This report contains an interpretation of the geological framework of the continental margin off the AAT based on data recorded by the Australian Antarctic and Southern Ocean Profiling Project in 2001 and 2002.

Northern Jetty Peninsula, incorporating Else Platform (~140 km2) and Kamenistaja Platform (~15 km2), represents a mostly ice-free low-lying region located on the western flanks of the Lambert Graben. The region is underlain by granulite-facies Proterozoic gneisses and unmetamorphosed Permian sediments. Metamorphic rock types include quartzo-feldspathic, pelitic and semi-pelitic metasedimentary rocks of probable Mesoproterozoic age (Kamenistaja Paragneiss and Else Gneiss). Minor intercalated ultramafic and calc-silicate bodies are also present. Neoproterozoic (ca. 940-1000 Ma) syn-tectonic felsic intrusives (megacrystic Chistoe Granite, Melkoe Granite and Soyuz Leucogranite) are also widespread. Proterozoic rocks are subsequently intruded by Paleozoic Jetty Granite Dykes and felsic Stagnant Pegmatites (ca. 500 Ma), alkaline mafic dykes (ca. 308-320 Ma) and Mesozoic alkaline stocks and pipes (ca. 130-150 Ma). The Toploje Member of the Amery Group (a sequence of Permo-Triassic fluvial siliciclastic rocks, which outcrop extensively on the southern and western flanks of Beaver Lake) is exposed on southwestern Kamenistaja Platform and appears fault-bounded against the high-grade Proterozoic rocks. Together with adjacent high-grade rocks in Kemp and Mac.Robertson Lands to the west, the rocks of northern Jetty Peninsula form part of an extensive Meso-Neoproterozoic high-grade mobile belt (the 'Rayner Orogeny'; ca. 900-1100 Ma). During this event, on Else Platform, peak metamorphic conditions reached pressures as much as ~6.5 to 7.5 kbar at temperatures ~ 800º C and resulted in the development of a pervasive gneissosity (the dominant form surface, S1). Localized high-strain zones (S2) developed during latter stages of the high-grade metamorphic evolution, conditions during which are estimated at ~5 to 6 kbar at temperatures ~ 700º C. The intrusion of north-trending Jetty Granite Dykes (and their subsequent deformation) at ca. 500 Ma occurred at probable upper amphibolite-facies, indicating that an early Palaeozoic event (which reached granulite-facies in Prydz Bay, ~ 200-300 km to the northeast) significantly affected the Jetty Peninsula region. Minor northwest-trending steeping dipping mylonites and vertical north-trending brittle faults cut all rock types, except the massive quartz 'blows' and veins. These quartz pods are locally abundant (e.g. near Soyuz station), and, together with the late brittle faults, are thought to be related to incipient rifting of the Lambert Graben during the breakup of Gondwana.

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 Protocol on Environmental Protection to the Antarctic Treaty (the 'Madrid Protocol') includes provisions to protect areas of biological, scientific, historic, aesthetic or wilderness value. While these provisions have been mostly utilised to protect sites of biological or cultural significance, sites of geological or geomorphological significance may also be considered. To date, only two sites within East Antarctica (Marine Plain, Vestfold Hills and Mount Harding, Grove Mountains), have been declared as Antarctic Specially Protected Areas (ASPA) in recognition of their unique geological or geomorphological significance. Recently, however, Stornes, a peninsula in the Larsemann Hills (Prydz Bay) has been identified as a candidate due to the abundance and diversity of extremely rare granulite-facies borosilicate and phosphate minerals found there. The need for proactive intervention, protection and management of sites of intrinsic geoscientific value is becoming increasingly important. This recent example highlights the growing awareness of the intrinsic scientific value of Antarctic geological features within the AAT, including rare mineral or fossil localities. This awareness is identified within the current Australian Antarctic Science Strategic Plan and emphasises that geosciences can actively contribute to and influence the development of management plans and actively support Australia's commitments to Annex V of the Madrid Protocol. Wider recognition of the geological values achieved by invoking the provisions for area management, including creating the need to obtain the permission of a national authority to enter the area, should also mitigate casual souveniring and accidental or deliberate damage caused by ill-advised construction or other human activity.

Antarctic ice shelves and fast flowing ice streams are key drainage features of the Antarctic Ice Sheet and their behaviour determines the sensitivity of the ice sheet to climate change and sea level rise. Some fast flowing ice streams are thinning rapidly and could be the 'soft underbelly' of the East Antarctic Ice sheet. Processes across the grounding zone are important in understanding the retreat behaviour of ice streams but are poorly understood because of the difficulty of accessing the region. The Antarctic Shelf preserves geomorphic features and sedimentary structures left by ice retreat which can provide insights into processes in and close to the grounding zone. Sidescan sonar records from Prydz Bay image a range of features that reflect changes in processes across the Amery Ice Shelf grounding zone during retreat after the Last Glacial Maximum. The major features identified are: Mega-scale Glacial Lineations Linear ridges of sediment formed by moulding of mobile subglacial sediment parallel to ice flow. Flutes and Mega flutes - Smaller linear ridges moulded by ice flow. Inter-flute dunes - Large bedforms formed by bottom currents flowing the grounding zone in the sub-ice shelf cavity. Transverse steps - Ice flow parallel ridges that terminate in steps running oblique to normal to the ice flow direction. Sinuous ridges (Eskers) - Gently sinuous ridges that run generally parallel to obliquely across fluted surfaces. Polygonal crevasse infills - Irregular polygonal ridges on the crest of grounding zone wedges. The presence of fluted and mega-scale glacial lineations indicates that the ice moved over an unfrozen, deforming bed in the zone up stream of the grounding zone. For most of the Amery Ice Shelf, the inter-flute dunes reflect strong thermohaline circulation in the ice shelf cavity. Sand and gravel recovered in cores from beneath the Amery Ice Shelf indicate significant current speeds, possibly enhanced by tidal pumping.

Drilling during Leg 119 (1988) and Leg 188 (2000; Sites 1165-1167) of the Ocean Drilling Program (ODP) provides direct evidence for long- and short-term changes in Cenozoic paleoenvironments in the Prydz Bay region. Cores from across the continental margin reveal that in preglacial times the present shelf was an alluvial plain system with austral conifer woodland in the Late Cretaceous that changed to cooler Nothofagus rainforest scrub by the middle to late Eocene (Site 1166). Earliest recovered evidence of nearby mountain glaciation is seen in late Eocene-age grain textures in fluvial sands. In the late Eocene to early Oligocene, Prydz Bay permanently shifted from being a fluvio-deltaic complex to an exclusively marine continental shelf environment. This transition is marked by a marine flooding surface later covered by overcompacted glacial sediments that denote the first advance of the ice sheet onto the shelf. Cores do not exist for the early Oligocene to early Miocene, and seismic data are used to infer the transition from a shallow to normal depth prograding continental shelf with submarine canyons on the slope and channel/levees on the rise.

Cold seeps and hydrothermal vents can be detected by a number of oceanographic and geophysical techniques as well as the recovery of characteristic organisms. While the definitive identification of a seep or vent and its accompanying fauna is seldom unequivocal without significant effort. We suggest an approach to identifying associated VMEs in the CCAMLR region that uses the results of scientific surveys to identify confirmed features while documenting a series of criteria that can be used by fishing vessels to reduce the accidental disturbance of seep communities.

An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Critical to this undertaking is understanding the distribution of benthic assemblages. Our aim is to identify the areas where benthic marine assemblages are likely to differ in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by known species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 30 types of geomorphic features of the seabed, 846 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of MPAs. We found that for existing MPAs no ecoregion has their full range of environmental types represented and 12 ecoregions have no MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 7 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 119 locations with spatially restricted environmental types, which should be considered for inclusion in future MPAs.

Dense coral-sponge communities on the upper continental slope at 570 - 950 m off George V Land have been identified as a Vulnerable Marine Ecosystem in the Antarctic. The challenge is now to understand their likely distribution. Based on results from the Collaborative East Antarctic Marine Census survey of 2007/2008, we propose some hypotheses to explain their distribution. Icebergs scour to 500 m in this region and the lack of such disturbance is probably a factor allowing growth of rich benthic ecosystems. In addition, the richest communities are found in the heads of canyons. Two possible oceanographic mechanisms may link abundant filter feeder communities and canyon heads. The canyons in which they occur receive descending plumes of Antarctic Bottom Water formed on the George V shelf and these water masses could entrain abundant food for the benthos. Another possibility is that the canyons harbouring rich benthos are those that cut the shelf break. Such canyons are known sites of high productivity in other areas because of a number of oceanographic factors, including strong current flow and increased mixing with shelf waters, and the abrupt, complex topography. These hypotheses provide a framework for the identification of areas where there is a higher likelihood of encountering these Vulnerable Marine Ecosystems.

To study the seafloor morpholofy on the George V land shelf, East Antarctica, over 2000 kilometres of high-frequency echo-sounder data were collected between February and March 2000. The acoustic facies are explained in terms of glacial and oceanographic influences on the shelf since the Last Glacial Maximum.