Antarctica and Gondwanaland

Abstract

Antarctica was probably first sighted about 1820 from ships sailing near the tip of the Antarctic Peninsula; this discovery confirmed the long-suspected existence of a southern polar continent. Rock exposures comprise less than five percent of the area of the continent, and those in East Antarctica occur in an oval belt that includes the coastal region and the Transantarctic Mountains. The major tectonic units of Antarctica are the East Antarctic shield, four orogens in the Transantarctic Mountains and West Antarctica, and a Cenozoic volcanic province. The delineation of these tectonic provinces allows a major test of the Gondwanaland hypothesis, the geologic compatibility of the opposing coasts. In fitting Antarctica into his Gondwanaland reassembly, Alex L. Du Toit had to depend largely on the shape of the continent because so little was then known about its geology. Since that time, progress in antarctic geology has yielded a number of discoveries that bear on the Gondwanaland problem.