This web service provides access to satellite imagery products for the identification of potential groundwater dependent ecosystems (GDEs) in the South Nicholson - Georgina region.

A key challenge in exploring Australian onshore sedimentary basins is limited seismic data coverage. Consequently, well logs are often the main datasets that can be used to understand the subsurface geology. The primary aim of this study was to develop a methodology for visualising the three-dimensional (3D) tectonostratigraphic architecture of sedimentary basins using well data, which can then be used to quickly screen areas warranting more detailed studies of resource potential. This project has developed a workflow that generates 3D well correlations using sequence stratigraphic well tops to visualise the regional structural and stratigraphic architecture of the Amadeus, Canning, Officer and Georgina basins in the Centralian Superbasin. Thirteen Neoproterozoic‒Paleozoic supersequence tops were interpreted in 134 wells. Three-dimensional well correlations provide an effective regional visualisation of the tectonostratigraphic architecture across the main depocentres. This study redefines the Centralian Superbasin as encompassing all western, northern and central Australian basins that had episodically interconnected depositional systems driven by regional subsidence during one or more regional tectonic events between the Neoproterozoic and middle Carboniferous. The Centralian Superbasin began to form during Neoproterozoic extension, and underwent several phases of partial or complete disconnection and subsequent reconnection of depositional systems during various regional tectonic events before final separation of depocentres at the culmination of the Alice Springs Orogeny. Regional 3D correlation diagrams have been generated to show the spatial distribution of these supersequences, which can be used to visualise the distribution of stratigraphic elements associated with petroleum, mineral and groundwater systems. <b>Citation: </b>Bradshaw, B., Khider, K., MacFarlane, S., Rollet, N., Carr, L. and Henson, P., 2020. Tectonostratigraphic evolution of the Centralian Superbasin (Australia) revealed by three-dimensional well correlations. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

This web service provides access to satellite imagery products for the identification of potential groundwater dependent ecosystems (GDEs) in the South Nicholson - Georgina region.

The Western Davenport region has been identified as an area of interest for future agricultural development. However, realisation of this potential depends on access to a reliable supply of groundwater, underpinned by rigorous geological and groundwater information. A three-dimensional stratigraphic model has been created for the Western Davenport area of the Southern Stuart Corridor project under the Exploring for the Future program. Our interpretation integrates airborne electromagnetic data with historical drillhole and outcrop data to improve geological and hydrogeological understanding. Results show that stratigraphies of the Wiso and Georgina basins are equivalent and laterally continuous in this area. This enables a more complete hydrostratigraphy to be defined and underpins improved hydrogeological conceptualisation. New hydrochemical data support the conceptual model that the aquifers of the Wiso and Georgina basins are interconnected at a regional scale. The initial assessment of water quality indicates that groundwater may support further agricultural development. Analysis of new water chemistry data has improved understanding of groundwater processes and potential areas of recharge. This work will inform management decisions to enhance the economic and social opportunities in the Western Davenport area, while protecting the environmental and cultural value of water resources. <b>Citation:</b> Northey, J.E., Clark, A.D., Smith, M.L. and Hostetler, S., 2020. Delineation of geology and groundwater resources in a frontier region: Western Davenport, Northern Territory. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

Small-angle neutron scattering (SANS) measurements were performed on 32 rock samples from the southern Georgina Basin, central Australia to assess nanopore anisotropy. Anisotropy can only be determined from oriented core material, hence the samples were cut perpendicular to bedding in cores selected from three wells that intersect the base of the hydrocarbon-bearing, organic-rich middle Cambrian Arthur Creek Formation; the latter is the source rock for both unconventional and conventional plays in the basin. The evolution of anisotropy of two-dimensional SANS intensity profiles with depth (for pore diameters ranging from 10 nm to 100 nm) was quantified and correlated with SANS intensity and total organic carbon (TOC) content. Our results confirm hydrocarbon generation at the base of the Arthur Creek Formation. The nanopore anisotropy in the basal Arthur Creek Formation at the well locations CKAD0001 (oil generation window) and MacIntyre 1 (late oil generation window) varies roughly according to normal compaction. When the Arthur Creek Formation is in the gas window, as sampled at Baldwin 1, there is a strong (negative) correlation between the average vertical-to-horizontal pore shape anisotropy and SANS intensity. The results indicate that unconventional gas production from organic-rich regions of over mature shale may be adversely affected by abnormal pore compaction.

Small angle neutron scattering (SANS) and ultra-small angle neutron scattering (USANS) are used to directly detect the processes of hydrocarbon generation in the 10 nm to 10 μm size pores in carbonate and siliciclastic rocks which contain no land-plant material suitable for conventional maturity determination by vitrinite reflectance. The method takes advantage of the pore-size-specific variation of neutron scattering contrast between the solid rock matrix and pore-space content with depth, which is caused by thermal maturation of organic matter through the oil and gas generation windows. SANS and USANS measurements were performed on bedding plane-orientated core slices, extracted from a series of 10 to 12 depth intervals for three wells, CKAD0001, MacIntyre 1 and Baldwin 1 in the southern Georgina Basin, central Australia. The depth intervals, intersecting the organic-rich basal ‘hot’ shales of the middle Cambrian Arthur Creek Formation, were selected based on Rock-Eval pyrolysis data. SANS and USANS results indicate that oil generation has occurred in the past in nano-sized pores in rocks that are now at depths of around 538.4 m in CKAD0001 and 799.3 m in MacIntyre 1. Furthermore, in the CKAD0001 well, the oil-wet pores extend into the larger pore-size range (at least up to 10 μm) due to the efficient expulsion of oil. At around 880 m in Baldwin 1, the influence of pyrobitumen reverts pore space from gas wet to oil wet. These hydrocarbons have remained in situ since the Devonian when the Neoproterozoic to Paleozoic section was exhumed in the Alice Springs Orogeny and subsequently eroded, preserving only remnants of the once extensive basin sediments.

Following the publication of Geoscience Australia record 2014/09: Petroleum geology inventory of Australia's offshore frontier basins by Totterdell et. al, (2014), the onshore petroleum section embarked upon a similar project for onshore Australian basins. The purpose of this project is to provide a thorough basis for whole of basin information to advise the Australia Government and other stakeholders, such as the petroleum industry, regarding the exploration status and prospectivity of onshore Australian basins. Eight onshore Australian basins have been selected for this volume and these include: the McArthur, South Nicholson, Georgina, Amadeus, Warburton, Wiso, Galilee and Cooper basins. This record provides a comprehensive whole of basin inventory of the geology, petroleum systems, exploration status and data coverage for these eight onshore Australian basins. It draws on precompetitive work programs by Geoscience Australia as well as publicly available exploration results and geoscience literature. Furthermore, the record provides an assessment of issues and unanswered questions and recommends future work directions to meet these unknowns.

<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>

This record presents nine new Sensitive High Resolution Ion Micro Probe (SHRIMP) U–Pb zircon results obtained under the auspices of the Exploring for the Future (EFTF) Programme, a four year, federally funded initiative to better understand the mineral, energy and groundwater potential of northern Australia. The results presented here are derived from eight sedimentary samples and one probable tuffaceous sample together belonging to the Mount Isa Province, South Nicholson Basin and Georgina Basin.

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.