SEDIMENTARY ENVIRONMENTS OF THE LATE PALEOZOIC ICE AGE DEPOSITS, NORTHERN VICTORIA LAND, ANTARCTICA: PROVENANCE AND PALEOGEOGRAPHIC IMPLICATIONS

The Earth saw numerous ice ages throughout its history. The Late Paleozoic Ice Age (LPIA) is known as the first ice age after the Earth had established its elemental cycling system as it is. The Gondwana, including Antarctica, was located in the southern hemisphere and existence of ice sheets or patches were known from the glacial deposits formed under effects of the glaciers. Changes in distribution and extent of the LPIA deposits were regarded as a proxy for waxing and waning of the ice sheets in the southern hemisphere, which has been understood as one of the main engines driving environmental changes in the late Paleozoic. The LPIA deposits in the northern Victoria Land (NVL), Antarctica occur in the lower part of the Beacon Supergroup and are characterized by disorganized mud-matrix conglomerates, cross-stratified sandstones, thin-beds of normally graded sandstones, and dark gray mudstone containing dropstones. The Lanterman and Neall Massif tillites are the northernmost LPIA deposits of Antarctica and hold importance as they are situated in the middle of the Transantarctic Mountains and Australia which are locations of major glacially influenced sedimentary basins. Recent comprehensive sedimentological and stratigraphical studies on the LPIA deposits of NVL revealed that they were formed under glacio-lacustrine and fluvial environments, with sediments primarily coming from the south. This suggests that there might have been a geographical high that separated NVL from Transantarctic Mountains. This further suggests that the NVL LPIA basin was rather connected to that of Tasmania which was located in the north of NVL during that time. The detailed research on the NVL LPIA deposit will provide basic data for integrated understanding of environmental changes in Antarctica-Australia transactions and the global responses to them.