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.

Sediment-hosted Pb-Zn (SH Pb-Zn) deposits can be divided into two sub-types: 'clastic-dominated lead-zinc' (CD Pb-Zn) ores hosted in shale, sandstone, siltstone, mixed clastic or as carbonate replacement within a clastic dominated sedimentary sequence and Mississippi Valley-type (MVT Pb-Zn) ores that occurs in platform carbonate sequences, typically in a passive margin tectonic setting. The emergence of CD and MVT deposits in the rock record between 2.02 Ga, the age of the earliest known deposit of these ores, and 1.85-1.58 Ga, a major period of CD Pb-Zn mineralization in Australia and India, corresponds to a time after the 'Great Oxygenation Event' (GOE) ca 2.4 to 1.8 Ga. Contributing to the blooming of CD deposits at ca 1.85-1.58 Ga was the following: a) enhanced oxidation of sulfides in the Earth's crust that provided sulfate and lead and zinc to the hydrosphere; b) development of major redox and compositional gradients in the oceans; c) first formation of significant sulfate-bearing evaporites; d) formation of red beds and oxidized aquifers: e) evolution of sulfate-reducing bacteria; and f) the formation of large and long-lived basins on stable cratons. A significant limitation imposed on interpreting the secular distribution of the deposits is that presently, there is no way to quantitatively evaluate the removal of deposits from the rock record through tectonic recycling. Considering that most of the sedimentary rock record has been recycled, probably most SH Pb-Zn deposits have also been destroyed by subduction and erosion or modified by metamorphism and tectonism so that they are no longer recognizable. Thus, the uneven secular distribution of SH Pb-Zn deposits reflects the genesis of these deposits, linked to Earth's evolving tectonic and geochemical systems, as well a record severely censored by an unknown amount of recycling of the sedimentary rock record.

Legacy product - no abstract available

Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The King Leopold and Halls Creek Orogens in the Kimberley region of northern Australia are divided into three distinct terranes, each representing a different tectonic setting, that may be part of a larger, diverse collisional orogen on a scale similar to the present Alpine-Himalayan Orogen. Collision with the Kimberley Craton drove intracratonic deformation in the adjacent Tanami and Arunta regions of the North Australian Craton. <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 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>

Extended abstracts from the conference

No abstract available

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.

The article describes geological constraints on the formation of sandstone-hosted uranium depoists in paleovalleyes and paleochannels

Extended abstract describing metallogenic significance of georgina-Arunta seismic line. The abstract discusses mainly the Neoproterozoic and Phanerozoic mineral potential, including implications to U, Cu-Co, Au, Cu-U and energy.