The North Pilbara Terrane has the largest variety of mineral deposits of any Archaean province. It contains the oldest known examples of volcanic-hosted massive sulphide (VHMS), lode Au, porphyry Cu, orthomagmatic Ni-Cu-PGE-V, pegmatitic Ta-Sn and epithermal deposits, with a diversity more characteristic of Phanerozoic mobile belts. Despite this diversity the North Pilbara Terrane appears to lack any major mineral deposits, with the exception of the Wodgina Ta-Sn pegmatite field. Below, we present the metallogenic history of the North Pilbara Terrane in the context of its tectonic development and then compare it to other Archaean provinces to assess controls on metal endowment.

Considerable exploration interest has been generated by the platinum-group-element (PGE) and Ni-Cu potential of the Archean layered mafic-ultramafic intrusions in the west Pilbara Craton, Western Australia. The Munni Munni Intrusion contains the largest known resource of PGEs associated with a layered intrusion in Australia, and the Radio Hill and Mount Sholl intrusions host significant resources of Ni-Cu-Co sulfides. Titaniferous magnetite layers, remobilized sulfides, and structurally controlled hydrothermal polymetallic deposits have also been a focus for exploration in recent years. The ca. 2.9 Ga Munni Munni, Andover, Radio Hill, Mount Sholl, and Sherlock layered intrusions are a cogenetic suite of high-level (<5 kb) bodies that represent some of the oldest mineralizing systems of their type in the world. Although they display similar field relationships and mineralogical, geochemical, and isotopic features, their contrasting chalcophile metal distribution patterns show that the timing and mechanism of the S-saturation event were critical for the development of PGE-enriched sulfide-bearing layers and basal segregations of base-metal sulfides. The intrusions form thick (>5.5 km) 'dike'-like bodies or relatively thin (0.5-2 km) sheets and sills emplaced at different levels along major lithological discontinuities in the upper crust. Rhythmically layered ultramafic components are generally thinner than, and occur along the northern sides of, more massive overlying mafic components. The ultramafic zones consist of dunite, lherzolite, wehrlite, olivine websterite, clinopyroxenite, and websterite. Inverted pigeonite gabbronorite, magnetite gabbro, olivine gabbro, anorthositic gabbro, and anorthosite comprise the mafic sequences. Olivine and clinopyroxene were generally the first minerals to crystallize, except in the Andover Intrusion, where orthopyroxene preceded clinopyroxene and possibly reflects greater contamination of the parent magma by felsic crustal material. The crystallization of chromite was inhibited in the ultramafic zones by the partitioning of Cr into early crystallizing clinopyroxene, thus downgrading the potential for PGE-chromite associations. The PGE mineralization in the Munni Munni Intrusion occurs in the upper levels of a porphyritic plagioclase websterite orthocumulate layer directly below the ultramafic-gabbroic zone contact. Mineral compositional trends and Nd isotopic data indicate that a Pd-Pt-Au-enriched S-undersaturated magnesian basaltic magma was frequently injected into a small magma chamber during formation of the ultramafic zone. A major influx of more fractionated, S-saturated tholeiitic gabbroic magma related to the resident magnesian magma, rapidly inflated the chamber and induced turbulent magma mixing that resulted in the formation of the PGE-bearing porphyritic websterite layer. In contrast, the parent magmas that formed the Mount Sholl, Radio Hill, Andover, and Maitland intrusions were saturated in S before they were emplaced into the magma chambers. In these intrusions gravitational and structural controls were important for the concentration of PGE-poor (5-400 ppb Pt + Pd + Au) massive sulfides in depressions and structural embayments along the basal contacts beneath the thickest sequences of mafic-ultramafic cumulates. The parent magmas to the west Pilbara intrusions were siliceous high-Mg basalts of Al-depleted komatiitic affinity (Barberton-type) with 9-12% MgO, 15-25 ppm Sc, 12-18 ppm Y, low Al2O3/TiO2 (ca. 11, or half chondrite ratios), and light-rare earth enrichment (chondrite-normalized La/Sm = 2.7, La/Lu = 9.0). They were generated with garnet in the residual asthenospheric mantle with probable involvement of a pre-3.0 Ga subduction-modified lithospheric mantle. Isotopic and geochemical modelling suggests that the magmas were contaminated by ca. 3.0-3.3 Ga Archean tonalitic to granodioritic crust before being emplaced into high-level magma chambers.

No abstract available

Cenozoic basins of the Lake Frome region in South Australia contain most of Australia's known resources of sandstone-hosted uranium mineralisation. In addition to the currently operating Beverley uranium mine, two other deposits have been approved for mining (Honeymoon, Four Mile East) and discoveries continue to be made in the region (e.g., Beverley North; Heathgate Resources, announcement September 2009). While the known resources are significant, the potential of the region for very large uranium deposits has not been well understood, in part because of limited knowledge of the regional and district scale geological controls on uranium mineralisation. The multidisciplinary study reported herein applies a 'mineral systems' approach to identify and map the principal geological controls on the location of known uranium mineralisation in the Lake Frome region. This new framework is aimed at providing a basis for refined exploration targeting of areas with potential for major undiscovered deposits, thus reducing investment risk for the exploration industry. There are two resources available. 1. GA Record 2009/040 PDF format 2. GA Record 2009/040 Resource Pack ZIP File (Includes GA Record 2009/040, Figure 3.3, Figure 3.4, Figure 3.5, Figure 3.6, Figure 3.7)

Most of the rocks of the Eastern Succession of the Mt Isa inlier described in this report were formed between 1760 and 1500 Ma, post-dating the Archaean and early Palaeoproterozoic history. The geodynamic settings of both the depositional and orogenic parts of this history have been extensively debated in the past and are still unresolved at present. Progress has been made in this report through an examination of the isotopic signatures of crustal blocks comprising the basement to the cover sequences, by analysing the geodynamic implications of mafic rocks and the voluminous late-orogenic felsic magmatism, and by a more detailed examination of the tectonothermal evolution.

Western Victoria is host to several world class sediment-hosted gold deposits (e.g. Stawell, Ballarat, Bendigo) that have been studied on an individual basis, generally without reference to a well-constrained regional structural and stratigraphic framework. The configuration and availability of fluid conduits (shear zones or other structural settings and appropriate host lithologies) over time is clearly an important factor in the formation of these mineral deposits but the distribution and profiles of fluid pathways with increasing crustal depth are often imprecisely known. It is also probable that the mineralising fluids were not locally sourced, but travelled long distances from their point of origin, making it imperative that all potential fluid conduits be mapped in 3D so that any sub-surface linkages or networks of fluid pathways be identified. These pathways then need to be incorporated into the 3D regional framework so that the key conduits and structures can be further investigated to establish their precise role in either controlling or sustaining fluid flow over geological time scales appropriate for the formation of a major ore-body. The Stawell Zone in western Victoria is ideally placed for such a case study because it contains sequences that relate to the mineralisation types found in Tasmania and those identified in central Victoria and NSW.

The Western Tharsis deposit, located in the Cambrian Mount Read Volcanic Belt of western Tasmania, is one of 22 mainly Cu-Au deposits in the Mount Lyell district. Although Western Tharsis is characterized mainly by disseminated pyrite-chalcopyrite like most other deposits in the Mount Lyell district, it also contains bornite-rich ores characteristic of a second, less common type of deposit in the Mount Lyell district. The deposit is stratabound and occurs within intermediate and felsic volcanic rocks belonging to the Central Volcanic Complex. Alteration is developed symmetrically around the ore zone, with an ore-bearing core characterized by a quartz-chlorite?sericite assemblage. The core is enveloped by a pyritic quartz-pyrophyllite?topaz?fluorite?zunyite?woodhouseite "advanced argillic" assemblage with local bornite-bearing ore zones. This zone, in turn, is enveloped by a pyritic quartz-sericite assemblage and then by an outermost quartz-chlorite-carbonate-sericite?albite assemblage that lacks pyrite. The bornite-related pyrophyllite-bearing assemblage is more characteristic of ?high sulfidation? epithermal rather than VHMS-related alteration assemblages. The close relationship of this assemblage to the quartz-chlorite?sericite assemblage associated with disseminated pyrite-chalcopyrite suggests that the bornite and chalcopyrite assemblages formed as two stages of one mineralizing event. The chalcopyrite-pyrite ore zone is characterised by extreme enrichment (relative to regional background) in As, Bi, Ce, Cu, Mo, Ni, S and Se. With the exception of Mo, these elements are also enriched, but at a much lower level, in the pyrite-bearing advanced argillic and sericitic halos. Positive Eu anomalies and pronounced depletion in K, Cs, Mg, Be, Ga, Rb, Y, MREE and HREE are associated with the advanced argillic assemblages. The outermost carbonate-bearing halo is highly enriched in C, Ca and Mn, and weakly enriched in Zn and Tl. The dispersion patterns and alteration assemblages observed at Western Tharsis are quite unlike those of Zn-Pb-rich volcanic-hosted massive sulfide (VHMS) deposits in western Tasmania. Rather, the dispersion patterns observed at Western Tharsis are more akin to those surrounding porphyry Cu deposits and related acid-sulfate Cu-Au deposits. Geological relationships and radiogenic isotope data may suggest an Ordovician timing for Mt Lyell Cu-Au mineral deposits.

The map of iron oxide copper-gold (IOCG) potential of the Gawler Craton, South Australia, shows the spatial distribution of key 'essential ingredients' of IOCG ore-forming systems. These 'ingredients' include: (a) rock units of the Gawler Range-Hiltaba Volcano-Plutonic Association, subdivided by supersuite; (b) faults/shear zones subdivided by interpreted age of youngest significant movement; (c) copper geochemistry (>200ppm), from drill holes intersecting crystalline basement (Mesoproterozoic and older); (d) hydrothermal alteration assemblages and zones, based on drill hole logging, potential-field interpretation, and inversion modelling of potential-field data; and (e) host sequence units considered important in localising IOCG alteration and mineralisation. Also shown are Nd isotopic data and the mineral isotopic ages of late Palaeoproterozoic to early Mesoproterozoic magmatism and hydrothermal minerals. Areas with the greatest number of 'essential ingredients' are considered to have the maximum potential for IOCG mineralisation. IOCG potential of the Gawler Craton is shown as domains with ranks from 1 to 4, with 1 being the highest rank. Notes detailing the sources of data and methods used in constructing the map are provided in a separate file available on the Geoscience Australia website.

A facsimile copy of the aerial geological and geophysical survey of Northern Australia AGGSNA Reports 1 to 26, 28, 46 to 48, 51 to 59 for Western Australia Pilbara Goldfield, consisting of scanned documents and maps.

Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The Tennant Creek goldfield, the third largest goldfield in the Northern Territory, producing over 150 tonnes of gold (Wedekind et al., 1989), was only discovered in the mid-1930s due to the association of gold with ironstone rather than quartz veins. Over the last two decades ironstone-hosted gold deposits have been included in the group of deposits termed iron-oxide copper-gold (IOCG) deposits (Hitzman et al., 1992). Elsewhere in the Northern Territory, prospects with IOCG characteristics have been recognised in the southeastern Arunta (Hussey et al., 2005), and potential for these deposits has been recognised in the Mount Webb area of the Warumpi Province (Wyborn et al., 1998). <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>