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 magnetic susceptibility analyses undertaken by Geoscience Australia on selected rock samples to establish their ability to be magnetised in an applied external magnetic field.

The National Drilling Initiative (NDI) will manage and deliver drilling programs in multiple case study areas proposed by MinEx CRC’s partner geological survey organisations. The NDI vision is to drill multiple holes in a region to map the regional geology and architecture and define the potential for mineral systems in 3D. The areas shown in this web service describe the spatial locations of the study areas.

The National Drilling Initiative (NDI) will manage and deliver drilling programs in multiple case study areas proposed by MinEx CRC’s partner geological survey organisations. The NDI vision is to drill multiple holes in a region to map the regional geology and architecture and define the potential for mineral systems in 3D. The areas shown in this web service describe the spatial locations of the study areas.

The National Drilling Initiative (NDI) will manage and deliver drilling programs in multiple case study areas proposed by MinEx CRC’s partner geological survey organisations. The NDI vision is to drill multiple holes in a region to map the regional geology and architecture and define the potential for mineral systems in 3D. The areas shown in this web service describe the spatial locations of the study areas.

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.

NDI Carrara 1 is a deep stratigraphic well 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 stratigraphic test of the Carrara Sub-Basin, a newly discovered depocentre in the South Nicholson region. The well intersected Proterozoic sediments with numerous hydrocarbon shows, likely to be of particular interest due to affinities with the known Proterozoic plays of the Beetaloo Sub-basin and the Lawn Hill Platform, including two organic-rich black shales and a thick sequence of interbedded black shales and silty-sandstones. Alongside an extensive suite of wireline logs, continuous core was recovered from 283.9 m to total depth at 1750.8 m, providing high-quality data to support comprehensive analysis. Presently, this includes geochronology, geochemistry, geomechanics, and petrophysics. Rock Eval pyrolysis data demonstrates the potential for several thick black shales to be a source of hydrocarbons for conventional and unconventional plays. Integration of these data with geomechanical properties highlights potential brittle zones within the fine-grained intervals where hydraulic stimulation is likely to enhance permeability, identifying prospective Carrara Sub-basin shale gas intervals. Detailed wireline log analysis further supports a high potential for unconventional shale resources. Interpretation of the L210 and L212 seismic surveys suggests that the intersected sequences are laterally extensive and continuous throughout the Carrara Sub-basin, potentially forming a significant new hydrocarbon province and continuing the Proterozoic shale play fairway across the Northern Territory and northwest Queensland. This abstract was submitted and presented at the 2022 Australian Petroleum Production and Exploration Association (APPEA), Brisbane (https://appea.eventsair.com/appea-2022/)

<div>NDI Carrara&nbsp;1 is a 1751 m stratigraphic drill hole completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI). This campaign was a collaboration between Geoscience Australia under the Exploring for the Future program, together with MinEx CRC and the Northern Territory Geological Survey. It is the first drillhole to intersect Proterozoic rocks of the Carrara Sub-basin, a recently discovered depocentre in the South Nicholson region. The drill hole intersected ~625 m of the Paleozoic Georgina Basin, which overlies ~1120 m of Proterozoic carbonates, black shales and siliciclastic rocks, with hydrocarbon shows encountered in both the Paleozoic and Proterozoic sections. Following the completion of the drillhole, a comprehensive analytical program was carried out by Geoscience Australia to better understand the geology of the Carrara Sub-basin and its resource potential.</div><div><br></div><div>Here we present new high-resolution strontium (87Sr/86Sr), carbon (δ13C) and oxygen (δ18O) isotope data from carbonate bearing samples of the Paleozoic Georgina Basin and the Proterozoic Lawn Hill Formation intersected in NDI Carrara&nbsp;1. The aim of this data acquisition was to provide an improved understanding of the paleo-depositional environments and local/global chemostratigraphy trends recorded in the Carrara Sub-basin. </div><div><br></div><div>The majority of samples show significant alteration and thus caution should be exercised when using this data for assessing primary depositional conditions and contemporary sea-water chemistry. Despite the altered nature of most samples, samples belonging to undifferentiated Georgina Basin preserve 87Sr/86Sr ratios close to that of mid-Cambrian seawater, indicating the sampled intervals of Georgina Basin were likely connected to the global Cambrian ocean.&nbsp;Two small positive δ13C excursions (with positive shift in δ18O) within Georgina Basin samples may coincide with reported mid-Cambrian positive δ13C global marine excursions. </div><div><br></div><div>The least altered samples from the Proterozoic Lawn Hill Formation show more radiogenic 87Sr/86Sr values than the expected value of coeval mid-Proterozoic ocean at ~1600 Ma. These radiogenic 87Sr/86Sr values may reflect (i) influx of terrigenous material into a restricted basin with reduced interaction with the global ocean, or (ii) secondary overprinting by more radiogenic diagenetic fluids.</div> Abstract/Poster submitted and presented at 2023 Australian Earth Science Convention (AESC), Perth WA (https://2023.aegc.com.au/)

<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>

<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 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>