Intrusion-related gold-rich systems occur throughout eastern Australia. The last 20 years has seen a large increase in our understanding of the relationships between mineralisation and associated felsic intrusions, in particular, the strong relationship between the oxidation state and degree of compositional evolution of felsic magmas, and potential associated commodity types. This paper reviews recent developments in igneous metallogeny, in particular, with regard to intrusion-related Cu-Au and Au mineralisation, to show that eastern Australia is still prospective for granite-related gold systems. Major potential exists, both under cover and as blind deposits. To aid in discovery, Geoscience Australia is synthesising metallogenic data for both Palaeozoic intrusions of eastern Australia, and local country rock units

Paper presented at the World Diamond Conference held in Perth, 20-21 November, 2006. The paper gives an overview of current diamond exploration and discovery in Australia and reviews the state of knowledge of the geological setting and controls on known diamondiferous intrusions in Australia as an important indicator of Australia's diamond potential. Reduced levels of spending in recent years has been associated with a contraction of exploration largely to brownfields regions. Exceptions are the discovery of the diamondiferous Blacktop kimberlite in the West Pilbara region and, to a lesser extent, new kimberlites discovered in the eastern Gawler Craton. Most Australian kimberlites and lamproites, like those elsewhere, show evidence of strong structural controls. These features are commonly evident in continental scale geophysical datasets. Many of the diamondiferous intrusions lie at major boundaries/discontinuities evident in seismic S-wave tomographic models and at discontinuities evident in multi-scale analysis of horizontal gradients of continental magnetic anomaly and gravity datasets (Jaques and Milligan, 2004: Lithos 77, 783-802). These relationships are predicted by modelling with numerical mantle convection code which indicates that abrupt changes in lithospheric thickness focus lithospheric stress gradients affecting melt migration and accumulation thereby making the mantle beneath the margins of stable cratons favourable sites for kimberlite generation (O'Neill, Moresi and Jaques, Tectonophysics 404, 217-236). Diamond potential is intimately linked to craton evolution. Eclogitic diamond suites appear to be linked to subduction events at craton margins. Continental-scale geophysics can help define fertile source regions (mantle roots) and identify favourable tectonic zones/corridors. Improved targeting is required to better identify greenfields provinces which have the potential to host new diamond pipes. Such targeting would be enhanced by improved seismic tomographic models of the Australian lithosphere and through a better understanding of geodynamic evolution of the Australian continent.

Paper presented at the Association of Mining and Exploration Companies (AMEC) National Mining Congress 2007, 7-8 June 2007, Perth Convention Centre, Western Australia. Ore deposits of Proterozoic age account for more than 90% of Australia's known iron ore, uranium and lead resources, most of Australia's known zinc (84%) and copper (71%) resources, and significant gold (17%) resources. Most of these deposits were formed by mineralising systems in the period 2000-1500 Ma, with the most fertile being the period 1690-1500 Ma. Recent Geoscience Australia regional projects conducted under the National Geoscience Agreement with State and NT partners have brought new understanding to the controls on distribution of these deposits.

This talk summarises the ‘essential ingredients’ considered important for formation of major Olympic Dam-style IOCG systems in the Gawler Craton, and elsewhere. A ‘working model’ of a crustal-scale IOCG system is presented for the Olympic Dam region. Finally, the newly released IOCG Potential Map of the Gawler Craton is described.

The presentation covers the following: - a brief review of GA's Onshore Energy Security Program - U systems and national projects - regional projects and the geophysical acquisition program - input into GA's plans for precompetitive data acquisition

Pending

This paper was presented at the Australian Nickel Conference held in Perth, 18-19 October 2006 . The nickel industry in Australia is currently experiencing a 'boom phase' with spiralling metal prices to record levels (at least US$34,750/tonne), dwindling global stockpiles, and exploration expenditures and activities near all-time highs. To assist nickel explorers, Geoscience Australia has published a new 1:3 500 000 colour map A Synthesis of Australian Proterozoic Mafic-Ultramafic Magmatic Events. Part 1: Western Australia. The map, for the first time, summarises the major known Proterozoic mafic and ultramafic magmatic events and associated mineral deposits in Western Australia. The major objective of this presentation is to promote the applications of this particular map which should be of interest to those involved in the metallogenesis of mafic-ultramafic rocks, or the study of Proterozoic provinces in Western Australia

National Geochemical Survey of Australia field training for the geoscience agencies of all States and the Northern Territory took place during 2007 and early 2008. The knowledge transfer mechanisms comprise a detailed National Geochemical Survey of Australia: Field Manual (GA Record 2007/08), this training presentation and several days of in-field sample collection under the guidance of NGSA staff.

This paper aims to present an overview of mineral exploration highlights and hotspots in Australia for 2007. Presented at the Association of Mining and Exploration Companies National Mining Congress 7-9 June 2007, Perth Convention Centre, Western Australia.

Systems Project is a key part of the $59m Onshore Energy Security Program (OESP) underway at Geoscience Australia (2006-2011). The project has three objectives: (1) develop new understandings of processes and factors that control where and how uranium mineralisation formed, (2) map the distribution of known uranium enrichments and related rocks in Australia, and (3) assess the potential for undiscovered uranium deposits at regional to national scales. Objective (1) has been addressed initially by reviewing current classification schemes for uranium deposits. Most schemes emphasise differences in host rock type and list 15 or more deposit types. An alternative scheme is proposed that links the apparently separate deposit types in a continuum of possible deposit styles. Three end-member uranium mineral systems are: magmatic-, basin-, and metamorphic/metasomatic-related. Most recognised deposit styles can be considered as variants or hybrids of these three end-members. For example, sandstone hosted, unconformity-related and `Westmoreland style deposits are viewed as members of basin-related uranium systems and which share a number of ore-forming processes. Identification of the spatial controls on uranium mineralisation is being investigated using numerical modelling, with the Frome Embayment of SA as a first case study. Mapping the distribution of uranium in objective (2) has commenced with the release of a new map of Australia showing the uranium contents of mainly outcropping igneous rocks, based on compilation of whole rock geochemical data. A clearer picture of uranium enrichments is also emerging through cataloguing of an additional >300 uranium occurrences in the MINLOC mineral occurrence database. Finally, the recently completed Australia-wide radiometric tie-line survey is providing a new continent-scale view of uranium, thorium and potassium distributions in surface materials.