The Mac. Robertson Shelf and western Prydz Bay, on the continental shelf of East Antarctica, were the sites of seismic/coring programs in February- March 1995 and 1997, and of an opportunistic sampling in 1993. Seismic data indicate a prograding sequence, about 200 m thick, dominated by clinoforms, in Palaeogene sediment. Core sampling was accompanied by deployment of a conductivity/temperature/depth probe (CTD), bottom camera and bottom-sediment grab. The Palaeogene sediments overlie Jurassic-Cretaceous sediments or Precambrian basement, and are overlain by thin, olive-green Quaternary diatomaceous ooze and sand. Sampling from the walls and floors of valleys crossing the shelf was on targets defined seismically, and recovered: Weakly lithified black carbonaceous or brown mudstone and siltstone with Paleocene (P4 and Paleocene undifferentiated), Middle Eocene with Globigerinatheka, and other Palaeogene foraminiferid faunas; Paleocene and Eocene pollen, spores and dinoflagellates; Sediments containing a mixture of Palaeogene fossils and Pliocene to Late Pleistocene/ Holocene diatoms and foraminifera; and Evidence of recycling from Permian, Jurassic and Cretaceous sequences. The Palaeogene sediments from the Neilsen Basin and Iceberg Alley contain glauconite and pyrite (the former often, and the latter rarely, pseudomorphic after radiolaria) and, in places, abundant carbonised wood. Radiolaria, teeth and bone fragments are rare. Foraminifera are rare and very dominantly small and calcareous with very few planktonics. The rocks appear to be part of a coastal plain sediment sequence, all weakly lithified, which includes red muddy sandstone and the fossil-bearing lithologies. It is not clear if all the fossil material and enclosing sediments are in situ or have been reworked as fragments into later glacial sediments. The faunas all appear to have accumulated in an inner continental shelf, fully marine environment with temperate-climate water temperature, and where sediment input was high compared with biogenic carbonate production. Several depositional models meet these criteria. Palynology helps define Paleocene and mid-Late Eocene depositional events, the latter marked by the Transantarctic dinocyst flora. The marine Palaeogene can be related to depositional cycles well documented from other parts of the world.

With improving accessibility to Antarctica, the need for proactive intervention, protection and management of sites of intrinsic scientific, historic, aesthetic or wilderness value is becoming increasingly important. Environmental protection and management in Antarctic is unique globally and is managed by provisions contained within the Antarctic Treaty. Whilst these provisions have been primarily utilised to protect sites of biological or cultural significance, sites of geological or geomorphological significance may also be considered. However, in general, sites of geological and geomorphological significance are underrepresented in conservation globally, and, particularly, in Antarctica. Wider recognition of sites of Antarctic geological significance can be achieved by development of a geo-conservation register, similar to geological themed inventories developed elsewhere globally, to promote and recognise intrinsically valuable geological and geomorphological sites. Features on the register that are especially fragile, or otherwise likely to be disturbed, threatened or become vulnerable by human activity, can be identified as such and area management protocols for conservation, under the Antarctic Treaty, can be more readily invoked, developed and substantiated. Area management should mitigate casual souveniring, oversampling and accidental or deliberate damage caused by ill-advised construction or other human activity.

Video of the geo-heritage aspects of the rocks of Stornes Peninsula, Larsemann Hills

Data from surveys along the East Antarctic margin will be presented to provide insights into the diversity and distribution of benthic communities on the continental shelf and slope, and their relationship to physical processes. Seabed video and still imagery collected from the George V shelf and slope and the sub-ice shelf environment of the Amery Ice Shelf indicate that the benthic communities in these regions are highly diverse, and are strongly associated with the physical environment. Variations in seafloor morphology, depth, sediment type and bottom circulation create distinct seabed habitats, such as muddy basins, rugged slope canyons and scoured sandy shelf banks, which are, in turn, inhabited by discrete seabed communities. The infauna dominated muddy basins contrast sharply with the diverse range of filter-feeding communities that occur in productive canyons and rugged inner shelf banks and channels. In the sub-ice shelf environment, differences in organic supply, linked to the circulation patterns, cause distinct differences in the seabed communities. The strong association between benthic communities and seafloor characteristics allows physical parameters to be used to extend our knowledge of the nature of benthic habitats into areas with little or no biological data. Comprehensive biological surveys of benthic communities in the East Antarctic region are sparse, while physical datasets for bathymetry, morphology and sediment composition are considerably more extensive. Physical data compiled within the proposed network of East Antarctic Marine Protected Areas (MPAs) is used to aid our understanding of the nature of the benthic communities. The diversity of physical environments within the proposed MPAs suggests that they likely support a diverse range of benthic communities.

The Casey shallow-water near-shore seabed mapping survey (survey number GA-0348) was conducted as collaboration between Geoscience Australia (GA, Department of Science and Industry), the Royal Australian Navy (RAN, Department of Defence) and the Australian Antarctic Division (AAD, Department of the Environment). The survey was conducted as part of the ongoing AAD program Hydrographic Surveying and Bathymetric Data Acquisition (AAD 3326) and complements a previous charting survey to the Casey region undertaken by RAN and AAD (using the RAN vessel ASV Wyatt Earp) in 2013/14 (also conducted under AAD 3326). The purpose of the survey was to acquire geophysical, geological and biological data from the seabed environment in the shallow (<250 m) coastal waters adjacent to Casey station. The survey acquisition phase formed the main work program for the Antarctic Geoscience Program and Advice activity as part of the Marine Biodiversity and Antarctic Geoscience (MBAG) Section at Geoscience Australia during 2014/15. The shallow water marine environment around Casey station, East Antarctica, is a high use area in the Australian Antarctic Territory, and is frequently visited by the RSV Aurora Australis and smaller vessels conducting scientific research in the area, yet bathymetry data in the area is limited. Additionally, a long-term dive program has revealed the marine habitats in the area host globally significant levels of biodiversity, but this knowledge is geographically restricted in scope (i.e. shallow depths, close to shore). This biodiversity faces pressures from human activities and climate change, yet extensive knowledge gaps remain, limiting efforts to conserve and manage it effectively.

High-resolution marine sonar swath mapping, covering an area of ca. 33 km2 in the vicinity of the Windmill Islands (67° S, 110° E), Wilkes Land, east Antarctica, permits visualisation and description of the near-shore geomorphology of the seafloor environment in unprecedented detail and provides invaluable insight into the ice-sheet history of the region. Mesoproterozoic metamorphic basement exhibits prominent sets of parallel northwest-trending linear fault sets that probably formed during fragmentation of eastern Gondwana during the Mesozoic. The fault systems appear to control regional coastal physiographic features and have, in places, been preferentially eroded and exploited by subsequent glacial activity. Possibly the earliest formed glacially-derived geomorphological elements are networks of sub-glacial meltwater channels which are preserved on bedrock platforms and ridges. Subtle glacial lineations and streamlined landforms record evidence of the westward expansion of the grounded, Law Dome ice sheet margin, probably during the late Pleistocene Last Glacial Maximum, the direction of which coincides with glacial striae on onshore crystalline bedrock outcrops. The most striking glacial geomorphological features are sets of arcuate ridges confined mostly within glacially excavated `U-shaped valleys, exploiting and developed along bedrock fault sets. These ridge sets are interpreted as `push moraines or grounding zone features, formed during episodic retreat of highly channelised, topographically controlled ice-streams following ice surging, possibly in response to local environmental forcing during the mid-late Holocene. Minor post-glacial marine sedimentation is preserved in several small (1 km2) `isolated marine basins with shallow seaward sills.

Gravity data are presented for 220 sites covering 180 000 square kilometres in the Prince Charles Mountains area of eastern Antarctica. Bouguer anomalies range from +60 m Gal over the Amery Ice Shelf (near sea level) to -120 m Gal at altitudes above 2000 m on the Antarctic ice cap. Bouguer anomalies correlate with the mass per unit area above sea level in the relation expected for a region in isostatic equilibrium. Smoothed free air anomalies range from +60 to -60 mGal. North-south trending anomalies over the Lambert Glacier and Amery Ice Shelf are thought to be due to a major fault along the Lambert Glacier, and a rift structure under the Amery Ice Shelf. To the west of these structures the free air anomalies trend mainly east-west.

A helicopter survey has mapped gravity and magnetic anomalies and ice thickness over a 100 km by 100 km ice cap area, inland from coastal outcrops of Archaean and Late Proterozoic rocks of the Princess Elizabeth Land coast. The gravity and magnetic anomalies indicate that there is no major change in crustal structure across the boundary between Archaean and Lake Proterozoic rocks. The Archaean rocks of the Vestfold Hills do not extend further inland, but they may extend under Prydz Bay or as a narrow coastal strip under ice inland from the West Ice Shelf, 150 km to the northeast of the Vestfold Hills. Late Proterozoic rocks probably underlie most of the ice cap along the coast.

Highly magnesian (mg about 98) granulites, containing sapphirine, enstatite, spinel, phlogopite, and cordierite, occur as xenoliths in Precambrian orthopyroxene-bearing granitic rocks at Mawson and Gage Ridge, East Antarctica. At Mawson, a marginal reaction zone is considerably enriched in Fe, K, and volatiles H2O and F, largely at the expense of Mg, with the development of sapphirine + phlogopite-rich assemblages. At gage ridge, marginal gain of Fe and to some extent Ca and Na, and loss of Mg are indicated, but there was no significant gain of K or H2O, possibly because very low P(H2O) did not allow crystallisation of phlogopite. (Auth.)

The Archaean cratonic block of the Vestfold Hills, Princess Elizabeth Land is one of only three well-documented examples in East Antarctica. It is characterised by tectonically interlayered tonalitic to granitiC orthogneisses (Mossel gneiss) and garnetiferous paragneisses (Chelnok supracrustal assemblage) as well as sub- ordinate units of predominantly mafic granulite (Tryne meta-volcanics). This sequence is cut by a second suite of orthogneisses (Crooked Lake gneiSS), ranging in composition from gabbro-diorite to tonalite and granite, which was emplaced synchronously with the last major phase of deformation. Cutting the gneisses are several suites of Proterozoic tholeiitic dykes, including a high-Mg suite, which range in age from about 2350 Ma to 1300 Ma. Most dykes are unmetamorphosed, but, in the southwestern part of the VestfoldHills, high-pressure garnet-bearing assemblages developed during a late Proterozoic (about 1100 Ma) thermal event. Granulite facies gneisses that crop out southwest of the Vestfold Block, along the coast of Prydz Bay, show the regional effect of this younger metamorphism and form part of an extensive late Proterozoic high-grade terrain, which makes up much of the East Antarctic Shield. Gneisses in the Rauer Group of Islands, within 30 km of the Vestfold Hills, are lithologically similar (predominantly orthogneisses) to those of the Vestfold Block, and contain metamorphosed relics of Vestfold dykes; however, they include only a minor component derived by remetamorphism of Archaean continental crustal rocks. In contrast, gneisses further to the southwest were mainly derived from aluminous sedimentary protoliths, and are quite different in composition to those of the Vestfold Block and Rauer Group. They do not appear to have been intruded by mafic dykes (mafic granulite is very rare) and apparently represent a Proterozoic cover sequence of similar age to metasedimentary sequences in MacRobertson Land. Intrusion of locally fayalite- bearing granitic rocks took place about 500 Ma ago.