The Heimdall Erosion surface

The Heimdall Erosion surface between Mt Jason, Mt Hercules, Mt Electra, Balham Valley, Vashka Lake and Sponsors Peak was investigated with the aim to evaluate the tectonic setting of early Beacon sedimentation, see what changes in environment and tectonic setting took place at the erosion surface, whether changes in provenance could be detected and what the tectonic driver for the formation of the surface was. The Heimdall Erosion Surface is a feature which divides the Taylor Group (lower part of the Beacon sandstones) into two subunits. It is a major stage in the development of the Ross Sea Region. In Devonian times, the Taylor Group basin lay within the combined Australia-Tasmania-New Zealand-Antarctic continental assembly. The question of why the basin was initiated and how its seemingly passive subsidence related to the contemporaneous vigorous activity in adjacent areas was investigated. Sections through the upper part of the New Mountain Sandstone and the lower part of the Altar Mountain Formation was measured Samples of sandstone materials were collected for U/Pb geochronology. Trace fossils were studied as an index of environment to support data from sedimentary structures.