million years ago. Glacial striations on rocks show that glaciers moved from Africa toward the Atlantic Ocean and from the Atlantic Ocean onto South America.
If the continents were cold enough so that ice covered the southern continents, why is no evidence found for ice in the northern continents? The present northern continents were at the equator at million years ago.Continental Drift and Plate Tectonics Essay.
Continental Drift and Plate Tectonics Theory (Part 1a) Introduction: The Beginning of the “Continental Drift Theory” In the middle of the eighteenth century, James Hutton proposed a theory, uniformitarianism; “the present is the key to the past”.
key words: Continental Drift, Scientific Theory, Plate tectonics In , a scientist by the name of Alfred Wegener proposed the continental drift theory. The idea that the continents are continuously moving either towards or away from each other.
Continental drift is the theory that the positions of the earth's continents have changed a lot through geologic time. The German meteorologist Alfred Wegener proposed the first comprehensive theory of continental drift in , on the basis of the way the continents fit together on the opposing Atlantic coasts and paleontology correlation on both sides of the Atlantic.
Based on the theory of continental drift, Wegener began to gather evidence from around the world from landforms, fossils, and climate and put it in a book titled “The Origin of Continents and Oceans,” which was published in Continental Drift and Plate Tectonics Theory (Part 1a) Introduction: The Beginning of the “Continental Drift Theory” In the middle of the eighteenth century, James Hutton proposed a theory, uniformitarianism; “the present is the key to the past”.
Continental drift is defined as the motion of the earth’s continents over a defined period of time - Evidence of the Continental Drift Essay introduction. The theory of continental drift was first proposed by Alfred Wegener in