Deep crustal seismic data collected in 2006 and 2007 highlight prospectivity for geothermal and energy mineral systems in north Queensland as well as providing insight into geodynamic controls on IOCG(U) and metasomatic U deposits. IOCG deposits in the eastern Mt Isa Inlier are located in the hanging wall of a major crustal discontinuity that is imaged at surface as a gravity high. At a broader scale these deposits are spatially associated with the Carpentaria conductance anomaly, which can be traced south to the Olympic IOCG(U) deposit. The surveys also identified the previously unknown Millungera Basin which appears to overlie granitic bodies. This architecture is favourable for the presence of geothermal systems, with the granites providing heat beneath the basin insulator and heat trap. This basin has unknown potential for petroleum and energy minerals. Metasomatic deposits in the western Mt Isa Inlier appear to be associated with inverted extensional faults that bound major troughs. Inversion of these faults during the Isan Orogeny allowed fluid flow to suitable U traps.

Rare-earth elements (REE: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium) have unique chemical, magnetic, and luminescent properties that make them critical to several high-technology industries. Their applications in many emerging technologies associated with the transport, information, environment, energy, defence, nuclear, and aerospace industries have gained rapid momentum in recent years. This, together with a narrow global supply base, has led to price increases for the REE, and so they are becoming an increasingly attractive commodity for the mineral industry. This report describes the distribution, geological characteristics, and resources of Australia's major REE deposits as a stimulus for further research into their geological characteristics. The information and main messages presented are intended to inform the public, students, and professionals.

No abstract available

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.

The Northern Territory is an integral part of the great Australian Pre-Cambrian shield which underlies almost the whole of Western Australia and the Northern Territory, much of South Australia and portions of New South Wales and Queensland. In most parts of the Continent, Pre-Cambrian rocks were welded into a stable shield before the end of Pre-Cambrian time, and in the Northern Territory itself the structural framework was established, and most of the mineral deposits introduced by an orogeny which terminated geosynclinal sedimentation about the end of the Lower Proterozoic. This discussion of the structure of the Territory in relation to mineralization is mainly concerned with Pre-Cambrian, and in particular with Lower Proterozoic rocks. Only a broad outline of the subject is given here.

Mineralizing events in the North Pilbara Terrain of Western Australia occurred between 3490 Ma and 2700 Ma and include the oldest examples in the world of many ore deposit types. The mineralizing events were pulsed and associated with major volcano-plutonic (volcanic-hosted massive sulfide [VHMS], porphyry Cu, Sn-Ta pegmatite, mafic-ultramafic-hosted Ni-Cu-PGE, Cr and V, and epithermal deposits) and deformation events (lode Au?Sb deposits). In many cases, the mineralizing events are associated with extension, either in rifts, pull-apart basins or back-arc basins. Although mineralizing events occurred throughout the evolution of the North Pilbara Terrain, the most significant deposits are related to the development of the Central Pilbara Tectonic Zone (CPTZ). The CPTZ is sandwiched between the older East and West Pilbara Granite-Greenstone Terranes. Four significant volcano-plutonic and three significant deformation events occurred in and around the CPTZ between 2950 and 2840 Ma, a relatively short period in the evolution of the North Pilbara Terrain. Mineralization in the East and West Pilbara Granite-Greenstone Terranes was less intense and occurred over a much longer period. Compared to other Archean granite-greenstone terranes, the North Pilbara Terrain is poorly endowed: the only known world-class deposit in this region is the Wodgina Ta-Sn deposit. This lack of major mineral deposits may relate to the low rate of crustal growth of the North Pilbara Terrain. If such is the case, then the long history of crustal development and extensive recycling in the Pilbara is responsible for both the diversity of mineral deposits therein and, partly, the apparent poor endowment of the North Pilbara Terrain.

No abstract available

Zn-Pb-Ag mineral deposits, which are the products of specific types of hydrothermal "mineral systems", are restricted in time and space in Australia. These deposits formed during three main periods: ~2.95 Ga, 1.69-1.58 Ga, and 0.50-0.35 Ga. The 1.69-1.58 Ga event, which was triggered by accretionary and rifting events along the southern margin of Rodinia, is by far the most significant, accounting for over 65% of Australia's Zn. With the exception of the 0.50-0.35 Ga event, major Australian Zn-Pb-Ag events do not correspond to major events globally. Over 95% of Australia's Zn-Pb-Ag resources were produced by just four mineral system types: Mt Isa-type (MIT: 56% of Zn), Broken Hill-type (BHT: 19%), volcanic-hosted massive sulfide (VHMS:12%), and Mississippi Valley-type (MVT: 8%). Moreover, just 4% of Australia's land mass produced over 80% of its Zn. The four main types of mineral systems can be divided into two groups, based on fluid composition, temperature and redox state. BHT and VHMS deposits formed from higher temperature (>200?C), reduced fluids, whereas MIT and MVT deposits formed from low temperature (<200?C), oxidized (H2S-poor) fluids. These fluid compositions and, therefore, the mineralization style are determined by the tectonic setting and composition of the basins that host the mineral systems. Basins that produce higher temperature fluids form in active tectonic environments, generally rifts, where active magmatism (both mafic and felsic) produces high heat flow that drives convective fluid circulation. These basins are dominated by immature siliciclastic and volcanic rocks with a high overall abundance of Fe2+. The high temperature of the convective fluids combined with the abundance of Fe2+ in the basin allows sulfate reduction, producing reduced, H2S-rich fluids. In contrast, basins that produce low temperature fluids are tectonically less active, generally intracratonic, extensional basins dominated by carbonated and mature siliciclastics with a relatively low abundance of Fe2+. Volcanic units, if present, occur in the basal parts of the basins. Because these have relatively low heat flows, convective fluid flow is less important, and fluid migration is dominated by expulsion of basinal brines in response to local and/or out-of-area tectonic events. Low temperatures and the lack of Fe2+ prevent inorganic sulfate reduction during regional fluid flow, producing oxidized fluids that are H2S-poor. The contrasting fluid types require different depositional mechanisms and traps to accumulate metals. The higher temperature, reduced VHMS and BHT fluids deposit meatls as a consequence of mixing with cold sewater. Mineralization occurs at or near the seafloor, with trapping efficiencies enhanced by sub-surface replacement or deposition in a brine pool. In contrast, the low temperature, oxidized MIT and MVT fluids precipitate metals through thermochemical sulfate reduction facilitated by hydrocarbons or organic matter. This process can occur at depth in the rock pile, for instance in failed petroeum traps, or just below the seafloor in pyritic, organic-rich muds. Mass balance calculations indicate that the size of a metal accumulation, although controlled at the first order by the mineral system container size, also depends on the efficiencies at which metals are extracted from the source and retained at the trap site. The shear size of minerals systems required to form giant deposits may partly explain why these deposits commonly occur by themselves, without significant satellite deposits. In addition to the size of the mineral system container, metal retention efficiency appears to be the most important determinant of the size of metal accumulations.

As part of the Australian Government's Onshore Energy Security Program and the Queensland Government's Smart Mining and Smart Exploration initiatives, deep seismic reflection surveys were conducted in North Queensland to establish the architecture and geodynamic framework of this area in 2006 (Mt Isa Survey; also involving OZ Minerals and pmd*CRC) and 2007 (Cloncurry-Georgetown-Charters Towers Survey; also involving AuScope). Nearly 2300 line km of seismic data were acquired during these surveys. Geochemical, geochronological and complementary geophysical studies were undertaken in support of the seismic acquisition. Overviews of the geology of North Queensland and more detailed descriptions and the results of these surveys are presented in Hutton et al. (2009a, b), Korsch et al. (2009a), Withnall et al. (2009a, b), Henderson and Withnall (2009), and Henderson et al. (2009). The purpose here is to use the new geodynamic insights inferred from these data to provide comments on the large-scale geodynamic controls on energy and other mineral potential in North Queensland. This contribution draws on geodynamic and metallogenic overviews presented by Korsch et al. (2009b) and Huston et al. (2009)

Presentations from 'THE ISHIHARA SYMPOSIUM' held at GEMOC, MACQUARIE UNIVERSITY, JULY 22-24 2003; on a variety of topics ranging from general granite processes to mineralisation associated with magmatism.