This report describes the results of geomagnetic measurements made at repeat stations in the northern Prince Charles Mountains (PCMs) in January 1992 and at Heard Island in February 1992. The PCM survey covered 7of the 9 stations occupied by Crosthwaite in Jan/Feb 1990. The Heard Island work was a reoccupation of a previous magnetic station and observatory site. Multiple sets of DIF or HDF observations were made at each station and sunshots, pier differences and local F surveys were carried out at most stations for confirmation of the 1990 measurements. Variometer records for the 3-5 day occupation of each station were obtained using two portable fluxgate magnetometers developed by F Chamalaun, Flinders University. One was left installedat the first repeat station, the other was carried and reburied at each repeat station. The area covered by the survey was approximately 160 km by 130 km. Station descriptions based mainly on those provided by Crosthwaite are included to facilitate reoccupation. References to earlier geophysical and surveying occupations are given in Crosthwaite (1992).

The Rayner Complex of East Antarctica is exposed between 45??80?E in the Enderby Land through Princes Elizabeth Land sector of East Antarctica. It is known to correlate with parts of present day India and to have been deformed and metamorphosed at high grades in the earliest Neoproterozoic (990-900 Ma). The age and origin of the protolith rocks of the Rayner Complex however remains largely unknown, as does the tectonic setting in which these rocks formed. New age data collected from the northern Prince Charles Mountains (eastern Rayner Complex), demonstrate that the pre-orogenic rocks from this region consist of: (1) volcanogenic and terrigenous sediments deposited between 1400 Ma and 1020 Ma in a magmatically active basin characterised by limited input from cratonic sources and, (2) probable syn-sedimentary granitoids dated to 1150 Ma. Our data confirm the continuity of the Rayner Complex into Prydz Bay, a region that preserves a remarkably similar geologic history but which is often differentiated from the Rayner Complex on the basis of a higher grade early Cambrian (~520 Ma) overprint. On the basis of our data we further conclude that the Rayner Complex protoliths likely in formed in a back-arc system that existed along the margin of the pre-Gondwana Indian craton. Anticlockwise P-T paths and high-T, low-P metamorphism associated with the inversion of the Rayner back-arc (990-900 Ma) suggest this event resulted from the accretion of a number of independent microplates, rather than continent-continent collision.

The Australian Antarctic Expedition 1911-14 established four absolute magnetic stations, namely Stations A, B, C and D. Two subsequent stations, Stations E and F, came into operation in 1950 and 1952 respectively. Because absolute magnetic observations had been made at different stations is was essential that the differences in the magnetic elements between the various stations be determined so that all data could be reduced to a common point. The observations were carried out during the period 31st March to 6th April 1952, whilst the Australian National Antarctic Research Expeditions relief operations were in progress.

Ecoregions are defined in terms of community structure in function of abiotic or even anthropogenic forcing. They are mesoscale structures defined on the potential habitat of species or predicted communities geographic extent. We assume that they can be more easily defined for long-lived species such as benthos or neritic fish in the marine environment. Uncertainties exist for the pelagic realm because of its higher variability, plus little is known about the meso- and bathypelagic zones. A changing environment and modifications of habitats will probably drive new communities from plankton to fish or top predators. We need based-line studies such as those of CAML, databases like SCAR-MarBIN and tools for integrating all of these observations. Our objective is to understand the biodiversity patterns in the Southern Ocean and how these might change.

The Cenozoic glacial history of East Antarctica is recorded in part by the stratigraphy of the Prydz Bay-Lambert Graben region. The glacigene strata and associated erosion surfaces record at least 10 intervals of glacial advance (with accompanying erosion and sediment compaction), and more than 17 intervals of glacial retreat (enabling open marine deposition in Prydz Bay and the Lambert Graben). The number of glacial advances and retreats is considerably less than would be expected from Milankovitch frequencies due to the incomplete stratigraphic record. Large advances of the Lambert Glacier caused progradation of the continental shelf edge. At times of extreme glacial retreat, marine conditions reached > 450 km inland from the modern ice shelf edge. This review presents a partial reconstruction of Cenozoic glacial extent within Prydz Bay and the Lambert Graben that can be compared to eustatic sea-level records from the southern Australian continental margin.

Legacy product - no abstract available

Recently discovered drift deposits on the Antarctic continental shelf provide access to information on the Holocene palaeoceanography of the bottom current regime within deep shelf basins that were previously inaccessible. The George Vth Basin on the East Antarctic margin has been identified by oceanographers as an important source of Antarctic Bottom Water, hence the Holocene history of bottom current activity here may be relevant to variations in bottom water export.

No abstract available

This abstract contains and overview of the datasets acquired by the Australian Antarctic and Southern Ocean profiling Project in the Antarctic summers of 2000/01 and 2001/02.

This abstract contains a summary of the broad scientific results coming out of the interpretation of data acquired under the Australian Antarctic & Southern Ocean Profiling Project.