Stratigraphy, sedimentology and paleoenvironmental insights of upper Paleozoic glacigenic strata in Northern Victoria Land (Antarctica)

Late Paleozoic glacial deposits are widespread in the whole Gondwana, as well as in Antarctica, particularly in the Central Transantarctic Mountains and in Southern Victoria Land, whereas they are rare and very scattered in Northern Victoria Land, which represents a linkage sector with the Tasmania. The aim of the present short note is to show the stratigraphic setting and the environmental interpretation of a poorly studied Lower Permian glacigenic succession of Northern Victoria Land. Such succession, named here as Lanterman Tillite, lies directly on to the crystalline basement, and it is overlain by a thick fluvial succession Permian in age (Takrouna Fm.). The results provided by sedimentological facies analysis and palynological analysis, integrated by a brief petrographic characterization, show a correlation framework between two isolated successions, outlining their stratigraphic architecture subdivided in a lower glacial portion and in an upper postglacial portion. The former, Asselian in age, is dominated by diamictite, sandstone, mudstone with lonestone and carbonate deposits, suggesting repeated advance and retreat of a terrestrial glacier, with facies associations indicating environmental changes from subglacial to glaciofluvial, to glaciolacustrine. The latter is dominated by lacustrine mudstone with decreasing upward lonestones, thin bedded sandstone, conglomerate and a thick fluvial sandstone and pebbly sandstone portion at the top, reporting the transition to the above fluvial system. The overall dataset suggest that the studied Late Paleozoic glacigenic deposits of Northern Victoria Land record the evolution from a setting characterized by a terrestrial not wide ice cap that underwent repeated advances and retreats due to climate cold-warm cycles in a lacustrine setting, to a postglacial paleoenvironmental scenario with a wide fluvial system draining northward from Victoria Land toward the Tasman Basin.