Aspects of the tectonic history of Paleo- to Mesoproterozoic Australia are recorded by metasedimentary basins in the Mt Isa, Etheridge Provinces, and Coen Inlier in northern Australia and in the Curnamona Province of southern Australia. These deformed and metamorphosed basins are interpreted to have been deposited in a tectonically-linked system based on similarities in depositional ages and stratigraphy (Giles at al 2002). Neodymium isotope compositions of sediments and felsic volcanics, when combined with U-Pb geochronology, are independent data that are important tools for inferring tectonic setting, palaeogeography and sediment provenance in deformed and metamorphosed terrains.

Single-copounds carbon isotops of Precambrian eviporates.

Metallogenic, geologic and isotopic data indicate secular changes in the character of VHMS deposits relate to changes in tectonic processes, tectonic cycles, and changes in the hydrosphere and atmosphere. The distribution of these deposits is episodic, with peaks at 2740-2680 Ma, 1910-1840 Ma, 510-460 Ma and 370-355 Ma that correspond to the assembly of Kenorland, Nuna, Gondwana and Pangea. Quiescent periods of VHMS formation correspond to periods of supercontinent stability. Large ranges in source 238U/204Pb that characterize VHMS deposits in the Archean and Proterozoic indicate early (Hadean to Paleoarchean) differentiation. A progressive decrease in - variability suggests homogenisation with time of these differentiated sources. Secular increases in the amount of lead and decreases in 100Zn/(Zn+Pb) relate to an increase in felsic-dominated sequences as hosts to deposits and an absolute increase in the abundance of lead in the crust with time. The increase in sulfate minerals in VHMS deposits from virtually absent in the Meso- to Neoarchean to relatively common in the Phanerozoic relates to oxidation of the hydrosphere. Total sulfur in the oceans increased, resulting in an increasingly important contribution of seawater sulfur to VHMS ore fluids with time. Most sulfur in Archean to Paleoproterozoic deposits was derived by leaching rocks below deposits, with little contribution from seawater, resulting in uniform, near-zero-permil values of 34Ssulfide. In contrast the more variable values of younger deposits reflect the increasing importance of seawater sulfur. Unlike Meso- to Neoarchean deposits, Paleoarchean deposits contain abundant barite, which is inferred to have been derived from photolytic decomposition of atmospheric SO2 and does not reflect overall oxidised oceans. Archean and Proterozoic seawater was more salty than Phanerozoic, particularly upper Phanerozoic, seawater. VHMS fluids ore fluids reflect this, also being saltier in Precambrian deposits.

Throughout New Zealand, the Torlesse Supergroup forms an extensive Permian to Cretaceous accretionary wedge of rather monotonous, sandstone-dominated turbidites. In contrast to contemporaneous rocks in neighbouring terranes within the accretionary wedge, the turbidites have less intermediate-volcaniclastic compositions, and show more quartzose, continent-derived, plutonic provenances. Petrographic, geochemical, isotopic and detrital mineral age characteristics all indicate that they did not originate at the contemporary Gondwanaland margin in New Zealand, but rather, constitute a suspect terrane (Torlesse Terrane), having sediment sources elsewhere along the margin. This latter subject has been controversial, with sediment sources suggested in Antarctica, southern South America and northeast Australia, but detailed Torlesse detrital mineral (zircon and mica) age data and bulk rock Sr-isotope patterns can be best matched for the most part with Carboniferous, Permian and Triassic sources in the New England Orogen, and the remainder with Cambrian and Ordovician sources in its hinterland.

Vertical geochemical profiling of the marine Toolebuc Formation, Eromanga Basin - implications for shale gas/oil potential The regionally extensive, marine, mid-Cretaceous (Albian) Toolebuc Formation, Eromanga Basin hosts one of Australia's most prolific potential source rocks. However, its general low thermal maturity precludes pervasive petroleum generation, although regions of high heat flow and/or deeper burial may make it attractive for unconventional (shale gas and shale oil) hydrocarbon exploration. Previous studies have provided a good understanding of the geographic distribution of the marine organic matter in the Toolebuc Formation where total organic carbon (TOC) contents range to over 20% with approx. half being of labile carbon and convertible to gas and oil. This study focuses on the vertical profiling, at the decimetre to metre scale, of the organic and inorganic geochemical fingerprints within the Toolebuc Formation with a view to quantify fluctuations in the depositional environment and mode of preservation of the organic matter and how these factors influence hydrocarbon generation thresholds. The Toolebuc Formation from three wells, Julia Creek-2 and Wallimbulla-2 and -3, was sampled over an interval from 172 to 360m depth. The total core length was 27m from which 60 samples were selected. Cores from the underlying Wallumbilla Formation (11 samples over 13m) and the overlying Allaru Mudstone (3 samples) completed the sample set. Bulk geochemical analyses included %TOC, %carbonate, %total S, -15N kerogen, -13C kerogen, -13C carbonate, -18O carbonate, and major, minor and tracer elements and quantitative mineralogy. More detailed organic geochemical analyses involved molecular fossils (saturated and aromatic hydrocarbons, and metalloporphyrins), compound specific carbon isotopes of n-alkanes, pyrolysis-gas chromatography and compositional kinetics. etc.

As recognised by the Academy of Science's UNCOVER group in their `Searching the Deep Earth' document, a goal for geoscientific advancement in Australia is a `holistic understanding of our continent so that we might better predict the location of large-scale mineral systems. This view included the investigation of Australia's lithospheric architecture to establish a whole-of-lithosphere architectural framework as a priority. An important component of the Earth's lithosphere is the crust, most of which is clearly inaccessible. Just as the study of basaltic rocks has provided insight into the earth's mantle, granites provide a (not always wholly transparent) window into the middle and lower continental crust. Studies of these rocks are enhanced by isotopic tracers, such as Samarium-Neodymium, which can affectively `see through' the granite to provide constraints on crustal formation, and enable us to map the Australian crust. This approach and the application of Samarium-Neodymium isotope data were used by Geoscience Australia for the Archean Yilgarn Craton of Western Australia. Studies in that region showed that regional scale Samarium-Neodymium signatures in felsic igneous rocks (tonalite to granite and volcanic equivalents) were not only able to map crustal architecture but that this architecture had unexpected correlations with mineralisation. The successful results in the Yilgarn Craton, coupled with the UNCOVER focus, warranted that this approach be extended to the whole of the continent to test its general applicability for crustal mapping and predicting mineralisation. A database of Sm-Nd isotopic data, and associated metadata, for >2650 samples of Australian rocks was compiled from published and unpublished sources. This included location, unit, geochronology and bibliographic data and metadata for all data points; this dataset is available for download at www.ga.gov.au. Data were compiled for a range of lithologies, including felsic and mafic igneous rocks, sedimentary rocks, as well as some mineral data. Just over 1630 of these data points were from felsic igneous rocks which had reliable locational details and a reasonable estimated or known magmatic age. A comparison of the magmatic ages from these samples with compilations of Australian igneous rock ages showed a generally good agreement confirming the representative nature of the compiled Nd data set.

Inland sulfidic soils have recently formed throughout wetlands of the Murray River floodplain associated with increased salinity and river regulation (Lamontagne et al., 2006). Sulfides have the potential to cause widespread environmental degradation both within sulfidic soils and down stream depending on the amount of carbonate available to neutralise acidity (Dent, 1986). Sulfate reduction is facilitated by organic carbon decomposition, however, little is known about the sources of sedimentary organic carbon and carbonate or the process of sulfide accumulation within inland sulfidic wetlands. This investigation uses stable isotopes from organic carbon (13C and 15N), inorganic sulfur (34S) and carbonate (13C and 18O) to elucidate the sources and cycling of sulfur and carbon within sulfidic soils of the Loveday Disposal Basin.

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.

The Victoria and Birrindudu Basins of the Victoria River region, NW Northern Territory, represent a pair of stacked unmetamorphosed Palaeoproterozoic to Neoproterozoic basins unconformably overlying low-grade metamorphic basement. SHRIMP U-Pb analysis of detrital zircons provide a basis for lithostratigraphic correlations with other Proterozoic Basins across northern Australia. The Palaeoproterozoic Stirling Sandstone (basal Limbunya Group) is tentatively correlated with the Mount Charles Formation in the Tanami region. The Jasper Gorge Sandstone (basal Auvergne Group) correlates with basal units of the lower Cryogenian Supersequence 1 of the Centralian Superbasin (Heavitree Quartzite and its correlatives). A third correlation, previously proposed elsewhere and further explored here, suggests that the Duerdin Group may correlate with the upper Cryogenian ca. 635 Ma 'Marinoan' glacigenic units of Supersequence 3 of Centralian Superbasin. In particular, the Cryogenian pre-glacigenic Black Point Sandstone Member (basal Duerdin Group) is dominated by detrital zircons with age components characteristic of the Musgrave Complex, implying significant exhumation and erosion of the Musgrave Complex occurred, at least partially, prior to the end of the Cryogenian (<ca. 635 Ma) far earlier than generally thought. The latter two correlations suggest that the Victoria Basin in the Victoria River region represents yet another relic component of the extensive former Centralian Superbasin, at least during Cryogenian time. Sm-Nd whole rock determinations overwhelmingly, and unsurprisingly, are consistent with clastic derivation from the evolved North Australian Craton and, for the Black Point Sandstone Member, from the Musgrave Complex. A relatively juvenile signature ('Ndt ' +1) is observed coincident with aerial volcanism within the Birrindudu Basin at ca. 1640 Ma as has been recently noted in other Australian Palaeoproterozoic terrains.

<div>Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia, in partnership with state and Northern Territory governments, and aimed at stimulating exploration now to ensure a sustainable, long-term future for Australia through an improved understanding of the nation’s minerals, energy and groundwater resource potential. </div><div>The EFTF program is currently focused on eight interrelated projects, united in growing our understanding of subsurface geology. One of these projects, the Barkly–Isa–Georgetown project, will deliver new data and knowledge to assess the mineral and energy potential in undercover regions between Tennant Creek, Mount Isa and Georgetown. Building on the work completed in the first four years of the Exploring for the Future program (2016-2020), the project undertook stratigraphic drilling in the East Tennant and South Nicholson regions, in collaboration with MinEx CRC and the Northern Territory Geological Survey (NTGS). This work tests geological interpretations and the inferred mineral and energy potential of these covered regions. Geoscience Australia is undertaking a range of analyses on physical samples from these drill holes including geochemistry and geochronology. </div><div>The South Nicholson National Drilling Initiative (NDI) Carrara 1 drill hole is the first drillhole to intersect the Proterozoic rocks of the Carrara Sub-Basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys acquired as part of the EFTF. It is located on the western flanks of the Carrara Sub-basin on the South Nicholson Seismic line 17GA-SN1, reaching a total depth of 1751 m, intersecting ca. 630 m of Cambrian Georgina Basin overlying ca. 1100 m of Proterozoic carbonates, black shales and minor siliciclastics.</div><div>The NDI BK10 drill hole is the tenth drill hole drilled as part of the East Tennant project aimed to constrain the East Tennant basement geology and calibrate predictive mineral potential maps to further our understanding of the prospectivity of this region. NDI BK10 reached a depth of 766 m and intersected basement at 734 m. Overlying these basement metasediments of the Alroy Formation, the drillhole intersected about 440 m of Proterozoic rocks underlain by ca. 300 m rocks of Cambrian age from the Georgina Basin.</div><div>During coring of NDI Carrara 1 and NDI BK10, cores containing oil stains were identified and sent for geochemical analysis to Geoscience Australia. This report presents the geochemical data from these oil stains including biomarker and isotopic data.</div>