As part of Geoscience Australia's Exploring for the Future program, the East Tennant region, which is centred on the Barkly Roadhouse in the Northern Territory, was identified as having favourable geological and geophysical indicators of mineral systems potential. Potentially prospective stratigraphy in the East Tennant region is completely concealed beneath Mesoproterozoic to Quaternary cover sequences. Prior to 2020 basement rocks in the East Tennant region were only known from a handful of legacy boreholes, supported by geophysical interpretation. In order to test geophysical interpretations and obtain additional samples of basement rocks for detailed analysis, a stratigraphic drilling campaign was undertaken in the East Tennant region as part of the MinEx CRC’s National Drilling Initiative. Ten stratigraphic boreholes were drilled through the cover sequences and into basement for a total of nearly 4000 m, including over 1500 m of diamond cored basement rocks to be used for scientific purposes. Inorganic geochemical samples from East Tennant National Drilling Initiative boreholes were taken to characterise cover and basement rocks intersected during drilling. Two sampling approaches were implemented based on the rocks intersected: 1) Borehole NDIBK04 contained localised sulphide mineralisation and elevated concentrations of several economically-significant elements in portable X-ray fluorescence data. In order to understand the geochemical variability and distribution of elements important for mineral system characterisation, the entire basement interval was sampled at nominal one metre intervals. This spacing was reduced to between 0.5 and 0.25 m from 237 m to 263 m to better understand a more intense zone of mineralisation, and 2) Samples from boreholes NDIBK01, NDIBK02, NDIBK03, NDIBK05, NDIBK06, NDIBK07, NDIBK08, NDIBK09 and NDIBK10 were selected to capture lithological and geochemical variability to establish bulk rock geochemical compositions for further interpretation. Attempts were made to sample representative, lithologically consistent intervals. A total of 402 samples were selected for analysis. Sample preparation was completed at Geoscience Australia and Bureau Veritas, with all analyses performed by Bureau Veritas in Perth. All samples were submitted for X-ray fluorescence (XRF), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), FeO determination, and loss on ignition (LOI). Samples from borehole NDIBK04 also underwent total combustion C and S, and Pb collection fire assay by ICP-MS for determination of Au, Pt and Pd concentrations. This data release presents inorganic geochemistry data acquired on rock samples from the ten East Tennant National Drilling Initiative boreholes.

This Record presents new Sensitive High Resolution Ion Micro Probe (SHRIMP) in situ monazite U–Pb geochronological results from the East Tennant area that were obtained in March 2022 as part of Geoscience Australia’s (GA) Exploring for the Future (EFTF) program. Three samples were targeted for monazite geochronology in order to constrain the timing of metamorphism and ductile deformation in the East Tennant area. Monazites in cordierite schist from the Alroy Formation in drill hole NDIBK01 (NDIBK01.300) yielded a weighted mean 207Pb/206Pb age of 1843.6 ± 6.1 Ma (95% confidence). Paragneiss from the Alroy Formation in drill hole NDIBK10 (NDIBK10.009) yielded monazites that returned a weighted mean 207Pb/206Pb crystallisation age of 1843.5 ± 5.1 Ma. Sparse monazites in sample NDIBK04.300, a garnet phyllite from drill hole NDIBK04, yielded a weighted mean 207Pb/206Pb crystallisation age of 1831 ± 28 Ma. These ages, from samples distributed throughout the East Tennant area, are interpreted to constrain the timing of an episode of low pressure, medium-grade metamorphism and coeval deformation.

NDI Carrara 1 is a deep stratigraphic drill hole completed in 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. A comprehensive geochemical program designed to provide information about the region’s resource potential was carried out on samples collected at up to 4 meter intervals. This report presents part 1 of the data from Rock-Eval pyrolysis analyses undertaken by Geoscience Australia on selected rock samples to establish their total organic carbon content, hydrocarbon-generating potential and thermal maturity.

As part of Geoscience Australia’s Exploring for the Future program, this study aims to analyse the hydrocarbon prospectivity in the Carrra Sub-basin through wireline log interpretation and shale gas reservoir characterisation. NDI Carrara 1 is the first stratigraphic test of the Carrara Sub-basin, a recently uncovered depocentre located within the South Nicholson region of the eastern Northern Territory and northwestern Queensland. Four chemostratigraphic packages were defined according to the informal sub-division of stratigraphy and inorganic geochemical properties. Wireline log interpretation has been conducted to derive the clay mineral compositions, porosity, gas saturation and gas contents for the unconventional shale gas reservoirs in the Proterozoic succession in NDI Carrara 1. The predominant clay minerals include illite/muscovite, mixed-layer clay, smectite, kaolinite, and minor contents of glauconite and chlorite. The average geothermal gradient is estimated to be 35.04 °C/km with a surface temperature of 29.4 °C. The average formation pressure gradient is calculated to be < 10.7 MPa/km from mud weight records. Artificial neural network technology is used to interpret the TOC content from wireline logs for unconventional shale gas reservoirs. TOC content is positively correlated with methane and ethane concentrations in mudlog gas profiles, shale porosity, formation resistivity and gas content for NDI Carrara 1. The organic-rich shales in P2 have favourable adsorbed, free and total gas contents. The organic-rich micrites within P3 have the potential in adsorbed gas, but with very low average gas saturation (< 0.01 m3/m3). Our interpretation has identified potential shale gas reservoirs, as well as tight non-organic-rich shales and siltstones with potential as gas reservoirs. These occur throughout several of the identified chemostratigraphic packages within the Proterozoic section of NDI Carrara 1.

The Exploring for the Future program Showcase 2023 was held on 15-17 August 2023. Day 1 - 15th August talks included: Resourcing net zero – Dr Andrew Heap Our Geoscience Journey – Dr Karol Czarnota You can access the recording of the talks from YouTube here: <a href="https://youtu.be/uWMZBg4IK3g">2023 Showcase Day 1</a>

<div>The Exploring for the Future program (EFTF) is a $225M Federal Government-funded initiative spanning the period July 2016 to June 2024. This multi-disciplinary program involves aspects of method development and new pre-competitive data acquisition at a variety of scales, with the aim of building an integrated understanding of Australia’s mineral, energy and groundwater potential. Significant work has been undertaken across northern Australia within regional-scale projects and as part of national-scale data acquisition and mapping activities. Some of these activities have been largely completed, and have generated new data and products, while others are ongoing. A comprehensive overview of the EFTF program can be found via the program website (eftf.ga.gov.au). Here, we overview a range of activities with implications for resource exploration in the Northern Territory.</div><div><br></div>This Abstract was submitted & presented to the 2023 Annual Geoscience Exploration Seminar (AGES), Alice Springs (https://industry.nt.gov.au/news/2022/december/registrations-open-for-ages-2023)

<div>New SHRIMP U-Pb detrital zircon geochronology on Mesoproterozoic and Paleoproterozoic siliciclastic rocks from the South Nicholson region, in concert with recently acquired complementary regional geophysical datasets, has enabled comprehensive revision of the regional Proterozoic tectono-stratigraphy. The identification of analogous detrital zircon spectra between units deposited in half-graben hanging walls of major ENE-WSW trending extensional faults, the Benmara, Bauhinia, and Maloney-Mitchiebo faults, offers compelling evidence for regional tectono-stratigraphic correlation. Units sampled from the hanging walls of these faults are characterised by immature proximal lithofacies and host a small yet persistent population of <em>ca</em> 1640–1650 Ma aged zircon and lack Mesoproterozoic detritus, consistent with deposition coincident with extension during the River Extension event at <em>ca</em> 1640 Ma, an event previously identified from the Lawn Hill Platform in western Queensland. This finding suggests the hanging wall sequences are chrono-stratigraphically equivalent to the highly prospective sedimentary rocks of the Isa Superbasin, host to world-class sediment-hosted base metal deposits across western Queensland and north-eastern Northern Territory. Subsequent inversion of the extensional faults, resulted in development of south-verging thrusts, and exhumation of late Paleoproterozoic hanging wall siliciclastic rocks through overlying Mesoproterozoic South Nicholson Group rocks as fault propagated roll-over anticlines. These geochronology data and interpretations necessitate revision of the stratigraphy and the renaming of a number of stratigraphic units in the South Nicholson region. Accordingly, the distribution of the highly prospective late Paleoproterozoic units of the McArthur Basin, Lawn Hill Platform and Mount Isa Province is greatly expanded across the South Nicholson region. These findings imply that the previously underexplored South Nicholson region is a highly prospective greenfield for energy and mineral resources.</div> <b>Citation:</b> C. J. Carson, N. Kositcin, J. R. Anderson & P. A. Henson (2023) A revised Proterozoic tectono-stratigraphy of the South Nicholson region, Northern Territory, Australia—insights from SHRIMP U–Pb detrital zircon geochronology, <i>Australian Journal of Earth Sciences,</i> DOI: 10.1080/08120099.2023.2264355

NDI Carrara 1 is a deep stratigraphic drill hole completed in 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 newly discovered Proterozoic depocentre in the South Nicholson region, based on interpretation from new seismic surveys (L210 in 2017 and L212 in 2019) acquired as part of the Exploring for the Future program. The drill hole intersected approximately 1120 m of Proterozoic sedimentary rocks unconformably overlain by 630 m of Cambrian Georgina Basin carbonates. Continuous cores recovered from 283 m to a total depth of 1751 m. Geoscience Australia conducted an extensive post-drilling analytical program that generated over 30 datasets which the interested reader can find under the EFTF webpage (under the "Data and publications" drop down menu) at https://www.eftf.ga.gov.au/south-nicholson-national-drilling-initiative This record links to the Exploring for the Future 'borehole completion report' for NDI Carrara 1 and access to all on-site downhole geophysical datasets.

Australia remains underexplored or unexplored, boasting discovery potential in the mineral, groundwater, and energy resources hidden beneath the surface. These “greenfield” areas are key to Australia’s future prosperity and sustainability. Led by Geoscience Australia, Australia’s national government geoscience organisation, the Exploring for the Future program was a groundbreaking mission to map Australia’s mineral, energy, and groundwater systems in unparalleled scale and detail. The program has advanced our understanding of Australia’s untapped potential. Over the course of 8 years, the Exploring for the Future program provided a significant expansion of public, precompetitive geoscience data and information, equipping decision-makers with the knowledge and tools to tackle urgent challenges related to Australia’s resource prosperity, energy security, and groundwater supply.

NDI Carrara 1 is a deep stratigraphic drill hole (~1751m) completed in 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 report presents the petrology conducted on 50 selected thin sections of NDI Carrara 1 undertaken by Microanalysis Australia (under contract to Geoscience Australia as part of the Exploring for the Future program).