Promotional Video designed to highlight the appeal of the Geological TimeWalk and attract visitors to Geoscience Australia, featuring GA Chief Scientist Dr. Steve Hill.

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.

Geoscience Australia’s Exploring for the Future (EFTF) program has established new techniques to collect onshore pre-competitive datasets on an unprecedented scale. The Exploration Incentive Scheme (EIS) is a Western Australian Government initiative that aims to encourage exploration for the long-term sustainability of the state’s resources sector. Integration of EFTF and EIS datasets has improved understanding of the geology across northern Australia, and the associated energy, mineral and groundwater resources potential. The onshore Canning Basin covers approximately 530 000 km2, and has proven prospectivity for conventional oil and gas, mainly in the northern part of the basin. Potential exists for unconventional resources that remain largely unexplored and untested. Gas resource assessments suggest that the basin has significant potential for recoverable shale gas and tight gas. Even with exploration continuing along the flanks of the Fitzroy Trough, the Canning Basin remains one of the least explored Paleozoic basins in the world (DMIRS, 2020). Australia’s longest onshore seismic line, 18GA-KB1, acquired in the southern Canning Basin addresses a long standing data gap across the Kidson Sub-basin and Waukarlycarly Embayment that assists with the resource evaluation of this frontier region. The Kidson Sub-basin covers 91 000 km2 and has a sag basin architecture. Preliminary interpretation of the seismic data indicates that the sedimentary basin is approximately 6 km deep, and includes a conformable package of Ordovician–Devonian siliciclastic, carbonate and evaporite facies of exploration interest. The Carboniferous succession is interpreted as not being present. Located on the western end of the seismic line, the newly drilled deep stratigraphic well Waukarlycarly 1 penetrated 2680.53 m of Cenozoic and Paleozoic strata and provides stratigraphic control for the geology imaged in the Waukarlycarly Embayment. A comprehensive elemental and δ13C isotope chemostratigraphy study assists with stratigraphic correlations within Ordovician sedimentary strata across the region (Forbes et al., 2020a, b). Oil and gas discoveries throughout the Canning Basin were generated from Paleozoic marine source rocks, deposited under stratified oxic and euxinic water columns. Three distinct petroleum systems, the Ordovician (Larapintine 2), Late Devonian (Larapintine 3) and latest Devonian–early Carboniferous (Larapintine 4), are recognized based on the geochemical character of their associated fluids and each display strong stratigraphic control (Carr et al., 2020). Widespread generation of gas from Paleozoic sources is evident from molecular analyses of gases recovered from petroleum wells and fluid inclusions (Boreham et al., 2020). Currently the Larapintine 2 Petroleum System is deemed most prospective system in the Kidson Sub-basin.

Exploring for the Future (EFTF) is an ongoing multiyear initiative by the Australian Government, conducted by Geoscience Australia, in partnership with state and Northern Territory government agencies and other partner research institutes. The first phase of the EFTF program (2016-2020) aimed to improve Australia’s desirability for industry investment in resource exploration in frontier or ‘greenfield’ regions across northern Australia. As part of the program, Geoscience Australia employed a range of both established and innovative techniques to gather new precompetitive data and information to develop new insight into the energy, mineral and groundwater resource potential across northern Australia. To maximise impact and to stimulate industry exploration activity, Geoscience Australia focussed activities in greenfield areas where understanding of resource potential was limited. In order to address this overarching objective under the EFTF program, Geoscience Australia led acquisition of two deep crustal reflection seismic surveys in the South Nicholson region, an understudied area of little previous seismic data, straddling north-eastern Northern Territory and north-western Queensland. The first survey, L210 South Nicholson 2D Deep Crustal Seismic Survey acquired in 2017, consisted of five overlapping seismic lines (17GA-SN1 to SN5), totalling ~1100 line-km. Survey L210 linked directly into legacy Geoscience Australia seismic lines (06GA-M1 and 06GA-M2) in the vicinity of the world-class Pb-Zn Century Mine in Queensland. The results from survey L210 profoundly revised our geological understanding of the South Nicholson region, and led to the key discovery of an extensive sag basin, the Carrara Sub-basin, containing highly prospective late Paleoproterozoic to Mesoproterozoic rocks with strong affinities with the adjacent Mount Isa Province and Lawn Hill Platform. To complement and expand on the outstanding success of the South Nicholson survey and to continue to explore the resource potential across the underexplored and mostly undercover South Nicholson and Barkly regions, a second seismic survey was acquired in late 2019, the Barkly 2D reflection survey (L212). The Barkly seismic survey comprises five intersecting lines (19GA-B1 to B5), totalling ~813 line-km, extending from the NT-QLD border in the south-east, near Camooweal, to the highly prospective Beetaloo Sub-basin in the north-west. The survey ties into the South Nicholson survey (L210), the recently acquired Camooweal 2D reflection seismic survey by the Geological Survey of Queensland and industry 2D seismic in the Beetaloo Sub-basin, leveraging on and maximising the scientific value and impact on all surveys. The Barkly reflection seismic data images the south-western margin of the Carrara Sub-basin and identified additional previously unrecognised, structurally-disrupted basins of Proterozoic strata, bounded by broadly northeast trending basement highs. Critically, the survey demonstrates the stratigraphic continuity of highly prospective Proterozoic strata from the Beetaloo Sub-basin into these newly discovered, but as yet unevaluated, concealed basins and into the Carrara Sub-basin, further attesting to the regions outstanding potential for mineral and hydrocarbon resources. This survey, in concert with the South Nicholson seismic survey and other complementary EFTF funded regional geochemical, geochronology and geophysical data acquisition surveys, significantly improves our understanding of the geological evolution, basin architecture and the resource potential of this previously sparsely studied region.

<p>This is a raster representing the base surface of the Nulla Basalt Province, inferred from sparse data available, dominated by private water bore records. This interpretation was conducted by a hydrogeologist from Geoscience Australia. <p>Caveats <p>• This is just one model, based on sparse data and considerable palaeotopographic interpretation <p>• This model relies on the input datasets being accurate. However it is noted that substantial uncertainty exists both in the location of private bores and the use of drillers’ logs for identifying stratigraphic contacts. <p>• The location of palaeothalwegs is imprecise, and often it is only indicative of the presence of a palaeovalley. <p>• The purpose of this model is for visualisation purposes, so should not be considered a definitive depth prediction dataset.

This is a raster representing the base surface of the McBride Basalt Province, inferred from sparse data available, dominated by private water bore records. This interpretation was conducted by a hydrogeologist from Geoscience Australia. Caveats • This is just one model, based on sparse data and considerable palaeotopographic interpretation • This model relies on the input datasets being accurate. However it is noted that substantial uncertainty exists both in the location of private bores and the use of drillers’ logs for identifying stratigraphic contacts. • The location of palaeothalwegs is imprecise, and often it is only indicative of the presence of a palaeovalley. • The purpose of this model is for visualisation purposes, so should not be considered a definitive depth prediction dataset.

<p>The outcrop extent of the McBride Basalt Province, selected from the Queensland Detailed Surface Geology vector polygon mapping, March 2017. <p>© State of Queensland (Department of Natural Resources and Mines) 2017 Creative Commons Attribution

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.

As part of the Onshore Energy Systems Group’s program, late gas (methane) and compositional kinetics (1-, 2-, 4- and 14-component (phase) kinetics) were undertaken by GeoS4, Germany. The phase kinetics approach is outlined in Appendix 1. This report provides the data required to access the shale gas potential of source rocks from the Georgina Basin, Australia.

Exploring for the Future (EFTF) is an ongoing multiyear (2016–2024) initiative of the Australian Government, conducted by Geoscience Australia. This program aims to improve Australia’s desirability for industry investment in resource exploration of frontier regions across Australia. This paper will focus on the science impacts delivered in central northern Australia, by the acquisition and interpretation of seismic surveys, petroleum geochemistry and the drilling of the NDI Carrara 1. This work has been undertaken in collaboration with the Northern Territory Geological Survey, the Queensland Geological Survey, AuScope and the MinEx CRC. The new data acquired across central northern Australia as part of the Exploring for the Future program are foundational datasets and includes seismic surveys, geochronology and geochemistry. These data link the highly prospective resource rich areas of the McArthur Basin and Mt Isa Province via a continuous seismic traverse across central northern Australia. The Exploring for the Future program aims to further de-risk exploration within greenfield regions and position northern Australia for future exploration investment. This presentation was given at the 2023 Australasian Exploration Geoscience Conference (AEGC) 13-18 March, Brisbane (https://2023.aegc.com.au/)