ACRES Update, Issue 25, December 2001 Government widens access to spatial data STAR Service in agricultural industry Australian landcover as never seen before

ACRES Update, Issue 24, July 2001 STAR Service shortens delivery time ACRES Poster features impace crater A unique applicaiton using satellie imagery as art

Titles in this newsletter: Gold mineral systems in the Tanami region: New insights from NTGS-AGSO research A mineralssystems approach to mapping Australia's endowment Sources of organic matter in Wallis Lake Publications involving AGSO authors: December 2000 to April 2001 North Pilbara National Geoscience Mapping Accord project (1995-2000): Scientific highlights Metallogenic potential of mafic-ultramafic intrusions in the Arunta Province, central Australia: Some new insights Rapid mapping of soils and salt stores: Using airborne radiometrics and digital elevation models

Nara Inlet in the Whitsunday Islands is a natural depocenter for clastic and carbonate sediment on the middle shelf of the central Great Barrier Reef (GBR) platform. Three sediment cores were collected from the inlet to understand sediment accumulation in this tropical mixed clastic/carbonate system over time. Surface and subsurface sediment is comprised of two main components: terrigenous clay and shallow marine carbonate. Similar to other regions on the middle shelf of the GBR platform, the carbonate component, 25.80% by weight and dominated by Sr-poor foraminifera tests and mollusc shells, generally increases towards the surface. Radiocarbon ages derived from tests of benthic foraminifera indicate that the top 3 m of sediment accumulated within the last 3000 years, but that the rate has slowed toward present-day. The change in clastic and carbonate abundance therefore indicates a system where both clastic and carbonate accumulation has decreased over time, but where clastic accumulation has decreased faster. Reduced clastic accumulation may reflect progressive impedance of terrigenous input by a laterally growing fringing reef at the mouth of Nara Inlet. Likewise, reduced carbonate accumulation may reflect preferential reef growth and carbonate deposition outside of the inlet. Even though clastic accumulation has decreased significantly over time, the late Holocene mass, composition, and distribution of clastic material in Nara Inlet implies a terrigenous source previously unrecognized in models for the evolution of the GBR platform. Large amounts of terrigenous sediment probably were stored around topographic highs on the middle shelf during lowstand and early transgression. This clastic material was then removed over time, mixed with autochthonous carbonate, and deposited in embayments on the middle shelf. The accumulation of sediment on the middle shelf of a tropical mixed clastic/carbonate margin is not straightforward.

The Prince Charles Mountains constitute by far the best-exposed cross section through the East Antarctic Shield, extending for over 500 kilometers along the drainage basin of the Lambert Glacier-Amery Ice Shelf system. They consist of three distinct geological terranes: the Archaean to 'Mesoproterozoic Ruker Terrane in the south and the Mesoproterozoic to early Neoproterozoic Fisher and Beaver-Lambert Terranes in the north.

In early 2000 the Australian Geological Survey Organisation (AGSO) completed two major seabed swath-mapping and geophysical surveys of the Australian South-east Marine Region. These surveys, AUSTREA-1 and AUSTREA-2, were commissioned by the National Oceans Office and Environment Australia and were designed to provide important new scientific information on the seabed in this region to assist implementation of Australia's Ocean Policy, and in particular, development of the South-east Regional Marine Plan and establishment of marine protected areas (MPAs) within and adjacent to the South-east Marine Region.

Australian estuaries and coastal waterways were classified into six subclasses according to the wave-, tide- and river-energies that shape them, and also according to their overall geomorphology. The geomorphic classification confirmed the energy classification. Within this framework: - 17% were classified as wave-dominated estuaries; - 11% were classified as tide-dominated estuaries; - 10% were classified as wave-dominated deltas; and - 9% were classified as tide-dominated deltas Therefore, only ~28% of Australian coastal waterways are actually estuaries. The remainder are delta's (19%), strandplains (~5%), or tidal creeks (~35%). A seventh subclass others (13%) includes: Drowned River Valleys, Embayments and Coastal Lakes/Lagoons/Creeks. Strandplains and Tidal Creeks are indicative of very low river-energy, and their joint dominance in the data set (~40%) reflects the fact that Australia is a dry continent, with relatively little river runoff by world standards.

Abstract volume of Eastern Lachlan Orogen workshop 7-9 March 2001

The report summarises earthquake and tsunami information worldwide in 1997 but with a focus on Australia for use by scientists, engineers and the public. Maps of the seismicity are presented on a state-by-state basis and isoseismal maps are included for the significant earthquakes.

This paper describes the highlights of AGSO's work in the North Pilbara Project, a joint AGSO-Western Australia Geological Survey (GSWA) effort conducted under the National Geoscience Mapping Accord (NGMA) between 1995 and 2000. One of the principal drivers for AGSO's research in the Pilbara was the possible inapplicability of exploration models and genetic interpretations of Archaean mineral deposits because these models were commonly based upon late Archaean examples. One of our goals was to document the differences between the late Archaean and the early-mid Archaean mineral systems, and to develop regional thematic synthesis datasets so that more robust models could be developed to encompass the entire Archaean era. These datasets, together with our research into new exploration tools, have, and continue to assist exploration in the Pilbara. Our results also have applications to other terranes.