This address was presented at the 2008 Australian Nickel Conference held in Perth, 22-23 October 2008. Geoscience Australia has released a detailed, web-based colour map (at 1:5 000 000 and 1:10 000 000 scales) 'Australian Proterozoic Mafic-Ultramafic Magmatic Events (Sheets 1 and 2)'. This new map is the third and final component of the Proterozoic magmatic event series that show, for the first time, the geographic extent and age relationships of Proterozoic mafic and ultramafic rocks, and associated mineral deposits throughout the continent. The maps (`Proterozoic mafic-ultramafic magmatic events of Western Australia' and 'A Synthesis of Australian Proterozoic Mafic-Ultramafic Magmatic Events. Part 2: Northern Territory and South Australia') were produced in close collaboration with the State and Northern Territory geological surveys.

Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. Over a half (570) of the known uranium occurrences in Australia are located in the North Australian Craton and the overlying Ngalia, Amadeus, and McArthur River basins. These occurrences include 43 uranium deposits with recorded resources. The uranium occurrences and deposits show a general spatial relationship to uranium-enriched felsic igneous rocks. The total uranium resource (production + resources) of the North Australian Craton and the overlying basins amount to about 510,000 t U3O8. The bulk of these resources are accounted for by the following: unconformity type in the Pine Creek Orogen (~420,000 t U3O8), sandstone uranium (~36,000 t U3O8) in the McArthur, Amadeus and Ngalia Basins, metasomatite (~38,000 t U3O8) and metamorphic deposits of the Mt Isa Orogen, and calcrete deposits in Arunta. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The Tanami Region (TANAMI and THE GRANITES 1:250 000 map sheet areas) is centrally located within the North Australian Craton and contains a gold-mineralised Palaeoproterozoic orogenic sequence. Page et al (1995) postulated Neo-Archaean granitic gneiss as basement to the Tanami Group, although no lower sedimentary contact has been observed. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The Pine Creek Orogen (PCO) is part of the North Australian Craton and is correlated with other Palaeoproterozoic domains of northern Australia. Archaean (>2.5 Ga - 2.7 Ga) granite and metamorphics are overlain by Palaeoproterozoic strata comprising sandstone, mudstone, and minor carbonates and volcanics. Its age is constrained between 2.5 Ga and 1.86 Ga, and the succession is divided into two supergroups. The older Woodcutters Supergroup comprises <2.5 Ga to 2.02 Ga arenites, stromatolitic dolostone, and pyritic carbonaceous shale. The younger Cosmo Supergroup comprises BIF, mudstone, and tuff, succeeded by a monotonous flysch sequence. Zircons from the tuff beds provided an age of 1863 Ma, confirming a major depositional break of about 150 million years. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The 2005 Tanami Seismic Collaborative Research Project produced four regional deep seismic reflection traverses, 05GA-T1 through 05GA-T4, totalling 724 line-km. Traverse 05GA-T1, a 354.3 km long northwest-southeast regional transect started in Western Australia and ended in the Northern Territory. It was located close to Tanami Gold's Bald Hills deposits and Newmont's Tanami and The Granites mine sites. This traverse provided cross-strike information on the geometry of the Coomarie and Frankania granite complexes as well as many of the region's fault systems. The traverse ended at the southern edge of the Willowra Gravity Ridge. The cross-traverses, 05GA-T2 (101.8 km long), 05GA-T3 (179.2 km long) and 05GA-T4 (84.4 km long) provide orthogonal three-dimensional control on the geometry of the region's main fault systems. The project objectives are to: - Image the geometry of the main faults; - Determine a deformation sequence for these faults; - Identify any through-going crustal structures; - Determine stratigraphic thicknesses of the Tanami Group and granite body geometries; - Determine relationships of the various stratigraphic packages to controlling structures; - Investigate the relationship of mineralised domains to crustal scale structures; - Identify Archaean basement and its relationship to the overlying Tanami Group stratigraphy; - Investigate the character of the Tanami-Arunta boundary. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

The Ranger deposit is one of Australia's largest known uranium resources, with current open pit mining of the No. 3 orebody and a total resource of 109,600 tonnes of U3O8 grading 0.08% at this orebody (ERA, January 2011). This unconformity-related deposit is hosted by Paleoproterozoic metasedimentary rocks of the Cahill Formation which is unconformably overlain by sandstones of the Kombolgie Formation. A maximum depositional age of ~1818 Ma is inferred for the sandstones, based on the presence of the Nabarlek Granite of this age in the basement beneath the Kombolgie Formation. Most mineralisation occurs within a largely stratabound shear and breccia zone and is associated with intense proximal chlorite and distal white mica alteration. The Kombolgie Formation is weakly deformed, faulted and weakly chloritised above the mineralisation.

Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The North Australian Craton (NAC; Myers et al. 1996) includes Palaeoproterozoic orogens and basins in northern Australia including the Halls Creek, Pine Creek, McArthur, Mount Isa, Tennant Creek, Tanami, and Aileron (northern Arunta) geological regions. Archean basement to the NAC crops out in the Pine Creek and Tanami regions, with ages in the range 2.67 Ga - 2.50 Ga. An early phase of basin development at 2.05-2.00 Ga is reflected in the basal units of the Pine Creek Orogen. The nature of the basement remains unclear across much of the NAC, although geophysical and isotopic evidence suggests widespread presence of thick Neoarchean to Palaeoproterozoic continental crust. Recent work by the Northern Territory Geological Survey and Geoscience Australia , particularly the Arunta and Tanami Regions, has provided important new constraints on the tectonic evolution of the North Australian Craton. Current evidence suggest that most of the NAC was a coherent entity by 1.86-1.83 Ga, when large areas of the craton was covered by thick sedimentary packages which now form regionally important hosts for gold mineralisation. In the Northern Territory, apparent correlations are now possible between packages at 1.865-1.860 Ga (Finniss River and South Alligator Groups, Waramunga Formation, Junalki Formation), 1.84-1.83 Ga (Lander Rock Formation, Killi Killi Formation, lower Ooradidgee Group), and 1.82-1.80 Ga (Ware Group, Hatches Creek Group, Strangways Metamorphic Complex). Tectonism throughout much of the Northern Territory in this period was dominated by intraplate tectonics, although these are likely to have been driven by events at the northern and western margins of the craton, such as the postulated collision between the Kimberley and North Australian Cratons at 1.83 Ga (Sheppard et al. 1999). <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

As part of the North Pilbara NGMA Project, AGSO (now Geoscience Australia), together with Newcastle University and the Geological Survey of Western Australia (GSWA), have been conducting a research program to document the geological setting, characteristics and genesis of Au deposits of the North Pilbara Terrane. This record summarises some results of this research program. This research has concentrated on turbidite-hosted lode Au deposits in the Indee and Nullagine areas as well as basalt and ultramafic-hosted deposits in the Mt York-Lynas Find area. In addition to these areas, AGSO's research also concentrated on epithermal deposits in the Indee area, and less detailed studies were undertaken on lode Au deposits at Gold Show Hill and Klondyke. This research program was designed to complement recent (e.g., Neumayr et al. [1993; 1998] on the York deposits and Zegers [1996] on the Bamboo Creek deposits) and ongoing (e.g., D. Baker, University of Newcastle] at Mt York-Lynas Find) programs conducted at the other institutions. This Pilbara Gold Record is supported by an extensive GIS dataset, providing many new digital data sets, including a number of variations of the magnetics, gravity, and gamma-ray spectrometry. A solid geology map, and derivative maps, mineral deposits, geological events, and Landsat 5-TM provide additional views. This data set complements the 1:1.5 Million scale colour atlas (Blewett et al., 2000).

The Moonta Domain forms the southern part of the Olympic Cu-Au province on the eastern margin of the Gawler Craton. Historical production comprises over 330,000 tonnes of Cu from vein and shear-hosted mineralisation in the Moonta-Wallaroo district. The domain basement comprises metasediments and metavolcanics of the Palaeoproterozoic Wallaroo Group (~1760?1740 Ma) which were deformed and metamorphosed to upper greenschist-amphibolite facies during the Kimban Orogeny (~1720 Ma). These rocks were further deformed and intruded by granitoids and minor mafic intrusions of the Hiltaba Suite between about 1600 Ma and 1575 Ma. There is a close spatial association of high temperature Fe-Na-Ca-K metasomatism of the Wallaroo Group and Hiltaba Suite intrusions. Conor (1995) termed the most strongly altered rocks the Oorlano Metasomatites, although metasomatic mineral assemblages within this rock association vary widely. Intense albite-actinolite-magnetite ? carbonate ? epidote ? pyrite alteration of metasediments is strongly associated with the contact zones of Hiltaba Suite granites, particularly the Tickera Granite. More distal albitisation of the Wallaroo Group is common but is not generally associated with significant sulphides. Biotite ? albite ? magnetite ? quartz ? apatite ? monazite ? tourmaline alteration is commonly associated with pyrite ? minor chalcopyrite, and is particularly widespread south of Moonta where numerous magnetic and non-magnetic Hiltaba Suite granitoids (previously grouped as Arthurton Granite) intrude the Wallaroo Group. Late chlorite and K-feldspar alteration is typically of restricted extent, but may also be associated with sulphides. Biotite-rich alteration typically forms irregular magnetic anomalies, including a major 5 x 15 km alteration zone near Weetulta, and possibly a large area (~30 km x 40 km) of strongly magnetic rock beneath Spencer Gulf. Fluid inclusion data indicate that highly saline, multi-cation fluids are associated with the alteration. Preliminary U?Pb SHRIMP dating of hydrothermal monazite from biotite-rich alteration in the Weetulta and Wallaroo areas yields ages of approximately 1585 Ma and 1620 Ma respectively. The Weetulta district data indicate a close temporal relationship of the biotite alteration and Hiltaba Suite magmatism. However, the older Wallaroo district age suggests hydrothermal activity may have commenced prior to intrusion of Hiltaba Suite granites. Regional metamorphic and alteration characteristics of the Moonta Domain are similar to those of the Fe-Cu-Au mineral province of the Mt Isa Inlier Eastern Succession, where there are strong links between magmatism, regional albitisation, and Fe-Cu-Au mineralisation (eg., Oliver et al., 2001). Biotite-magnetite metasomatism commonly occurs proximal to major Fe-Cu-Au ore deposits in the Mt Isa Eastern Succession. The shear-hosted Cu lodes and associated alteration at Wallaroo may be an analogue in the Moonta Domain. However, apart from some very minor drill intersections in prospects in the Weetulta district, no other significant Cu-Au mineralisation associated with biotite-magnetite alteration has yet been discovered in the Moonta Domain. Given that most of the Proterozoic basement of the Moonta Domain is concealed by up to 100 metres of Neoproterozoic to Cainozoic sediments and remains largely untested by drilling, the potential for discovery of Ernest Henry-style Fe-Cu-Au deposits in the Moonta Domain remains high.

Australia holds the world's largest resources of uranium recoverable at low cost, principally in the uranium-rich Olympic Dam iron oxide Cu-Au (IOCG) deposit together with the Ranger and Jabiluka unconformity-related deposits and Yeelirrie surface-related deposit. Despite this impressive inventory, resources of several other styles of uranium deposits appear to be under-represented in Australia relative to geologically similar regions elsewhere in the world. In particular, Australia has no known giant uranium deposits hosted by Mesozoic or younger sedimentary basins, although recent discoveries in the Frome Embayment have significantly increased total resources of `sandstone' uranium in the region. Major deposits directly related to magmatic processes also appear to be under-represented, given the abundance of unusually uranium-rich igneous rocks in Australia. The Australian Government's Onshore Energy Security Program (OESP 2006-2011) is providing pre-competitive geoscientific data and new area selection concepts to assist in reducing exploration risk and to support an assessment of onshore energy and uranium potential. This report examines the key processes controlling where and how uranium mineralisation occurs in Australia and elsewhere. Based on this process understanding and on descriptions of well-documented systems, we develop generalised models of three distinct families of uranium mineral systems, including exploration criteria. The purpose of the report is to present a revised framework for a fresh assessment of Australia's uranium mineral potential. This systems-based approach, when combined with empirical data, provides a means of identifying previously unrecognised uranium provinces or districts. The report has three parts. First, the fundamental chemical controls on uranium transport and deposition in aqueous geological systems are reviewed. Second, a new scheme of classification of uranium deposits is proposed (see below). Third, each of three families of uranium mineral systems, plus hybrid systems, is described in terms of ore-forming processes, essential components of the mineral system, and mappable criteria. Exploration models for key systems are presented in figures and tables.