Continental Drift / Pangea
Details:
Continental Drift refers to the horizontal movements of the continents in relation to one another. The mid-oceanic ridges (mountain chains running along the bottom of the ocean basins) continually produce molten lava. As new lava is produced, the older, solidified lava is pushed aside. This results in the ocean floor being pushed apart at right angles to the ridges. This is possible because, as shown by plate tectonic theory, the Earth's surface is composed of several rigid plates floating on a softer layer.
The theory of continental drift can be mainly attributed to the German meteorologist, [discovered by] Wegener*, who conceived of the idea of a single ancient proto-continent which broke up into pieces that drifted apart. He did so after observing the similarity in outline of the Eastern coastline of the South American continent and the Western coastline of Africa. When Wegener proposed his theory in 1912 it was rejected by geologists. However, mounting evidence (such as the disovery of similar fossil organisms on different continents) brought acceptance.
Oneliner: Continental drift
Bibliography:
- "Continental Drift"; Encyclopedia Britannica.http://search.eb.com/eb/article?eu-=26473; Accessed November 5, 2002.
- "Plate Tectonics"; Encyclopaedia Britannica.http://search.eb.com/eb/article?eu=115121; Accessed November 5, 2002.
Multimedia:
CONNECTIONS III #8 Fire from the Sky