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).

Stratigraphic drill hole NDI Carrara 1 was drilled as a collaboration between Geoscience Australia (GA), the Northern Territory Geological Survey (NTGS) and the Mineral Exploration Cooperative Research Centre (MinEx CRC). It reached a total depth of 1751 m in late 2020 and is the first drill hole to intersect the undifferentiated Proterozoic rocks of the Carrara Sub-Basin. It intersected approximately 630 m of Cambrian Georgina Basin sedimentary rocks overlying the ~1100 m of Proterozoic carbonates, black shales and other siliciclastics of the Carrara Sub-Basin succession. The formational assignments of the Georgina Basin succession are preliminary and were assigned in the field. The units intersected comprise the Border Waterhole Formation (~531m to ~630m), which is overlain by the Currant Bush Limestone (~249m to ~531m), which in turn is overlain by the Camooweal Dolostone (0m to ~249m). Of these, only the lower 80% of the Currant Bush Limestone and the entire Border Waterhole Formation were cored. This report presents biostratigraphic results from macrofossil examination of NDI Carrara 1 core samples within the Georgina Basin section.

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.

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 inorganic geochemical analyses undertaken by Geoscience Australia on selected rock samples, collected at roughly 4 m intervals.

<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 petrophysical 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 X-ray Computerised Tomography (XCT) scanning and gas porosity and permeability testing for 32 samples from NDI Carrara 1. Additional low permeability tests were undertaken on select samples that were identified as being ultra-tight (permeability <1 μD). 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>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>The Carrara Sub-basin, discovered in 2017 based on interpretation of 2D deep seismic surveys acquired by Geoscience Australia, is a large sedimentary depocentre in the South Nicholson region straddling the Northern Territory and Queensland. It was interpreted to contain up to 8 km of Paleoproterozoic to Cambrian rocks including stratigraphic equivalents to the Isa Superbasin, South Nicholson Group and Georgina Basin. In order to validate these stratigraphic interpretations and assess the resource prospectivity of 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 the MinEx Cooperative Research Centre, Geoscience Australia and the Northern Territory Geological Survey. NDI Carrara 1 was drilled on the western flanks of the Carrara Sub-basin and reached 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. More than 400 NDI Carrara&nbsp;1 physical samples were analysed as part of an extensive geochemical program, including Rock-Eval pyrolysis and compositional analyses of hydrocarbon shows, whose results and implications for energy prospectivity are summarised here.</div> This Abstract was submitted/presented to the 2022 Australian Organic Geochemistry Conference 27-29 November (https://events.csiro.au/Events/2022/October/5/Australian-Organic-Geochemistry-Conference)

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 SHRIMP U-Pb zircon geochronology on 10 volcaniclastic rocks taken from NDI Carrara 1.

<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.