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  • Two full-colour map sheets (at 1:5 million and 1:10 million scales) that show the continental extent and age relationships of Proterozoic mafic and ultramafic rocks and associated mineral deposits throughout the continent. These rocks have been assigned to 30 Magmatic Events (ME) ranging in age from the Early Palaeoproterozoic ~2455 Ma (ME 1) to the Early Cambrian ~520 Ma (ME 30). The presence and correlation of these Magmatic Events into five Major Crustal Elements and 28 provinces are represented in a Time-Space-Event Chart on Sheet 2. Enlarged inset maps on Sheet 1 provide in more detail the polygon and line data of certain regions, and other inset maps on Sheet 2 show the distribution of Proterozoic and Archaean rocks, mineral deposits and occurrences, and five Large Igneous Provinces (LIPs). This national map supersedes two similar 'Proterozoic Mafic-Ultramafic Magmatic Events' maps relating to Western Australia (2006; GeoCat 64813) and the Northern Territory-South Australia (2007; GeoCat 65257). A user guide to the map series is described in Geocat 66624. A georeferenced image of the map Australian Proterozoic Mafic-Ultramafic Magmatic Events (Sheet 1) is also provided. The image shows spatial distribution of Proterozoic (2500 Ma to 545 Ma) mafic-ultramafic magmatic events in Australia. The map illustrates for the first time, the continental extent and age relationships of Proterozoic mafic and ultramafic rocks and their associated mineral deposits. The image has been georeferenced using ESRI ArcGIS 9.3 software. Projection: Lambert Conformal Conic Datum: Geocentric Datum of Australia 1994 False Easting: 0.00000000 False Northing: 0.00000000 Central Meridian: 134.00000000 Standard Parallel 1: -18.00000000; Standard Parallel 2: -36.00000000 Latitude Of Origin: 0.00000000 The package contains five files contained in a ZIP file [ZIP 25MB]: geo_national_mafic_part1_300dpi1.rrd geo_national_mafic_part1_300dpi1.xml geo_national_mafic_part1_300dpi1.aux geo_national_mafic_part1_300dpi1.jpg geo_national_mafic_part1_300dpi1.jwg <h3>Related products:</h3><a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=66624">Guide to Using the Australian Proterozoic Mafic-Ultramafic Magmatic Events Map</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=70461">Proterozoic Mafic-Ultramafic Magmatic Events Resource Package</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=69347">Archean Mafic-Ultramafic Magmatic Events Resource Package</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=69935">Guide to using the Australian Archean Mafic-Ultramafic Magmatic Events Map</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=69213">Proterozoic Large Igneous Provinces: Map Sheets 1 and 2</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=70008">Guide to using the Map of Australian Proterozoic Large Igneous Provinces</a>

  • 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.

  • Orogenesis in Phanerozoic systems is rapid, diachronous, episodic, and involves the switching of tectonic modes (extension-compression). In contrast, many Archaean orogens have traditionally been viewed as having developed by relatively simple, long-lived, mono-mode deformational processes. New results, however, reveal that the late Archaean eastern Yilgarn Craton (EYC) evolved episodically and rapidly, with a diachronous series of approximately E?W coaxial switches in tectonic mode. Tectonic mode switching changed stress regimes and resulted in the development of `late basins?, the emplacement of granites, and early orogenic gold mineralisation diachronously from east to west (NE?SW). Fluids were driven from the lower crust (and below) via large-scale crustal imbricating thrust faults. These fluids promoted the passage of a compression-extension couplet along a basal detachment by successively `lubricating? faults (preparing the ground), and facilitating a propagating wave of foreland surge (D2a) and hinterland extension (D2E) followed by inversion, uplift and annealing (D2b). In this way, orogenic Au and westward orogenic surge with associated tectonic mode switches are linked. We predict that the compres-sion-extension couplets and early orogenic gold mineralisation propagated from the east to the west diachronously at a rate of ~3-5 m.y. between domains from ~2670 Ma to ~2650 Ma. Multiple mineralising episodes are also a predicted consequence of the orogenic surge model.

  • The paper reveiws metallogenic evolution of Australia. A comparison between Archaean, Proterozoic and Phanerozoic metallogeny reveals that in general there exist more similarities between the Archaean and the Phanerozoic that those between the Archaean and the Proterozoic and between the Proterozoic and the Phanerozoic metallogeny. The paper argues that the contribution of plate tectonic processes in the geological evoultion and metallogeny of Australian Proterozoic need revaluation for assessing mineral potetnial of deposit styles which are traditionally considered to be not important but large deposits of each are known to exist in the Proterozoic elsewhere.

  • 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.

  • 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>

  • Initial lead isotope ratios from Archean volcanic-hosted massive sulfide (VHMS) and lode gold deposits and neodymium isotope model ages from igneous rocks from the geological provinces that host these deposits identify systematic spatial and temporal patterns, both within and between the provinces. The Abitibi-Wawa Subprovince of the Superior Province is characterized by highly juvenile lead and neodymium. Most other Archean provinces, however, are characterized by more evolved isotopes, although domains within them can be characterized by juvenile isotope ratios. Metal endowment (measured as the quantity of metal contained in geological resources per unit surface area) of VHMS and komatiite-associated nickel sulfide (KANS) deposits is related to the isotopic character, and therefore the tectonic history, of provinces that host these deposits. Provinces with extensive juvenile crust have significantly higher endowment of VHMS deposits, possibly as a consequence of higher heat flow and extension-related faults. Provinces with evolved crust have higher endowment of KANS deposits, possibly because such crust provided either a source of sulfur or a stable substrate for komatiite emplacement. In any case, initial radiogenic isotope ratios can be useful in predicting the endowment of Archean terranes for VHMS and KANS deposits. Limited data suggest similar relationships may hold in younger terranes.