Lateral profiling of facies and sediments, and examination of trace fossils and altered Pivot Member sediments to describe the depositional environment of the quartzose sandstones of the Beacon Supergroup

The origin of quartzose sandstones in the lower part (Devonian) of the Beacon Supergroup, southern Victoria Land, has generated considerable debate. This project examined in detail the lowermost Beacon Supergroup, specifically the New Mountain Sandstone at Table Mountain. Data was collected by measuring (primarily describing facies and recording paleocurrent directions) closely spaced vertical stratigraphic sections and laterally tracing individual bedding units. Exposures at Table Mountain were ideal for lateral profiling techniques which take into account lateral as well as vertical facies changes in order to provide a refined depositional model to describe the depositional environment. Samples were taken for petrographic analysis. Trace fossils of the lower Taylor Group were described in detail. The Pivot Member contains fine grain sedimentary rocks that in places have been extensively altered to Fe-Ti minerals by hydrothermal fluids related to the emplacement of dikes and sills of the Ferrar Dolerite. Altered Pivot Member sediments were observed by reconnaissance of the Platform Spur area and Sickle Ridge. Sickle Ridge was not extensively altered by the intusive Ferrar Dolerite and therefore all occurrences of the Pivot Member are not significantly altered by Fe-Ti mineralisation. Samples were collected for analyses from Platform Spur.