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  • <div>NDI Carrara 1 is a deep stratigraphic borehole that was drilled in 2020 under the MinEx CRC’s National Drilling Initiative (NDI) program in collaboration with Geoscience Australia and the Northern Territory Geological Survey. NDI Carrara 1 is the first stratigraphic test of the recently described Carrara Sub-basin, a Proterozoic aged depocentre located in the South Nicholson region of northwest Queensland and the Northern Territory. The borehole was drilled to a total depth of 1751 m and penetrated a succession of Cambrian aged Georgina Basin carbonate and siliciclastic rocks that unconformably overly a thick succession of Proterozoic age siliciclastic and carbonate-rich sediments. Although drilled on the western flank of the Carrara Sub-basin, NDI Carrara 1 did not penetrate to basement. Interpretation of the L210 deep-crustal seismic survey suggests that further Proterozoic sedimentary packages known from the northern Lawn Hill Platform in northwest Queensland are likely to be found underlying the succession intersected in NDI Carrara 1. The borehole was continuously cored from 283 m to total depth, and an extensive suite of wireline logs was acquired. Geoscience Australia and partners have undertaken an extensive analytical program to understand the depositional, structural, and diagenetic history of the sediments intersected in NDI Carrara 1. This program includes a targeted geomechanical study that aims to characterise the physical properties of these Proterozoic rocks through laboratory analysis of core samples, the results of which are summarised in this data release.</div><div><br></div><div>This data release provides data from new unconfined compressive strength (UCS), single-stage triaxial testing, and laboratory ultrasonic testing for 36 sample plugs from NDI Carrara 1. These tests were performed at the CSIRO Geomechanics and Geophysics Laboratory in Perth, during January to June 2022. The full results as provided by CSIRO to Geoscience Australia are provided as an attachment to this document.&nbsp;</div>

  • <div>This study was commissioned by Geoscience Australia (GA) to produce a report on seal capacity of select samples from the deep stratigraphic hole NDI Carrara 1, located in the Proterozoic Carrara Sub-basin in the Northern Territory. Plugs were taken from depths of interest and analysed via mercury injection capillary pressure testing. Results were provided as two reports, Part A and Part B and demonstrate that the analysed samples are capable of sealing very large columns of both methane and carbon dioxide.</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. 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, $225 m investment by the Australian Government. </div><div>As part of this program, Geoscience Australia led two deep crustal reflection seismic surveys in the South Nicholson region, revealing the existence of the Carrara Sub-basin, a large sedimentary depocentre up to 8 km deep, beneath the Georgina Basin (Carr et al., 2019; 2020). The depocentre is believed to contain thick sequences of highly prospective Proterozoic rocks for base metals and unconventional hydrocarbons. To confirm geological interpretations and assess resource potential, the 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 (Geoscience Australia, 2021). NDI Carrara 1 is located on the western flank of the Carrara Sub-basin on the South Nicholson seismic line (17GA-SN1) (Figure 1.1; Figure 1.2), reaching a total depth of 1751 m, intersecting sedimentary rocks comprising ca. 630 m of Cambrian calcareous shales of the Georgina Basin and ca. 1100 m of Proterozoic carbonates and siliciclastics that include black shales of the Carrara Sub-basin.</div><div>This report presents data on selected rock samples from NDI Carrara&nbsp;1, conducted by the Mawson Analytical Spectrometry Services, University of Adelaide, under contract to Geoscience Australia. These results include bulk carbon isotope ratios (δ13C) of bitumens and isolated kerogens. In addition, a selection of 10 samples was analysed at Geoscience Australia for comparison purposes.</div><div><br></div>

  • <div><strong>Output type: </strong>Exploring for the Future Extended Abstract </div><div><br></div><div><strong>Short Abstract: </strong>The Delamerian Orogen, with a length of ~1000 km on mainland Australia and a proven potential to host mineralisation, represents an evolving exploration opportunity. However, uncertainty surrounding the age and tectonic setting of the orogen is a barrier to confident exploration in frontier covered regions, such as the Loch Lilly-Kars Belt in western New South Wales and South Australia. A major area of uncertainty is the configuration and extent of the Cambrian convergent-margin system and lateral variations thereof. In this study, we highlight multidisciplinary data from new and legacy sources, including lithology, geochronology, geochemistry, potential-field geophysics, deep-crustal seismic, and magnetotelluric data that permit a revised interpretation of the geological framework for the Delamerian Orogen in mainland Australia, with an emphasis on the covered, central part of the system. These data indicate that a largely continuous, east-facing volcanic arc developed in the Delamerian Orogen in the Cambrian. The arc transitions from exhibiting a strong continental affinity in the Koonenberry Belt to having less continental affinity in the Grampians-Stavely Zone of Victoria. The Loch Lilly-Kars Belt is interpreted to have occupied a volcanic arc to incipient back-arc position in the middle Cambrian.&nbsp;</div><div><br></div><div><strong>Citation: </strong>Clark A.D., et al., 2024. Cambrian convergent margin configuration in the Delamerian Orogen of mainland Australia. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://doi.org/10.26186/149647 </div>

  • <div>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. The drilling aimed to gather new subsurface data on the potential mineral and energy resources in the newly identified Carrara Sub-basin. NDI Carrara 1 is located in the eastern Northern Territory, on the western flanks of the Carrara Sub-basin on the South Nicholson Seismic line, 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 (https://portal.ga.gov.au/bhcr/minerals/648482).</div><div>&nbsp;</div><div>Following a public data release of the borehole completion report, CSIRO was contracted by Geoscience Australia (GA) under the Exploring for the Future program to analyse samples from NDI Carrara 1 for quantitative bulk and clay fraction analysis. This report presents results for quantitative bulk and clay (<2 µm) fraction analysis by X-ray powder diffraction (XRD) on 32 bulk core samples from the NDI Carrara 1. Samples were prepared and analysed at the CSIRO’s Waite Laboratories in South Australia.</div><div><br></div>

  • A comprehensive geochemical program was carried out on rock samples collected in the NDI Carrara 1 drill hole, the first stratigraphic test of the newly discovered Carrara Sub-basin located in the South Nicholson region of northern Australia. The drill hole recovered continuous core from 284 m to total depth at 1750 m and intersected approximately 1120 m of Proterozoic sedimentary rocks, unconformably overlain by 630 m of Cambrian Georgina Basin carbonate-rich rocks. Total organic carbon (TOC) contents from Rock-Eval pyrolysis highlight the potential for several thick black shales to be a source of petroleum for conventional and unconventional plays. Cambrian rocks contain an organic-rich section with TOC contents of up to 4.7 wt.% and excellent oil-generating potential. The Proterozoic section is overmature for oil generation but mature for gas generation, with potential for generating gas in carbonaceous mudstones showing TOC contents up to 5.5 wt.% between 680 and 725 m depth. A sustained release of methane (up to 2%) recorded during drilling from 1150 to 1500 m suggests potential for an unconventional gas system in the Proterozoic rocks from 950 to 1415 m depth, which exhibit favourable organic richness and thermal maturity. The Proterozoic rocks, which are comparable in age to the sediment-hosted deposits of the Century Mine, contain local occurrences of lead, zinc and copper sulfide minerals providing hints of mineralisation. The combined geochemical results offer the promise of a potential new resource province in northern Australia. <b>Citation:</b> E. Grosjean, A.J.M. Jarrett, C.J. Boreham, L. Wang, L. Johnson, J.M. Hope, P. Ranasinghe, J.J. Brocks, A.H.E. Bailey, G.A. Butcher, C.J. Carson, Resource potential of the Proterozoic–Paleozoic Carrara depocentre, South Nicholson region, Australia: Insights from stratigraphic drilling, <i>Organic Geochemistry</i>, Volume 186, 2023, 104688, ISSN 0146-6380, DOI: https://doi.org/10.1016/j.orggeochem.2023.104688.

  • <div>This report presents thermal property data (thermal conductivity data, calculated heat production data, and calculated surface heat flow) from the deep (1751 m) stratigraphic drill hole, NDI Carrara 1. Thermal conductivity analyses were undertaken at the University of Melbourne. Heat production values were calculated from existing whole rock geochemical data. Surface heat flow was determined using the laboratory thermal conductivity data together with in situ downhole temperature data collected previously.</div>

  • <div>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 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.</div>

  • <div>The Darling-Curnamona-Delamerian (DCD) project focused on the covered portion of the Delamerian orogen, situated in the south-eastern mainland states of Australia.&nbsp;The aims of the project were to develop a greater understanding of the geodynamic history of the Delamerian Orogen, characterise known magmatic-hydrothermal mineral systems, and assess mineral potential for a suite of minerals including copper (Cu), gold (Au), and nickel (Ni), and critical minerals like platinum-group elements (PGEs) and rare-earth elements (REEs). </div><div>Here, we collate whole rock geochemistry data from new and legacy samples of mafic to intermediate magmatic rocks of the Loch Lilly-Kars Belt in order to determine the likely source of these magmas and constrain the prevailing tectonic setting during their emplacement. We apply multi-elemental diagrams and various elemental discrimination diagrams to characterise various groups of magmatic rocks in these belts, taking into account their geographic affinity and new geochronological data (e.g. Mole et al., 2023; Mole et al., 2024). The geochemical characteristics of these groups and the implications for the tectonic setting into which they were emplaced are discussed. Comparisons are made with potentially similar magmatic rocks of the&nbsp;Koonenberry Belt and Grampians-Stavely Zone. Results from this study have significant implications for the tectonic setting in which the Loch Lilly-Kars Belt developed, and hence also the mineral potential of the Belt. </div><div> </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.</div><div><br></div><div>In order to gain insights into the resource potential of the South Nicholson region, a key region of focus for EFTF, National Drilling Initiative (NDI) Carrara&nbsp;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. NDI Carrara&nbsp;1 is the first drill hole to intersect the, as yet, undifferentiated Proterozoic rocks of the newly defined Carrara Sub-Basin within the South Nicholson region. NDI Carrara&nbsp;1 is located on the western flank of the Carrara Sub-basin, reaching a total depth of 1751&nbsp;m, intersecting ca. 630&nbsp;m of Cambrian Georgina Basin overlying ca. 1100&nbsp;m of Proterozoic carbonates, black shales and minor siliciclastics.</div><div><br></div><div>Geoscience Australia is undertaking a range of investigations on the lithology, stratigraphy and geotechnical properties of NDI Carrara&nbsp;1 based on wireline data, as well as undertaking a range of analyses of over 400 physical samples recovered through the entire core. These analyses include geochronology, isotopic studies, mineralogy, inorganic and organic geochemistry, petrophysics, geomechanics, thermal maturity, and petroleum systems investigations. Hylogger™ data is available at the NTGS Geoscience Exploration and Mining Information System (GEMIS) webpage.</div><div><br></div><div>This data release presents results for analyses on selected rock samples from NDI Carrara 1, conducted by the Mawson Analytical Spectrometry Services, University of Adelaide, under contract to Geoscience Australia. These results include:</div><div><br></div><div>1.&nbsp;&nbsp;&nbsp;&nbsp;Carbon (δ13C), oxygen (δ18O) and strontium (87Sr/86Sr) isotopes on carbonate bearing samples, and</div><div>2.&nbsp;&nbsp;&nbsp;&nbsp;Trace element data on the leachates prepared for 87Sr/86Sr ratio analyses.</div><div><br></div>