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Why was this theory rejected by the majority of earth scientists in the 's?
Almost everyone who has looked at a map of the world has noticed that the continents of South America and Africa seem to fit together fairly well. An even better fit is obtained if continental margins the underwater edge of the continent are used.
Other "fits" of this sort can be assembled as well. It is difficult to believe that this is purely accidental, yet it is equally difficult to imagine and support a theory that explains it.
It is one thing to notice a possibility and another to take it seriously enough to seek evidence to support the theory, but Alfred Wegener, a German meteorologist, decided to look for such evidence. Wegener carried out several successful expeditions.
He found fossil distribution patterns that were consistant between continents. He found that the species dispersed when the continents were connected and later carried to their present positions as the continents drifted apart. If the continents are reassembled into the supercontinent Pangea, the distribution of Glossopteris can be accounted for over a much smaller contiguous geographic area.
Also, Wegener theorized that if South America and Africa had been joined at some earlier time, there would be similar geological formations such as mountain ranges which would extend from one continent to another across the same boundry. Wegener proposed that three distinct layers occur at each of these localities.
The bottom, also the oldest, layer is called tillite and is thought to be a glacial deposit. The middle layer is composed of sandstone, shale, and coal beds. Glossopteris fossils are in the bottom and middle layers.
The top layer is the youngest and is made up of lava flows. These three layers occur in the same order in areas now separated by great distances of ocean.
Wegener proposed that these rock layers were made when all the continents were part of Pangea. Thus, they formed in a small contiguous area that was later broken and drifted apart.
Wegener also used the distribution of specific rock types to determine climactic zones in the geological past. For example, glacial till and striations scratches on the rockssand dunes, and coral reefs, indicate polar, desert, and tropical climates, respectively.
He used this information to find that, unlike the present distribution, in which zones parallel the equator, the past zones occupied very different positions. This implies that the rotational pole was in a different location relative to today. Wegener offered an alternative explanation.
He believed that the climate zones remained stationary and the continents drifted to different locations. The drift of the continents caused the apparent movement of the climate zones. Wegener's model was not accepted by all geologists.
Some thought that dispersion by winds or ocean currents could explain the fossil species being traced to where they were found. Other geologists thought the poles might wander and the continents remained stationary.Dec 02, · Granulomatosis with polyangiitis (GPA), formerly known as Wegener granulomatosis, is a rare multisystem autoimmune disease of unknown etiology.
Its hallmark features include necrotizing granulomatous inflammation and pauci-immune vasculitis in small- and medium-sized blood vessels (see the images below). Evidence of Continental As a meteorologist Alfred Wegener was well aware of some climatological puzzles, such as the remains of temperate climate trees that can be found under polar ice.
From this he began plotting world-wide distributions of both rock and . Drift” originated by Alfred Wegener. The development of the theory is an excellent example of the application of the newest rock is on the top and the rocks get older.
More Essay Examples on Earth Rubric. In , Wegener published this theory that a single continent existed about million years ago.
|What are You Studying?||His most notable work was the theory of continental drift. However his theory was highly controversial at the time as he had little evidence, but as technology enhanced neumerous discoveries were made which helped prove his idea of continental drift was true.|
He named his super-continent Pangaea, and maintained that it had later split into the two continents of Laurasia in the north and Gondwanaland in the south.
Alfred Wegener’s Biography - Alfred Wegener was born on November 1, in Berlin, Germany. Alfred Wegener was the youngest of five children to be born to Anna and Richard Wegener.
Alfred Wegener observed the apparent wandering of earth's magnetic pole. Wegener attributed this to the movement of the poles followed the approximate path of the movement of his continents.
Not only did this discovery provide evidence of continental drift, it also was an early example of the study of paleomagnetism.