The Palaeoproterozoic Murphy Inlier is situated at the southern end of the McArthur Basin in northern Australia. The inlier contains over 50 uranium, copper, tin and base metal occurrences. Fluid inclusion studies were carried out on samples of quartz veining from the uranium and copper deposits as well as from the basement rocks to determine the composition of the fluids and to investigate how uranium and copper were transported in these fluids. Four types of fluid inclusions were observed in this study; Type A vapour-rich inclusions with 30 vol.% vapour, Type B two phase aqueous inclusion with - 20 vol.% vapour, Type C multiphase inclusions with one or more solid phases and, Type D liquid-only inclusions. At least three different fluids were identified in the Murphy Inlier. The first is a high temperature fluid denoted by Types A and B inclusions which homogenise over the range from 220 to 380 ºC. In the basement rocks, this fluid is enriched in N2 indicating that it may be related to metamorphic processes. In the uranium deposits this fluid is dominated by CO2 indicating that these fluids are relatively oxidized, while in the copper deposits both CO2 and CH4 are present indicating that these fluids are more reduced than in the regions of uranium mineralisation. The second fluid is a NaCl-rich with salinities ranging from 0.2 to 29.8 mass % NaCl and the third fluid is CaCl2-rich with salinities ranging from 0.1 to 24.7 mass % CaCl2. There is also evidence for fluid mixing between the NaCl-rich and CaCl2-rich end member fluids.

The Maldon gold deposit in central Victoria has geological, geochronological and fluid chemistry characteristics that distinguish it from typical vein-hosted, orogenic' gold deposits in this region. The deposit lies within the contact aureole of the Harcourt Granite and associated granitic dykes. The ore-bearing fluids are characterised by the presence of non-aqueous (i.e. carbonic) fluids, which exhibit complex freezing and heating behaviour, as well as mixed CO2-low-salinity aqueous fluids (mostly - 10 wt.% NaCl eq.). Raman analysis indicates that carbonic inclusions can vary from CO2-rich to CH4-rich, with N2 contents up to 38 mol.%. Higher-salinity brine inclusions, 20-22 wt.% NaCl eq., only occur locally. The Harcourt Granite is a moderately reduced, I-type granite and the reduced fluids (e.g. CH4-N2-rich) are believed to have formed within (or in close proximity to) thermal aureoles of the dykes or granites during contact metamorphism. This further supports the premise that the Maldon deposit is an 'orogenic' gold deposit that was metamorphosed and/or remobilised during the emplacement of post-orogenic intrusions/dykes. We conclude that some 'orogenic' gold deposits worldwide may have been completely overprinted by later magmatic/metamorphic events and are now only evident as reduced intrusion-related gold systems.

This web-enabled system allows researchers to retrieve fluid inclusion data from anywhere in the world. The concept is to build a free and widely available web-based library of fluid properties for a range of geological fluids. The database is being developed as an "open" project, which intends to bring together researchers interested in the properties of geological fluids or fluid inclusions.

Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia (GA), in partnership with state and Northern Territory governments. The EFTF program (2016-2024) aims to drive industry investment in resource exploration in frontier regions of onshore Australia by providing new precompetitive data and information about their energy, mineral and groundwater resource potential. Under the EFTF program, the Onshore Energy Project undertook a study of petroleum prospectivity of the onshore Officer Basin in South Australia and Western Australia. Yowalga 3 well in Western Australia was selected based on the occurrence of gas and oil shows reported in the well completion report. Sampling of cuttings and cores was done at Geoscience Australia's Petroleum Data Repository in Canberra. Geoscience Australia commissioned a fluid inclusion stratigraphy (FIS) study on the downhole samples. Here, volatile components ostensibly trapped with fluid inclusions are released and analysed revealing the level of exposure of the well section to migrating fluids. Integration of thin section (TS) preparations reveal to extent of gas and fluid trapping within fluid inclusions while microthemometry (MT) gives an estimation of fluid inclusion trapping temperature. For Yowalga 3, FIS analysis was performed on 698 cuttings and 30 cores between 140 metres and 3526 metres base depth, together with 22 samples prepared for TS. To support this study, lithostratigraphic tops were compiled by Geoscience Australia. The results of the study are found in the accompanying documents. Note: Yowalga 3 results are in two parts, Part 1 and Part 2, since the total number of samples exceeded to maximum number of samples (575) for a Schlumberger well report. Part 1 has cuttings by increasing depth and Part 2 has the remaining cuttings then the cores.

Raman spectroscopy has been an invaluable method for the non-destructive analysis of fluid inclusions for over 30 years1 and since then it has also been applied to the study of melt inclusions2. While the analysis of gas species in these inclusions is relatively straight forward, the identification of stable and metastable solid phases in inclusions is more challenging due to the limited availability of reference Raman spectra for some minerals. Some examples of inclusions with challenging Raman spectra are discussed below.

This report is a synopsis of research compiled and carried out within the Predictive Mineral Discovery CRC F3 project "Micrometallogeny of hydrothermal fluids". The F3 project's original objectives were: (1) Geology-driven terrain and ore fluids investigations to evaluate the chemistry and fluid processes within mineral systems in order to extend the focus of fluid studies beyond direct ore deposit analysis. (2) LAICPMS and PIXE technique and methodology development were techniques utilized throughout the project and methodologies were developed for their combined application. (3) Diamond-cell autoclave experiments component of the project was a scoping-collaboration in year one of F3 with the Museum of South Australia. (4) Database development and fusion with numerical modelling resulted in development of a web-based database for fluid inclusion research has been successful and is currently accessed at http://www.ga.gov.au/minerals/research/methodology/geofluids/flincs_about.jsp

<div>Geoscience Australia’s Exploring for the Future program provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia’s geology and resource potential.</div><div><br></div><div>The Paleo to Mesoproterozoic Birrindudu Basin is an underexplored frontier basin located in northwestern Northern Territory and northeastern Western Australia. The Birrindudu Basin is a region of focus for the second phase of the EFTF program (2020–2024) as it contains strata of similar age to the prospective McArthur Basin, South Nicholson region and Mount Isa Province, but remains comparatively poorly understood.</div><div><br></div><div>Geoscience Australia have undertaken (via the service provider, FIT, Schlumberger) Fluid Inclusion Petrography and Microthermometry analysis of samples for the drillhole 99VRNTGSDD1, Birrindudu Basin, located in the northwest Northern Territory (Company reference number MT#F1230005c).</div><div><br></div><div>This eCat Record accompanies the report containing the results of fluid inclusion stratigraphy on this drillhole (eCat record 148973).</div>

Although the Canning Basin has yielded minor gas and oil within conventional and unconventional reservoirs, the relatively limited geological data available in this under-explored basin hinder a thorough assessment of its hydrocarbon potential. Knowledge of the Paleozoic Larapintine Petroleum Supersystem is restricted by the scarcity of samples, especially recovered natural gases, which are limited to those collected from recent exploration successes in Ordovician and Permo-Carboniferous successions along the margins of the Fitzroy Trough and Broome Platform. To address this shortcoming, gases trapped within fluid inclusions were analysed from 121 Ordovician to Permian rock samples (encompassing cores, sidewall cores and cuttings) from 70 exploration wells with elevated mud gas readings. The molecular and carbon isotopic compositions of these gases have been integrated with gas compositions derived from open-file sources and recovered gases analysed by Geoscience Australia. Fluid inclusion C1–C5 hydrocarbon gases record a snapshot of the hydrocarbon generation history. Where fluid inclusion gases and recovered gases show similar carbon isotopes, a simple filling history is likely; where they differ, a multicharge history is evident. Since some fluid inclusion gases fall outside the carbon isotopic range of recovered gases, previously unidentified gas systems may have operated in the Canning Basin. Interestingly, the carbon isotopes of the fluid-inclusion heavy wet gases converge with the carbon isotopes of the light oil liquids, indicating potential for gas–oil correlation. A regional geochemical database incorporating these analyses underpins our re-evaluation of gas systems and gas–gas correlations across the basin. <b>Citation:</b> Boreham, C.J., Edwards, D.S., Sohn, J.H., Palatty, P., Chen, J.H. and Mory, A.J., 2020. Gas systems in the onshore Canning Basin as revealed by gas trapped in fluid inclusions. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia, in partnership with state and Northern Territory governments. The first phase of the EFTF program (2016-2020) aimed to drive industry investment in resource exploration in frontier regions of northern Australia by providing new precompetitive data and information about their energy, mineral and groundwater resource potential. One key discovery was the identification of a large sedimentary depocentre concealed beneath the Cambrian Georgina Basin. This depocentre, up to 8 km deep, was termed the ‘Carrara Sub-basin’ by Geoscience Australia. It is interpreted to contain thick sequences of Proterozoic rocks, broadly equivalent to rocks of the greater McArthur Basin (Northern Territory) and northern Lawn Hill Platform and Mount Isa Province (Queensland), known to be highly prospective for sediment-hosted base metals and unconventional hydrocarbons. In order to test geological interpretations in the Carrara Sub-basin, the South Nicholson National Drilling Initiative (NDI) Carrara 1 stratigraphic drill hole was completed in late 2020, as a collaboration between Geoscience Australia, the Northern Territory Geological Survey (NTGS) and the MinEx CRC managing of the drilling operation. NDI Carrara 1 is the first drill hole to intersect Proterozoic rocks of the Carrara Sub-basin. It reached 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. Geoscience Australia has undertaken a range of investigations on the lithology, stratigraphy and geotechnical properties of NDI Carrara 1. These analyses include geochronology, isotopic studies, mineralogy, inorganic and organic geochemistry, petrophysics, geomechanics, thermal maturity, and petroleum systems investigations. To increase the understanding of the petroleum potential, molecular hydrogen and helium potential of sedimentary and basement rocks, Geoscience Australia commissioned a fluid inclusion stratigraphy (FIS) study on the downhole samples. Here, volatile components ostensibly trapped with fluid inclusions are released and analysed revealing the level of exposure of the well section to migrating fluids. Integration of thin section (TS) preparations reveal to extent of oil trapping within fluid inclusions while microthemometry (MT) gives an estimation of fluid inclusion trapping temperature. For NDI Carrara 1, FIS analysis was performed on 86 cuttings between 18 m and 282 m base depth and 342 cores between 283.9 m and 1750.45 m base depth, together with 27 samples prepared for TS and 4 samples for MT. To support this study, lithostratigraphic tops were interpreted and compiled by Geoscience Australia. The results of the study are found in the accompanying documents.

<div>Geoscience Australia’s Onshore Basin Inventories project delivers a single point of reference and creates a standardised national basin inventory that provides a whole-of-basin catalogue of geology, petroleum systems, exploration status and data coverage of hydrocarbon-prone onshore Australian sedimentary basins. In addition to summarising the current state of knowledge within each basin, the onshore basin inventory reports identify critical science questions and key exploration uncertainties that may help inform future work program planning and decision making for both government and industry. Volume 1 of the inventory covers the McArthur, South Nicholson, Georgina, Wiso, Amadeus, Warburton, Cooper and Galilee basins and Volume 2 expands this list to include the Officer, Perth and onshore Canning basins. Under Geoscience Australia’s Exploring for the Future (EFTF) program, several new onshore basin inventory reports are being delivered. Upcoming releases include the Adavale Basin of southern Queensland, and a compilation report addressing Australia’s poorly understood Mesoproterozoic basins. These are supported by value-add products that address identified data gaps and evolve regional understanding of basin evolution and prospectivity, including petroleum systems modelling, seismic reprocessing and regional geochemical studies. The Onshore Basin Inventories project continues to provide scientific and strategic direction for pre-competitive data acquisition under the EFTF work program, guiding program planning and shaping post-acquisition analysis programs.</div>