Investigation into the Mawson Formation volcanics of southern Allan Hills and comparisons with northern Allan Hills and Carapace Nunatak

The thick, laterally continuous block-rich volcaniclastic layer of the southern Allan Hills area was examined to determine their source and mode of emplacement. Extensive geological mapping of the area was undertaken and a 1:20,000 lithofacies map of the Mawson Formation was compiled on the whole of the Allan Hills from its southern tip to Mt. Watters. Three stratigraphic sections were measured in southern Allan Hills covering the thick laterally continuous volcaniclastic layer with grain size, componentry, texture and structure recorded for each layer, to compliment the map. Four of the most prominent marker horizons (block rich layers) were followed laterally and every 50m the thickness of the layer and the size of the five largest clasts was measured to create isopach and isopleth maps to help identify the source of these layers. Environmentally significant features such as accretionary lapilli were mapped, described and sampled for further study. The volcaniclastic deposits of the northern Allan Hills region and Carapace Nunatuk were examined and compared with those of southern Allan Hills. At Carapace Nunatak, the carapace sandstone (a distal equivalent of the Mawson Formation) and the Kirkpatrick Basalt were examined and sampled. All basalt flows were sampled for a potential geochemical study.