The Paleoproterozoic Westmoreland region is located 1250 km southeast of Darwin. The Westmoreland region is flanked on the southeast by the Paleoproterozoic Mt Isa Inlier and the Neoproterozoic South Nicholson Basin and in the northwest it is overlapped by Mesoproterozoic sediments of the McArthur Basin. The northern and southern ends of the McArthur basin share many geologic attributes including correlative stratigraphic rock types, which suggests that there is potential for unconformity-related uranium deposits in the southern McArthur basin and adjacent Westmoreland region. In fact, over fifty occurrences of uranium (some with minor gold) and copper mineralisation have been recorded in the Westmoreland region. Fluid inclusion studies have been carried out on selected uranium and copper prospects on the Northern Territory side of the Westmoreland region. Four types of inclusions have been observed, (Type A) Vapour-rich inclusions containing 30 100 vol.% vapour. Varying amounts of CO2 ± N2 ± CH4 have been detected in these inclusions, (Type B) Liquid-rich inclusions with up to 30 vol.% vapour, (Type C) Liquid-only inclusions, and (Type D) Three-phase (vapour + liquid + solid) liquid-rich inclusions containing a small daughter crystal. Type A, vapour-rich inclusions and some Type B, liquid-rich inclusions homogenised over the range 171 to 385 °C and are thought to be related to early metamorphic events. Other Type B and Type D inclusions typically homogenised between 100 and 240 °C with a mode around 120 °C, while the presence of liquid-only inclusions suggests trapping at temperatures below 50 °C. Eutectic melting temperatures indicate the presence of CaCl2 in the fluids but final melting temperatures show the presence of both high and low salinity brines. This suggests mixing between saline basinal fluids and low salinity meteoric fluids that continued down to temperatures below 50 °C.

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.

Geoscience Australia’s Exploring for the Future (EFTF) 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. This leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia’s transition to a low emissions economy, strong resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The Exploring for the Future program, which commenced in 2016, is an eight year, $225m investment by the Australian Government. The deep stratigraphic drill hole, NDI Carrara 1 (~1751 m), was completed in December 2020 as part of the MinEx CRC National Drilling Initiative (NDI) in collaboration with Geoscience Australia and the Northern Territory Geological Survey. It is the first test of the Carrara Sub-basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys (L210 in 2017 and L212 in 2019) recently acquired as part of the Exploring for the Future program. The drill hole intersected approximately 1100 m of Proterozoic sedimentary rocks uncomformably overlain by 630 m of Cambrian Georgina Basin carbonates. This contractor report (FIT - Schlumberger) presents hydrocarbon and aqueous fluid inclusion petrology and data (micro-thermometry, salinities etc.) on four hydrocarbon-bearing calcite veins sampled from NDI Carrara 1 between 762.56-763.60 m depth, (under contract to, and fully funded by, Geoscience Australia as part of the Exploring for the Future program).

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 Basin Inventory Project undertook a study of petroleum prospectivity of the onshore Eromanga Basin in Queensland and South Australia. Yongala 1 well in Queensland 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 the extent of gas and fluid trapping within fluid inclusions while microthemometry (MT) gives an estimation of fluid inclusion trapping temperature. For Yongala 1, FIS analysis was performed on 418 cuttings and 52 cores between 15.2 metres and 3104.5 metres base depth, together with 22 samples prepared for TS and 3 samples for MT. To support this study, lithostratigraphic tops were 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>

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.

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.

<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>

<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 WLMB001B, Birrindudu Basin, located in the northwest Northern Territory (Company reference number MT#FI230004a).</div><div><br></div><div>This eCat Record accompanies the report containing the results of fluid inclusion stratigraphy on this drillhole (eCat record 149178)</div>

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, GA’s National Hydrogen Project and in collaboration with Minerals Resources Tasmania (MRT) undertook a study of hydrogen and helium potential of south-east Tasmania with the sampling of cores from Glenorchy 1 in the surrounds of Hobart. This well was selected based on the availability of core and historic reports of hydrogen-rich natural gases from petroleum exploration wells in the region. Sampling of cores was done at MRT’s Core Repository in Hobart. 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 the extent of gas and fluid trapping within fluid inclusions while microthemometry (MT) gives an estimation of fluid inclusion trapping temperature. For Glenorchy 1, FIS analysis was performed on 173 cores between 6 m and 613.9 m base depth, together with 8 samples prepared for TS and 1 sample for MT. To support this study, lithostratigraphic tops were compiled by MRT. The results of the study are found in the accompanying documents.