Abstract: The extent to which fluids may leak from sedimentary basins to the seabed is a critical issue for assessing the potential of a basin for carbon capture and storage. The Petrel Sub-basin, located beneath central and eastern Joseph Bonaparte Gulf in tropical northern Australia, is identified as potentially suitable for the geological storage of CO2 because of its geological characteristics and proximity to offshore gas and petroleum resources. In May 2012, a multidisciplinary marine survey was undertaken to collect data in two targeted areas of the Petrel Sub-basin to facilitate an assessment of CO2 storage potential. Multibeam bathymetry and backscatter mapping (650 km2 over 5,300 line km), combined with acoustic sub-bottom profiling (650 line km) and geomorphological and sediment characterisation of the seabed was undertaken above the CO2 supercritical seal boundary of the sub-basin. Features identified in the high resolution (2 m) bathymetry data include carbonate banks, ridges, pockmark fields and fields of low amplitude hummocks located directly adjacent to banks. Unit and composite pockmarks and clusters of pockmarks are present on plains and adjacent to, and on, carbonate ridges. It is postulated that there are three possible sources for fluids and fluidised gas involved in pockmark formation: deep fluids from the basin, post-Cretaceous intra-formational, layer-bound fluids, and shallow-sourced fluidised gas from the breakdown of organic matter following the Holocene marine transgression of Joseph Bonaparte Gulf.

Here we present the GIS dataset for the surficial geology map for the Vestfold Hills, East Antarctica. On the coast of Prydz Bay, the region is one of the largest ice-free areas in Antarctica. Surficial geology mapping at 1:2000 was undertaken with field observations in the 2018/19 and 2019/20 summer seasons as well as aerial photography and satellite imagery interpretation. Units are based on the Geological Survey of Canada Surficial Data Model Version 2.4.0 (Deblonde et al 2019). This geodatabase, set of layer files (including sample and field observation sites), and metadata statement complement the flat pdf map published in 2021 - https://pid.geoscience.gov.au/dataset/ga/145535.

Managed aquifer recharge (MAR) enhances recharge to aquifers. As part of the Exploring for the Future Southern Stuart Corridor project, remotely sensed data were used to map regolith materials and landforms, and to identify areas that represent potential MAR target areas for future investigation. Nine areas were identified, predominantly associated with alluvial landforms in low-gradient landscape settings. The surface materials are typically sandy, or sandy and silty, with the prospective areas overlying newly identified groundwater resources associated with Paleozoic sedimentary rocks of the Wiso and Georgina basins. The workflow used here can be rapidly rolled out across broader areas, and can be supplemented by higher-resolution, longer time-series remote-sensing data, coupled with data analytics, modelling and expert knowledge. Such an approach will help to identify areas of the arid interior that may be suitable for MAR schemes that could supplement water for remote communities, and agricultural and other natural resource developments. <b>Citation:</b> Smith, M.L., Hostetler, S. and Northey, J., 2020. Managed aquifer recharge prospectivity mapping in the Northern Territory arid zone using remotely sensed data. 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 flythrough highlights canyon environments within the Gascoyne Marine Park offshore northwestern Australia. The Cape Range Canyon is a relatively narrow, linear canyon that initiates on the continental slope, but is connected to the shelf via a narrow channel. The walls of the canyon are steep and reveal a history of slumping and retrogressive failure, that have broadened the canyon over time. The floor contains a series of deep plunge pools, indicative of the action of sediment-laden turbidity currents in further eroding this canyon. Epibenthos within the canyons was relatively sparse and likely regulated by disturbance associated with sedimentation in the canyons. Rock overhangs often supported the highest densities of benthic suspension feeders, including glass sponges, octocorals, and ascidians. Bathymetry data and seafloor imagery for this flythrough was collected by the Schmidt Ocean Institute during survey FK200308. Funding was provided by Schmidt Ocean Institute, Geoscience Australia, the Australian Government’s National Environmental Science Program (NESP) Marine Biodiversity Hub, the Director of National Parks, and the Foundation for the WA Museum through a Woodside Marine Biodiversity Grant.

<div>A groundwater chemistry, regolith chemistry and metadata record for legacy geochemical studies over the southern Curnamona Province done by GA and partners as part of CRC LEME from 1999 to 2005, that was never fully released. This includes comprehensive groundwater chemistry from more than 250 bores in the Broken Hill region, containing physicochemical parameters, major and trace elements, and a suite of isotopes (34S, Pb, Sr, 18O, D). Recent work on this dataset (in 2021) has added hydrostratigraphic information for these groundwater samples. Also included is a regolith geochemistry dataset collected adjacent to some of the groundwater bores which tests the geochemical response of a range of different size fractions, depths and digests.</div>

Repeat multibeam mapping of two slope-confined canyons on the northwest Australian margin provides new understanding of the processes that are active in shaping these environments. The Cape Range and Cloates Canyons initiate on the mid- to lower continental slope, but are connected to the shelf via small channels and gullies. These canyons were first mapped systematically with multibeam sonar in 2008 and were remapped in 2020 during a biodiversity survey that also collected high-resolution imagery and biological samples from a deep-water Remotely Operated Vehicle. Comparison of features between the two surveys indicates active sliding, minor headwall retreat and continued excavation of deep floor depressions, reflecting the action of high energy turbidity currents. Significantly, intact blades of displaced seagrass imaged throughout both canyons at depths up to 4200 m indicates that sediment sourced from the adjacent continental shelf is being channelled through these canyon systems. Sedimentation likely regulates benthic communities in these canyons, with imagery showing highest densities of sessile invertebrates in habitats protected from sedimentation (e.g. rock overhangs). Repeat mapping provides an understanding of the dynamics of these canyons and a context for assessing and monitoring the stability of the seabed habitats within a marine reserve. <b>Citation:</b> Alexandra L. Post, Rachel Przeslawski, Rachel Nanson, Justy Siwabessy, Deborah Smith, Lisa A. Kirkendale, Nerida G. Wilson, Modern dynamics, morphology and habitats of slope-confined canyons on the northwest Australian margin, <i>Marine Geology</i>, 2022, 106694, ISSN 0025-3227, https://doi.org/10.1016/j.margeo.2021.106694.

The deep waters within the Gascoyne Marine Park have been largely unexplored for their seafloor biodiversity. Survey FK200308 on the RV Falkor targeted two canyons within the Gascoyne Marine Park to understand and map the distribution and diversity of marine habitats and biota within the Cape Range and Cloates Canyons. These canyons were targeted to better understand their ecological significance as a conduit between shelf environments adjacent to the Ningaloo Reef and the abyssal plain. They occur within the habitat protection and multiple use zones of the Gascoyne Marine Park off north-western Australia. Survey FK200308 was led by researchers at the Western Australian Museum, and included scientists from Geoscience Australia, Curtin University, Macquarie University and Scripps Institute of Oceanography. Multibeam sonar was used to map parts of the marine park, while a Remotely Operated Vehicle (ROV) was deployed to undertake a comprehensive taxon inventory of the North-West canyon fauna based on underwater imagery and sampling. Additional biological samples were collected via plankton sampling, as well as fish and crustacean traps on a lander, and stand-alone fish trap deployments. Autonomous Reef Monitoring Structures (ARMS) were deployed at select sites to capture cryptic benthic organisms over several years. DNA samples from the water column (eDNA) were collected to enable a broader understanding of the biodiversity of the region, and to provide a methodological comparison to the organisms present at the time of sampling. The key drivers for this survey were to collect Information to enhance our understanding of the Gascoyne Marine Park and deep-sea environments throughout Western Australia, and to facilitate comparisons between the north-west and eastern and southern Australian deep-sea waters. This information can be applied to inform management plans, scientific research and industry activities for the North-West. Specifically, this survey provided: • A faunal inventory as a baseline information for monitoring deep water WA environments. A total of 2570 seafloor images were annotated from quantitative transects, more than 1000 specimens were collected and up to 30 new species discovered. • High resolution mapping of the seafloor across an area of 11,250 km2 revealed a detailed understanding of seabed habitats and environments in the Gascoyne Marine Park, and a regional context in which to interpret the faunal inventory. • Repeat multibeam mapping of the Cape Range and Cloates Canyons informed our understanding of seabed stability in the canyons of the Gascoyne Marine park, illustrating a rare case of true monitoring using multibeam in Australian waters. • The use of a state-of-the-art ROV across 20 deployments helped inform a new ROV field manual (Monk et al. 2020), adding to the existing suite of standard operating procedures supported by Parks Australia (https://marine-sampling-field-manual.github.io/). This survey confirmed that canyons within the Gascoyne Marine Park are important ecological systems, supporting numerous deep-sea species, many of which were discovered to be new to science. The advanced capabilities of the ROV SuBastian to navigate and image complex near vertical walls and overhangs within the canyons revealed patterns in the distribution of the seafloor taxa consistent with small-scale environmental variability. Repeat multibeam mapping revealed a dynamic canyon system that continues to be shaped by turbidity events. The occurrence of reworked seagrass blades within the canyons provided new understanding of these canyon systems as an active conduit between shallow shelf and abyssal environments. The distribution of the seabed biota revealed through quantitative ROV transects emphasised the importance of disturbance patterns in shaping the canyon ecosystems.

Remotely sensed data and updated DEM and radiometric datasets, combined with existing surface material and landform mapping were used to map regolith landform units for the Ti Tree, Western Davenport and Tennant Creek regions of the SSC project. This report describes the methods used and outlines the new mapping.

Remotely sensed data and updated DEM and radiometric datasets, combined with existing surface material and landform mapping were used to map regolith landform units for the Alice Springs study area of the SSC project. This report describes the methods used and outlines the new mapping.

This report presents key results from hydrogeological investigations in the Tennant Creek region, completed as part of Exploring for the Future (EFTF)—an eight year, $225 million Australian Government funded geoscience data and information acquisition program focused on better understanding the potential mineral, energy and groundwater resources across Australia. The EFTF Southern Stuart Corridor (SSC) Project area is located in the Northern Territory and extends in a north–south corridor from Tennant Creek to Alice Springs, encompassing four water control districts and a number of remote communities. Water allocation planning and agricultural expansion in the SSC is limited by a paucity of data and information regarding the volume and extent of groundwater resources and groundwater systems more generally. Geoscience Australia, in partnership with the Northern Territory Department of Environment and Natural Resources and Power and Water Corporation, undertook an extensive program of hydrogeological investigations in the SSC Project area between 2017 and 2019. Data acquisition included; helicopter airborne electromagnetic (AEM) and magnetic data; water bore drilling; ground-based and downhole geophysical data for mapping water content and defining geological formations; hydrochemistry for characterising groundwater systems; and landscape assessment to identify potential managed aquifer recharge (MAR) targets. This report focuses on the Tennant Creek region—part of the Barkly region of the Northern Territory. Investigations in this region utilised existing geological and geophysical data and information, which were applied in the interpretation and integration of AEM and ground-based geophysical data, as well as existing and newly acquired groundwater hydrochemical and isotope data. The AEM and borehole lithological data reveal the highly weathered (decomposed) nature of the geology, which is reflected in the hydrochemistry. These data offer revised parameters, such as lower bulk electrical conductivity values and increased potential aquifer volumes, for improved modelling of local groundwater systems. In many instances the groundwater is shown to be young and of relatively good quality (salinity generally <1000 mg/L total dissolved solids), with evidence that parts of the system are rapidly recharged by large rainfall events. The exception to this is in the Wiso Basin to the west of Tennant Creek. Here lower quality groundwater occurs extensively in the upper 100 m below ground level, but this may sit above potentially potable groundwater and that possibility should be investigated further. Faults are demonstrated to have significantly influenced the occurrence and distribution of weathered rocks and of groundwater, with implications for groundwater storage and movement. Previously unrecognised faults in the existing borefield areas should be investigated for their potential role in compartmentalising groundwater. Additionally a previously unrecognised sub-basin proximal to Tennant Creek may have potential as a groundwater resource or a target for MAR. This study has improved understanding of the quantity and character of existing groundwater resources in the region and identified a managed aquifer recharge target and potential new groundwater resources. The outcomes of the study support informed water management decisions and improved water security for communities; providing a basis for future economic investment and protection of environmental and cultural values in the Tennant Creek and broader Barkly region. Data and information related to the project are summarised in the conclusions of this report and are accessible via the EFTF portal (https://portal.ga.gov.au/).