The Yilgarn Craton of Western Australia is an Archaean nucleus surrounded by Proterozoic orogenic belts that include the Capricorn belt to the north, the Albany-Fraser Orogen to the east and Wilkes Land in Antarctica. The Yilgarn Craton itself preserves large-scale geodynamic signatures within the crust and mantle that reflect its tectonic and metallogenic evolution. Integration of geophysical datasets such as broad-band tomographic images of the lithosphere, receiver function velocity profiles of the crust, seismic reflection deduced crustal architectures, together with geology, geochemical and geochronological datasets has provided insights into the processes of formation of the craton at the largest scales and within the three-dimensional architecture of the region at the time the mineral system were operating.

<p>Geomagnetic and meteorological observations of the Antarctic 1898-1900 in 2 parts. <p>Part 1: Magnetic observations taken by Louis Bernacchi and W. Colbeck, reduced by Charles Chree with the assistance of Louis Bernacchi; <p>Part 2: Meteorological observations taken by the staff of the "Southern Cross" including Herlof Klovstad, Nicolas Hanson, H. Evans, A. Tongner, L. Bernacchi and W. Colbeck reduced under the superintendence of W.N. Shaw with an introduction and notes by L. Bernacchi.

The 2000-2001 Antarctic Geodesy Summer Program consisted of a number of distinct components including - ARGN reference mark surveys and Orthometric height connections at Mawson and Davis. This report details the work completed in the 2000-2001 summer season, by AUSLIG (now Geoscience Australia) geodetic surveyors between November 2000 and March 2001.

The main objectives of the 2000 geodetic survey of Heard Island were to upgrade and extend the existing geodetic survey network to give a better coverage of the island and to establish accurate, globally compatible coordinates for all spatial data applications on the Island. In addition, GPS observations would provide information for the long-term measurement of horizontal and vertical movement. In the long term, these fundamental positions will provide information on the contemporary motion of Heard Island for comparison with geological records, with special emphasis on the Australia-Antarctic separation and the mid ocean ridge. In the meantime they provide a consistent and globally compatible spatial framework for all other studies on the Island. This report documents the methods and results of these surveys.

This is an online GIS application of Antarctica

Two sediment cores collected from beneath the Amery Ice Shelf, East Antarctica describe the physical sedimentation patterns beneath an existing major embayed ice shelf. The latest core, AM01b, was collected from a site of basal freezing, contrasting with the previous core AM02, collected from a site of basal melting. Both cores comprise Holocene siliceous muddy ooze (SMO) however AM01b recovered interbedded siliciclastic mud, sand and gravel with inclined bedding in its lower 27 cm. This interval indicates an episode of variable but strong current activity before SMO sedimentation became dominant. 14C ages corrected for old surface ages are consistent with previous dating of marine sediments in Prydz Bay however the basal age of the AM01b core of 28250 +/- 230 14C yr BP probably results from greater contamination by recycled organic matter. Lithology, 14C surface ages, absolute diatom abundance, and the diatom assemblage are used as indicators of sediment transport pathways beneath the ice shelf. The transport pathways suggested from these indicators do not correspond to previous models of the basal melt/freeze pattern. This indicates that the overturning baroclinic circulation beneath the Amery Ice Shelf (near-bed inflow - surface outflow) is a more important influence on basal melt/freeze and sediment distributions than the barotropic circulation that produces inflow in the east and outflow in the west of the ice front. Localised topographic (ice draft and bed elevation) variations are likely to play a dominant role in the resulting sub-ice-shelf melt and sediment distribution. The inflow of marine sediments in the Holocene section of AM01b, as shown by the abundance of marine diatoms and other planktonic organisms, supports a diverse filter feeder community beneath the ice shelf through the supply of suspended organic matter and oxygen.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

Hemipelagic, sediment drift deposits have been discovered and mapped on the Antarctic Peninsula shelf in 300-500 m water depth. The drift located adjacent to Andvord Bay covers 44.5 km2 and exhibits continuous and discontinuous parallel reflections that conform to peaks and valleys in the acoustic basement as observed in deep-tow boomer and sparker seismic records. This style of drift deposit is a common feature of deep oceanic sediments, but is not normally found in continental shelf environments.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

The Stillwell Hills region comprises granulite facies gneisses which record evidence for multiple periods of deformation and metamorphism spanning more than 2500 Million years. The predominant orthogneiss package (Stillwell Orthogneiss) represents the margin of an Archaean craton exposed in Enderby Land, some 150 km to the west that was reworked during the late Proterozoic. Younger additions to the crust include Palaeoproterozoic charnockitic gneiss (Scoresby Charnockite) and Meso-Neoproterozoic mafic sills and dykes (Point Noble Gneiss, Kemp Dykes) and felsic pegmatites (Cosgrove Pegmatites). Subordinate supracrustal rocks, including metaquartzite, metapelitic, metapsammitic and calc-silicate gneiss (Dovers Paragneiss, Sperring Paragneiss, Stefansson Paragneiss, Keel Layered Paragneiss, Ives Gneiss) are intercalated and interfolded with the Archaean-Palaeoproterozoic orthogneisses.