What is Gondwanaalnd ?
Gondwana, also called Gondwanaland, ancient supercontinent that incorporated present-day South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica. It was fully assembled by Late Precambrian time, some 600 million years ago, and the first stage of its breakup began in the Early Jurassic Period, about 180 million years ago. The name Gondwanaland was coined by the Austrian geologist Eduard Suess in reference to Upper Paleozoic and Mesozoic formations in the Gondwana region of central India, which are similar to formations of the same age on Southern Hemisphere continents.
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Geographical Studies
The term Gondwana first used for a sequence of largely terrestrial rocks of Peninsular India ranging in age from the lower part of the Permiann to the mid-Cretaceous. Although ideas of drifting continents had been advanced earlier, it was not until late in the nineteenth century that geologists first suggested the existence of a large ancestral continent in the Southern Hemisphere in the geologic past.
Throughout most of the geologic time there were only two primordial continents: Laurasia in the north and Gondwanaland in the south separated by the Sea of Tethys. This hypothetical protocontinent termed Gondwanaland included present-day South America, Africa, Arabia, Madagascar, Ceylon, peninsular India, Antarctica, Australia, Eurasian regions south of the Alpine-Himalayan chain.
Throughout most of the geologic time there were only two primordial continents: Laurasia in the north and Gondwanaland in the south separated by the Sea of Tethys. This hypothetical protocontinent termed Gondwanaland included present-day South America, Africa, Arabia, Madagascar, Ceylon, peninsular India, Antarctica, Australia, Eurasian regions south of the Alpine-Himalayan chain.
About 265 million years ago, this continental togetherness began to split. For 200 million years, India, Arabia, and Apulia (consisting of parts of Italy, the Balkan states, Greece, and Turkey) drifted across the ocean, and finally collided with the rest of Eurasia some 65 million years ago. The collision uplifted the Alpine-Himalayan Mountain ranges extending from Spain (the Pyrenees) and northwest Africa (the Atlas) along the northern margin of the Mediterranean Sea (the Alps, Carpathians) into southern Asia (the Himalayas) to reach Indonesia. In spite of the great distance created by the continental drift, people have interacted, traded and migrated freely between the two regions overland and across the Arabian Sea and the Indian Ocean.
Because of its position in the reassembly, Antarctica must clearly play an important role in determining whether Gondwanaland actually ever existed. Despite its great importance to the concept, however, the geology of Antarctica was almost unknown when Gondwanaland was first postulated.
Because of its position in the reassembly, Antarctica must clearly play an important role in determining whether Gondwanaland actually ever existed. Despite its great importance to the concept, however, the geology of Antarctica was almost unknown when Gondwanaland was first postulated.
Theory of Continental Drift
The theory of continental drift apparently originated in 1858 with A. Snider (cited in Carozzi,1970), who observed that the shapes of opposing coasts of South America and Africa suggested that they were once joined. Much later, Taylor (1910) and Wegener (1912), from study of matching geo-logic features on now distant continents, concluded that the southern continents including India were probably once part of a supercontinent (now called Gondwanaland).
Full Case Study :
During the past quarter century, paleomagnetic data have slowly accumulated and gained reliability, and now also support the concept that dispersed pieces of Gondwanaland were once together (eg. Creer, 1965). It has only been within the past decade, however, that a tentative understanding has evolved of the way that the ocean floor spreads outward from mid-ocean ridges, thus providing a mechanism for moving the continents apart (eg. Heirtzler, 1968). The theory of continental drift, therefore, rests on similarities of coastlines; the matching of rocks by age, type, structure, and history; paleomagnetic data; and partial comprehension of the mechanism of sea-floor spreading. Throughout this long development of the theory, speculation concerning the place of Antarctica in Gondwanaland has increased, especially since the time of discovery of Gondwana rocks on the Antarctic Continent(Gould, 1935; Long, 1962).
Full Case Study :
During the past quarter century, paleomagnetic data have slowly accumulated and gained reliability, and now also support the concept that dispersed pieces of Gondwanaland were once together (eg. Creer, 1965). It has only been within the past decade, however, that a tentative understanding has evolved of the way that the ocean floor spreads outward from mid-ocean ridges, thus providing a mechanism for moving the continents apart (eg. Heirtzler, 1968). The theory of continental drift, therefore, rests on similarities of coastlines; the matching of rocks by age, type, structure, and history; paleomagnetic data; and partial comprehension of the mechanism of sea-floor spreading. Throughout this long development of the theory, speculation concerning the place of Antarctica in Gondwanaland has increased, especially since the time of discovery of Gondwana rocks on the Antarctic Continent(Gould, 1935; Long, 1962).
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