Travel Reference
In-Depth Information
gle giant continental land mass at the end of the Permian Period, about 250
million years ago. And so they were.
The concept of continental drift was first given serious consideration
in the late nineteenth centuty, when the then-famous Austrian geologist
Eduard
Suess suggested that Africa, Madagascar, and India were once all
joined together as a single land mass and only later drifted apart. Suess based
this heretical proposal on the great similarity in the rock types found in all
three areas. He named this ancient continent Gondwanaland, borrowing
the name from an area in India inhabited by a tribe called the Gonds. Suess
was no charlatan or crackpot, and soon a few othet geologists, mainly those
working in the Southern hemisphere, began considering the possibility that
a "supetcontinent" existed there during the late Paleozoic and early Meso-
zoic Eras.
The various threads of evidence supporting the concept of an ancient,
southern supercontinent were woven together in a remarkable book published
by the German meteorologist Alfred Wegener in 1912. Wegener was con-
vinced that the similarity in coastlines between western Africa and eastern
South America went far beyond coincidence. He amassed paleontological and
geological information to support his cause, hut his book was met with instant
criticism. No mechanism for such "continental drift" could be postulated.
In the early 1900s a young South African geologist named Alexander
du Toit began to crisscross South Africa. He was to spend 20 years examin-
ing rock structure, mapping huge expanses of territory, and, in the process,
filing vast amounts of information away in his encyclopedic memory. Du Toit
soon realized that Wegener's outrageous hypothesis explained many of the
geological features of southern Africa, and in 1921 he published his first
paper about the possibility of "continental sliding." Geologists had long been
puzzled about the origin of the mountains rimming the South African coast-
line. Du Toit realized that they could have been compressed by continental
collision; he had a vision of southern Africa caught in a monstrous vice be-
tween South America and Antarctica. Du Toit was able to visit other south-
ern continents, where he observed remarkably similar successions of rocks. It
