Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The Early Mesoproterozoic (1600 Ma - 1570 Ma) was a period of widespread compressional tectonism and high geothermal gradient metamorphism in the Australian Proterozoic. In the eastern half of the North Australian Craton, the bulk of Palaeoproterozoic terrains underwent high-temperature tectonism between 1600 Ma to 1550 Ma. In central Australia, the Chewings Orogeny (1600 Ma - 1570 Ma) was associated with approximately north-south shortening coeval with regional low-pressure high-temperature metamorphism up to granulite grade. In northeastern Australia, the Early Isan (1600 Ma - 1580 Ma), and Ewamin-Janan Orogenies (1585 Ma - 1555 Ma) in the Mt Isa and Georgetown and Yambo Inliers, respectively, were also associated with approximately north-south shortening and high geothermal gradient metamorphism. In the southern Australian Proterozoic, the Olarian Orogeny (1610 Ma - 1585 Ma) in the Curnamona Province was also characterised by high geothermal gradient metamorphism. <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 North Australia Project (NAP) was initiated in July 2000 following negotiations between the Northern Territory Geological Survey (NTGS) and the Australian Geological Survey Organisation (now Geoscience Australia). The NAP was a joint project undertaking geoscientific studies in the Tanami, Arunta and Tennant regions of central Australia to help encourage mineral exploration. The project continued until June 2004, when the Geological Survey of Western Australia (GSWA) began regional data acquisition in the western Tanami region. In July 2004, the Tanami Project, a joint initiative between Geoscience Australia, NTGS, and GSWA to increase mineral exploration replaced the NAP. Although NTGS and GSWA have continued interests in the Tanami and Arunta regions, the collaborative Tanami Project will finish in December 2006. The purpose of this product is to provide reports and datasets summarising the results of the project at this time. The only major products not included in this DVD are the results of the Tanami seismic survey and modifications to the on-line 3D models required by the seismic results. These will be released separately, beginning in August 2006. As this report is intended to be as up-to-date as possible, it refers to a number of manuscripts that are either in press or in preparation. Although these manuscripts cannot be provided here, much of the data upon which the conclusions are based are presented in summary, either in abstracts, presentations, or data tables.

Geochronological constraints on tourmaline formation in the Western Fold Belt of the Mount Isa Inlier, Australia: Evidence for large-scale metamorphism at 1.57 Ga?

Decrepitation and degassing behaviour of quartz up to 1560 °C: Analysis of noble gases and halogens in complex fluid inclusion assemblages

Noble gas and halogen constraints on mineralizing fluids of metamorphic versus surficial origin: Mt Isa, Australia

Mid-crustal fluid mixing in a Proterozoic Fe oxide Cu Au deposit, Ernest Henry, Australia: Evidence from Ar, Kr, Xe, Cl, Br, and I

Metamorphic fluid origins in the Osborne Fe oxide Cu Au deposit, Australia: evidence from noble gases and halogens

Tracing the sources of CO2 in metamorphic belts with Ne and Ar: A fluid inclusion case study, northeast Australia.

Quantitative extraction of noble gases by in vacuo crushing: Implications for Ar-Ar dating and measurement of scapolite Br/Cl and I/Cl

Australia's nickel sulfide industry has had a fluctuating history since the discovery in 1966 of massive sulfides at Kambalda in the Eastern Goldfields of Western Australia. Periods of buoyant nickel prices and high demand, speculative exploration, and frenetic investment (the 'nickel boom' years) have been interspersed by protracted periods of relatively depressed metal prices, exploration inactivity, and low discovery rates. Despite this unpredictable evolution, the industry has had a significant impact on the world nickel scene with Australia having a global resource of nickel metal from sulfide ores of not, vert, similar 12.9 Mt, five world-class deposits (> 1 Mt contained Ni), and a production status of number three after Russia and Canada. More than 90% of the nation's known global resources of nickel metal from sulfide sources were discovered during the relative short period of 1966 to 1973. Australia's nickel sulfide deposits are associated with ultramafic and/or mafic igneous rocks in three major geotectonic settings: (1) Archean komatiites emplaced in rift zones of granite-greenstone belts; (2) Precambrian tholeiitic mafic-ultramafic intrusions emplaced in rift zones of Archean cratons and Proterozoic orogens; and (3) hydrothermal-remobilized deposits of various ages and settings. The komatiitic association is economically by far the most important, accounting for more than 95% of the nation's identified nickel sulfide resources. The ages of Australian komatiitic- and tholeiitic-hosted deposits generally correlate with three major global-scale nickel-metallogenic events at not, vert, similar 3000 Ma, not, vert, similar 2700 Ma, and not, vert, similar 1900 Ma. These events are interpreted to correspond to periods of juvenile crustal growth and the development of large volumes of primitive komatiitic and tholeiitic magmas caused by large-scale mantle overturn and mantle plume activities. There is considerable potential for the further discovery of komatiite-hosted deposits in Archean granite-greenstone terranes including both large, and smaller high-grade (5 to 9% Ni) deposits, that may be enriched in PGEs (2 to 5 g/t), especially where the host ultramafic sequences are poorly exposed. Analysis of the major komatiite provinces of the world reveals that fertile komatiitic sequences are generally of late Archean (not, vert, similar 2700 Ma) or Paleoproterozoic (not, vert, similar 1900 Ma) age, have dominantly Al-undepleted (Al2O3/TiO2 = 15 to 25) chemical affinities, and often occur with sulfur-bearing country rocks in dynamic high-magma-flux environments, such as compound sheet flows with internal pathways facies (Kambalda-type) or dunitic compound sheet flow facies (Mt Keith-type). Most Precambrian provinces in Australia, particularly the Proterozoic orogenic belts, contain an abundance of sulfur-saturated tholeiitic mafic ± ultramafic intrusions that have not been fully investigated for their potential to host basal Ni-Cu sulfides (Voisey's Bay-type mineralization). The major exploration challenges for finding these deposits are to determine the pre-deformational geometries and younging directions of the intrusions, and to locate structural depressions in the basal contacts and feeder conduits under cover. Stratabound PGE-Ni-Cu ± Cr deposits hosted by large Archean-Proterozoic layered mafic-ultramafic intrusions (Munni Munni, Panton) of tholeiitic affinity have comparable global nickel resources to many komatiite deposits, but low-grades (< 0.2% Ni). There are also hydrothermal nickel sulfide deposits, including the unusual Avebury deposit in western Tasmania, and some potential for 'Noril'sk-type' Ni-Cu-PGE deposits associated with major flood basaltic provinces in western and northern Australia.