Russian Journal of Earth Sciences
Vol. 4, No. 4, August 2002
Tectonic structure and evolution of East Antarctica
in the light of knowledge about supercontinents
G. E. Grikurov and E. V. Mikhalskii
Abstract
This paper is based on the study of the new geological,
isotopic, and geochemical data that were obtained in the last years
on the igneous and metamorphic rocks of East Antarctica, dated from
Late Mesoproterozoic to Early Paleozoic. This period of its
geological history is believed, based on plate-tectonic
paleoreconstructions, to include, first, the origin and breakup of
the hypothetical Rodinia Supercontinent and, later, the formation
of a new supercontinent, Gondwana. Our review and critical study of
extensive foreign literature, as well as the results of our own
field and laboratory studies of crystalline rocks from the East
Antarctica crystalline basement, suggested a different idea: the
supercontinental lithospheric block, including the continents of
the Gondwana group, had remained intact throughout the Proterozoic,
and perhaps throughout the whole of the Precambrian. Intensity-variable
extension pulses, which acted on that primary continental
lithosphere, might have caused the origin of some local ocean
openings, yet did not result, up to the end of the Mesozoic, in the
complete breakup of this sialic megablock with any large-scale
spreading development.