The Geology of the Queen Alexandra Range, Beardmore Glacier, Ross dependency, Antarctica;; with notes on the correlation of Gondwana sequences

Abstract

A preliminary account is given of the geology of the Queen Alexandra Range flanking the west side of the Beardmore Glacier in the southern part of the Ross Dependency. The basement rocks in the northern part of the range are strongly folded, late Precambrian greywackes and phyllites intruded by post–tectonic plutons of microcline–biotite granite. Cambrian limestones and conglomerates containing Archaeocyathinae crop out as a basement inlier at the Buckley nunatak at the head of the Beardmore Glacier. The basement rocks were peneplaned in the Early Paleozoic and covered by at least 7,000 ft of continental sediments of the Beacon Group of Gondwana age. Basal quartz arenites of Carboniferous and/or Devonian age are overlain by early Permian tillite, fluvioglacial sandstone, and dark shales, followed by Lower Permian coal measures with the Glossopteris flora. An Upper Permian –Triassic alternating sandstone–siltstone sequence overlies, capped by basaltic lavas. The Beacon sediments are extensively intruded by dolerite sills. Columns are presented showing provisional correlation of the Beacon Goup of East Antarctica with Gondwana rocks of Eastern Australia, Central India, South Africa, Falkland Islands, Brazil, and Argentina. Stratigraphic, floral, and faunal similarities between Antarctica and other southern continents show that Antarctica can truly be considered a part of “Gondwana–land.”; Paleoclimatic evidence is used to test the paleogeographic reconstructions of supporters of the Continental Drift Theory. The report is accompanied by a geological map on a scale of about 10 miles to an inch.