This report is the second of three reports that provide the scientific analyses and interpretations resulting from a four-year collaborative habitat mapping program undertaken within the Darwin and Bynoe Harbour region by Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and the Northern Territory Government Department of Environment and Natural Resources (DENR). This program was made possible through offset funds provided by the INPEX-operated Ichthys LNG Project to DENR, and co-investments from GA and AIMS.

This Record presents 40Ar/39Ar chronologic results acquired in support of collaborative regional geoscientific investigations and mapping programs conducted by Geoscience Australia (GA) and the Northern Territory Geological Survey (NTGS). Argon isotopic data and interpretations from hornblende, muscovite, and biotite from seven samples collected from the Aileron Province in ALCOOTA , HUCKITTA, HALE RIVER, and ILLOGWA CREEK in the Northern Territory are presented herein. The results complement pre-existing geochronological constraints from U–Pb zircon and monazite analyses of the same or related samples, and provide new constraints on the thermal and deformation history of the Aileron Province. Three samples (2003082017, 2003082021, 2003083040) were taken from ALCOOTA in the northeastern portion of the Aileron Province. Biotite in sample 2003082017 from the ca 1.81 Ga Crooked Hole Granite records cooling below 320–280°C at 441 ± 5 Ma. Biotite in sample 2003082021 from the ca 1.73 Ga Jamaica Granite records cooling below 320–280°C at or after 414 ± 2 Ma. Muscovite in sample 2003083040 from the Delny Metamorphics, which were deposited after ca 1.82 Ga and preserve evidence for metamorphism at ca 1.72 Ga and 1.69 Ga, records cooling below 430–390°C at 399 ± 2 Ma. The fabrics preserved in the samples from the Crooked Hole Granite and Delny Metamorphics are interpreted to have formed due to dynamic metamorphism related to movement on the Waite River Shear Zone, an extension of the Delny Shear Zone, during the Palaeoproterozoic. Portions of the northeastern Aileron Province are unconformably overlain by the Neoproterozoic–Cambrian Georgina Basin, indicating these samples were likely at or near the surface by the Neoproterozoic. Together, these data indicate that rocks of the Aileron Province in ALCOOTA were subjected to heating above ~400°C during the Palaeozoic. Two samples (2003087859K, 2003087862F) of exoskarn from an indeterminate unit were taken from drillhole MDDH4 in the Molyhil tungsten–molybdenum deposit in central HUCKITTA. The rocks hosting the Molyhil tungsten–molybdenum deposit are interpreted as ca 1.79 Ga Deep Bore Metamorphics and ca 1.80 Ga Yam Gneiss. They experienced long-lived metamorphism during the Palaeoproterozoic, with supersolidus metamorphism observed until at least ca 1.72 Ga. Hornblende from sample 2003087859K indicates cooling below 520–480°C by 1702 ± 5 Ma and may closely approximate timing of skarn-related mineralisation at the Molyhil deposit; hornblende from sample 2003087862F records a phase of fluid flow at the Molyhil deposit at 1660 ± 4 Ma. The Salthole Gneiss has a granitic protolith that was emplaced at ca 1.79 Ga, and experienced alteration at ca 1.77 Ga. Muscovite from sample 2010080001 of Salthole Gneiss from the Illogwa Shear Zone in ILLOGWA CREEK records cooling of the sample below ~430–390°C at 327 ± 2 Ma. This may reflect the timing of movement of, or fluid flux along, the Illogwa Shear Zone. An unnamed quartzite in the Casey Inlier in HALE RIVER has a zircon U–Pb maximum depositional age of ca 1.24 Ga. Muscovite from sample HA05IRS071 of this unnamed quartzite yields an age of 1072 ± 8 Ma, which likely approximates, or closely post-dates, the timing of deformation in this sample; it provides the first direct evidence for a Mesoproterozoic episode of deformation in this part of the Aileron Province.

<p>The Northern Territory Geological Survey (NTGS) designed the Mount Peake-Crawford survey to provide high resolution magnetic, radiometric and elevation data in the area. It is anticipated that the data from the survey would help attract explorers into ‘greenfield’ terranes and contribute to the discovery of the next generation of major mineral and energy deposits in the Northern Territory. A total of 120,000 line km of regional data (200m line spacing) and additional infill data (100m line spacing), flown at 60m flight height were acquired during the survey between July and October 2019. The survey was managed by Geoscience Australia. <p>Various grids were produced from the Mount Peake-Crawford Airborne Magnetic and Radiometric Survey dataset and simultaneously merged into a single grid file. The final grid retains all of the information from the input data and is levelled to the national map compilations produced by Geoscience Australia. The merged grids have a cell size of 20m. <p>The following merged grids are available in this download: <p>• Laser-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Radar-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Total magnetic intensity grid (nT). <p>• Total magnetic intensity grid with variable reduction to the pole applied (nT). <p>• Total magnetic intensity grid with variable reduction to the pole and first vertical derivative applied (nT/m). <p>• NASVD-filtered potassium concentration grid (%). <p>• NASVD-filtered thorium concentration grid (ppm). <p>• NASVD-filtered uranium concentration grid (ppm).

<div>This data package provides depth and isochore maps generated in support of the energy resource assessments under the Australia’s Future Energy Resources (AFER) project. Explanatory notes are also included.</div><div><br></div><div>The AFER project is part of Geoscience Australia’s Exploring for the Future (EFTF) Program—an eight year, $225 million Australian Government funded geoscience data and precompetitive information acquisition program 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, Geoscience Australia is building a national picture of Australia’s geology and resource potential. This will help support a strong economy, resilient society and sustainable environment for the benefit of all Australians. The EFTF program is supporting Australia’s transition to a low emissions economy, industry and agriculture sectors, as well as economic opportunities and social benefits for Australia’s regional and remote communities. Further details are available at http://www.ga.gov.au/eftf.</div><div><br></div><div>The depth and isochore maps are products of depth conversion and spatial mapping seismic interpretations by Szczepaniak et al. (2023) and Bradshaw et al. (2023) which interpreted 15 regional surfaces. These surfaces represent the top of play intervals being assessed for their energy resource potential (Figure 1). These seismic datasets were completed by play interval well tops by Bradshaw et al. (in prep), gross depositional environment maps, zero edge maps by Bradshaw et al. (in prep), geological outcrop data as well as additional borehole data from Geoscience Australia’s stratigraphic units database.</div><div><br></div><div>Depth and isochore mapping were undertaken in two to interactive phases; </div><div><br></div><div>1.&nbsp;&nbsp;&nbsp;&nbsp;A Model Framework Construction Phase – In this initial phase, the seismic interpretation was depth converted and then gridded with other regional datasets. </div><div><br></div><div>2.&nbsp;&nbsp;&nbsp;&nbsp;A Model Refinement and QC Phase – This phase focused on refining the model and ensuring quality control. Isochores were generated from the depth maps created in the previous phase. Smoothing and trend modelling techniques were then applied to the isochore to provide additional geological control data in areas with limited information and to remove erroneous gridding artefacts.&nbsp;</div><div><br></div><div>The final depth maps were derived from isochores, constructing surfaces both upward and downward from the CU10_Cadna-owie surface, identified as the most data-constrained surface within the project area. This process, utilizing isochores for depth map generation, honours all the available well and zero edge data while also conforming to the original seismic interpretation.</div><div><br></div><div>This data package includes the following datasets: </div><div><br></div><div>1)&nbsp;&nbsp;&nbsp;Depth maps, grids and point datasets measured in meters below Australian Height Datum (AHD, for 15 regional surfaces (Appendix A). </div><div>2)&nbsp;&nbsp;&nbsp;Isochore maps, grids and point datasets measured in meters, representing 14 surfaces/play internals (Appendix B).</div><div>&nbsp;</div><div>These depth and isochore maps are being used to support the AFER Project’s play-based energy resource assessments in the Pedirka and western Eromanga basins, and will help to support future updates of 3D geological and hydrogeological models for the Great Artesian Basin by Geoscience Australia.</div><div><br></div>

<div>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.</div><div><br></div><div>As part of the program, Geoscience Australia (GA) provides a range of established techniques to capture precompetitive geoscience data across underexplored regions to stimulate industry investment in frontier regions of Australia. 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. Furthermore, much of the age of the stratigraphy of the Birrindudu Basin, particularly the younger stratigraphic units, and regional correlations to the greater McArthur Basin remains provisional and speculative. Interpretation of industry seismic data indicates that Proterozoic strata in the western Beetaloo Sub-basin and eastern Birrindudu Basin are continuous in sub-surface.&nbsp;&nbsp;&nbsp;</div><div><br></div><div>In order to provide an improved understanding of the stratigraphy, basin architecture and resource potential of the Birrindudu Basin and surrounding region, GA, in collaboration with the Northern Territory Geological Survey, is acquiring geophysical, geochronological, isotopic, geochemical and geomechanical data as part of phase two of EFTF. The data and results will be released, as they are available, through GA’s eCat Product Catalogue.</div><div><br></div><div>This report presents SHRIMP U-Pb zircon geochronology results on a single igneous sample taken from exploration drillhole LBD2, located in the Birrindudu Basin, intersecting both Paleoproterozoic Limbunya Group and underlying low-grade basement metamorphic rocks.</div>

<div>Groundwater dependent ecosystems (GDEs) rely on access to groundwater on a permanent or intermittent basis to meet some or all of their water requirements (Richardson et al., 2011). The <a href="https://explorer-aws.dea.ga.gov.au/products/ga_ls_tc_pc_cyear_3">Tasseled Cap percentile products</a> created by Digital Earth Australia (2023) were used to identify potential GDEs for the South Nicholson-Georgina basins study area. These percentile products provide statistical summaries (10th, 50th, 90th percentiles) of landscape brightness, greenness and wetness in imagery acquired between 1987 and present day. The 10th percentile greenness and wetness represent the lowest 10% of values for the time period evaluated, e.g. 10th percentile greenness represents the least green period. In arid regions, areas that are depicted as persistently green and/or wet at the 10th percentile have the greatest potential to be GDEs. For this reason, and due to accessibility of the data, the 10th percentile Tasseled Cap greenness (TCG) and Tasseled Cap wetness (TCW) products were used as the basis for the assessment of GDEs for the South Nicholson-Georgina region. The 50th percentile greenness was utilised to create the coefficient of variance (CV) dataset. This data release is an ESRI geodatabase, with layer files, including: - combined classified 10th percentile greenness and wetness dataset (useful to identify potential groundwater dependent vegetation/other GDEs and differentiate between vegetation types) - CV of 50th percentile greenness dataset (useful when used in conjunction with the combined product to help identify groundwater dependent vegetation) For more information and detail on these products, refer to associated <a href="https://dx.doi.org/10.26186/149377">report</a>. </div><div><br></div><div><strong>References</strong></div><div>Digital Earth Australia (2023).&nbsp;<em><a href="https://docs.dea.ga.gov.au/">Digital Earth Australia User Guide.</a></em></div><div>Richardson, S., E. Irvine, R. Froend, P. Boon, S. Barber, and B. Bonneville. 2011a.&nbsp;<em>Australian groundwater-dependent ecosystem toolbox part 1: Assessment framework.</em>&nbsp;Waterlines Report 69. Canberra, Australia: Waterlines.</div><div><br></div>

<div>This study aims to understand both the burial and thermal history of the Carrara Sub-basin to further develop an understanding of possible geo-energy resources, particularly that for unconventional resources such as shale gas. A 1D and 2D model were developed using data from the above mentioned seismic and drilling campaigns, combined with previously published knowledge of the basin. This work contributes to Australia’s Future Energy Resources (AFER) Project, specifically the Onshore Basin Inventories study, which aims to promote exploration and investment in selected underexplored onshore basins. Inventory reports and petroleum systems modelling are being undertaken in select basins to highlight the oil and gas potential in underexplored provinces and to increase the impact of existing datasets.</div><div><br></div>

<div>This data package is a key output from the integrated, basin-scale hydrogeological assessment of South Nicholson-Georgina as part of Geoscience Australia’s National Groundwater Systems project in the Exploring for the Future program.&nbsp;This comprehensive desktop study has integrated numerous geoscience and hydrogeological datasets to develop a new whole-of-basin conceptualisation of groundwater flow systems and recharge and discharge processes within the regional unconfined aquifers of the Georgina Basin.</div><div><br></div><div>This data release includes an ESRI geodatabase and ESRI shapefiles with associated layer files:</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Georgina Basin watertable trend surface</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Georgina Basin reduced standing water level (RSWL) contours</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Regional scale groundwater divides</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Groundwater flow paths</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Bores with aquifer attribution and water level information where available</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Hydrochemistry data for bores and springs, and aquifer attribution (where available)</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Basin boundary extents</div><div><br></div><div>For more information and detail on these products, refer to associated report, Dixon-Jain et al. (2024).</div><div><br></div><div>Dixon-Jain, P., Bishop, C., Lester, J., Orlov, C., McPherson, A., Pho, G., Flower, C., Kilgour, P., Lawson, S., Vizy, J., Lewis, S. 2024. Hydrogeology and groundwater systems of the South Nicholson and Georgina basins, Northern Territory and Queensland. Record 2024/37. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/149730</div>

<div>This Record presents data collected as part of the ongoing Northern Territory Geological Survey–Geoscience Australia SHRIMP geochronology project under the National Collaboration Framework agreement. New U-Pb SHRIMP zircon geochronological results were derived from six samples of sedimentary rocks collected from two petroleum exploration drillholes (CBM 107-001 and CBM 107-002) that intersect the Pedirka Basin in the southeastern corner of the Northern Territory.</div><div><br></div><div>Geologically, this is a region in the Simpson Desert that encompasses several superimposed intracratonic sedimentary basins, which are separated by regional unconformities extending over areas of adjoining Queensland, South Australia and New South Wales. In the southeastern corner of the Northern Territory, the Pedirka Basin is one of three stacked basins. The exposed Mesozoic Eromanga Basin overlies the late Palaeozoic to Triassic Pedirka Basin, which is largely restricted to the subsurface, and in turn overlies the Palaeozoic pericratonic Warburton Basin (Munson and Ahmad 2013).</div><div><br></div><div>As the Pedirka Basin is almost entirely concealed beneath the Eromanga Basin, our current understanding of the geology in this southeastern corner of the Northern Territory is constrained by a limited number of exploration drillholes and 2D seismic coverage (Doig 2022). The samples described herein were collected to aid in defining the chronostratigraphy and sedimentary provenance characteristics of the Pedirka Basin.</div><div><br></div><div>BIBLIOGRAPHIC REFERENCE: Jones S.L., Jarrett A.J., Verdel C.S. and Bodorkos S. 2024. Summary of results. Joint NTGS–GA geochronology project: Pedirka Basin. Northern Territory Geological Survey, Record 2024-003.</div>

<div>NDI Carrara 1 is a 1750 m stratigraphic drill hole completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI) in collaboration with Geoscience Australia under the Exploring for the Future program and the Northern Territory Geological Survey. It is the first stratigraphic test of the Carrara Sub-basin, a recently discovered depocentre in the South Nicholson region. The drill hole intersected Cambrian and Proterozoic sediments consisting of organic-rich black shales and a thick sequence of interbedded black shales and silty sandstones with hydrocarbon shows. A comprehensive analytical program carried out by Geoscience Australia on the recovered core samples from 283 m to total depth at 1751&nbsp;m provides critical data for calibration of burial and thermal history modelling.</div><div>Using data from this drilling campaign, burial and thermal history modelling was undertaken to provide an estimate of the time-temperature maxima that the sub-basin has experienced, contributing to an understanding of hydrocarbon maturity. Proxy kerogen kinetics are assessed to estimate the petroleum prospectivity of the sub-basin and attempt to understand the timing and nature of hydrocarbon generation. Combined, these newly modelled data provide insights into the resource potential of this frontier Proterozoic hydrocarbon province, delivering foundational data to support explorers across the eastern Northern Territory and northwest Queensland.</div> <b>Citation:</b> Palu Tehani J., Grosjean Emmanuelle, Wang Liuqi, Boreham Christopher J., Bailey Adam H. E. (2023) Thermal history of the Carrara Sub-basin: insights from modelling of the NDI Carrara 1 drill hole. <i>The APPEA Journal</i><b> 63</b>, S263-S268. https://doi.org/10.1071/AJ22048