<div>Reliable water availability is critical to supporting communities and industries such as mining, agriculture and tourism. In remote and arid areas such as in the Officer – Musgrave region of central Australia, groundwater is the only viable source of water for human and environmental use. Groundwater systems in remote regions such as the Musgrave Province are poorly understood due to sparse geoscientific data and few detailed scientific investigations. The Musgrave palaeovalley module will improve palaeovalley groundwater system understanding in the Musgrave Province and adjacent basins to identify potential water sources for communities in the region. This report summarises the state of knowledge for the region on the landscape, population, water use, geology and groundwater systems. An analysis of the current and potential future water needs under different development scenarios captures information on how water is used in an area covering three jurisdictions and several potentially competing land uses.</div><div>The Musgrave Palaeovalley study area is generally flat, low-lying desert country. The Musgrave, Petermann, Mann and Warburton ranges in the centre of the area are a significant change in elevation and surface materials, comprising rocky hills, slopes and mountains with up to 800&nbsp;m of relief above the sand plains. Vegetation is generally bare or sparse, with isolated pockets of grassy or woody shrub lands. Soils are typically Tenosols, Rudosols and Kandosols.</div><div><br></div><div>There are four main hydrogeological systems in the study area. These are the fractured and basement rocks, local Quaternary sediments regional sedimentary basins and palaeovalley aquifers. These systems are likely to be hydraulically connected. Within palaeovalleys, three main hydrostratigraphic units occur. The upper Garford Formation is a sandy unconfined aquifer with a clay rich base (lower Garford Formation) which acts as a partial aquitard where present. The Pidinga Formation represents a coarser sandy or gravelly channel base, which is partly confined by the lower Garford Formation aquitard. The aquifers are likely to be hydraulically connected on a regional scale. Further to the west, equivalent units are identified and named in palaeovalley systems on the Yilgarn Craton. </div><div><br></div><div>Groundwater is recharged by episodic, high-intensity rainfall events and mostly discharges via evapotranspiration. Recharge is higher around the ranges, and lower over the flatter sand plains. Palaeovalley aquifers likely receive some groundwater inflow from underlying basin systems and fractured rock systems. Regional groundwater movement is topographically controlled, moving from the ranges towards surrounding areas of lower elevation. In some palaeovalleys groundwater discharges at playa lakes. Water table gradients are very low. More groundwater isotope and tracer data is required to understand potential connectivity between basin, fractured rock and palaeovalley systems.</div><div>Groundwater quality is brackish to saline, although pockets of fresher groundwater occur close to recharge areas and within the deeper and coarse-grained Garford Formation. Groundwater resources generally require treatment prior to use Most groundwater in the region is suitable for stock use. </div><div><br></div><div>Existing palaeovalley mapping is restricted to inferring extents based on landscape position and mapped surface materials. Utilising higher resolution digital elevation models and more recently acquired remotely sensed data will refine mapped palaeovalley extents. Improving the modelling of the distribution and depth of palaeovalleys in greater detail across the region is best aided through interpretation of airborne electromagnetic (AEM) data.</div><div>Based on the successes of integrating AEM with other geoscientific data in South Australia, we have acquired 25,109 line km of new AEM across the WA and NT parts of our study area. We will integrate this data with reprocessed and inverted publicly available AEM data, existing borehole information, existing and newly acquired hydrochemical data, and new surface magnetic resonance data to model the three dimensional distribution of palaeovalleys in the study area. We will use these models and data as the basis for conceptualising the hydrogeology of the palaeovalley systems, and provide information back to local communities and decision-makers to inform water management decisions. The data will also provide valuable precompetitive information for future economic development in the region.</div><div><br></div>

Magnetotelluric (MT) data allow geoscientists to investigate the link between mineralisation and lithospheric-scale features and processes. In particular, the highly conductive structures imaged by MT data appear to map the pathways of large-scale palaeo-fluid migration, which is an important element of several mineral systems. New data were collected as part of the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) under Geoscience Australia Exploring for the Future (EFTF) program in northern Australian. We use this dataset to demonstrate that the MT method is a valuable tool for mapping lithospheric-scale features and for selecting prospective areas for mineral exploration. Our results image a number of major conductive structures at depths up to ~200 km or deeper in the survey region, for example, the Carpentaria Conductivity Anomaly in east of Mount Isa; and the Tanami Conductive Anomaly along the Willowra Suture Zone. These significant anomalies are lithospheric- scale highly conductive structures, and show spatial correlations with major suture zones and known mineral deposits. These results provide important first-order information for lithospheric architecture and possible large footprint of mineral systems. Large-scale crustal/mantle conductivity anomalies mapping fluid pathways associated with major sutures/faults may have implications for mineral potential. These results provide evidence that some mineralisation occurs at the gradient of or over highly conductive structures at lower crustal and lithospheric mantle depths. These observations provide a powerful means of highlighting greenfields for mineral exploration in under-explored and covered regions.

<div>Poster for the Specialist Group in Geochemistry, Mineralogy & Petrology (SGGMP) conference in Yallingup WA in November 2022.</div><div><br></div>This Poster was presented to the 2022 Specialist Group in Geochemistry, Mineralogy and Petrology (SGGMP) Conference 7-11 November (https://gsasggmp.wixsite.com/home/biennial-conference-2021)

<p>The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) aims to collect long period magnetotelluric data on a half degree (~55 km) grid across the Australian continent. New datasets have been collected in Northern Australia, as part of Geoscience Australia’s Exploring for the Future (EFTF) program with in-kind contributions from the Northern Territory Geological Survey and the Queensland Geological Survey. <p>This release includes preliminary AusLAMP models in an under-explored region between Tennant Creek in the Northern Territory and Cloncurry in Queensland. Long period magnetotelluric data from 155 sites were used in this model. Magnetotelluric data acquisition in this region continues. The preliminary model results provide new insights to the lithospheric architecture and mineralisation in the region. There is a connection between conductive anomalies, large-scale lithospheric boundaries and the distribution of mineral deposits.

<div>This was the last of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop. Towards developing a 3D hydrogeological framework for Australia: A common chronostratigraphic framework for aquifers&nbsp;</div><div><br></div>

<div>Report on expression of interest, assessment and identification process of case studies to be included in the Exploring for the Future Geoscience Knowledge Sharing Project Remote Community Education Module and Building Relationships with Aboriginal Peoples Modules. &nbsp;The Geoscience Knowledge Sharing Project is a pilot study to discover best practices to improve engagement with non-technical stakeholders. </div>

<div>Alkaline igneous and related rocks are recognised as a significant source of the critical minerals essential for Australia’s transition to net-zero. Understanding these small but economically significant group of poorly mapped rocks is essential for identifying their resource potential. The Australian Alkaline Rocks Atlas aims to capture all known occurrences of these volumetrically minor, but important, igneous rocks in a national compilation, to aid understanding of their composition, distribution and age at the continental scale. The Atlas, comprises five, stand-alone data packages covering the Archean, Proterozoic, Paleozoic, Mesozoic and Cenozoic eras. Each data package includes a GIS database and detailed accompanying report that informs alkaline rock nomenclature, classification procedures, individual units and their grouping into alkaline provinces based on common age, characteristics and inferred genesis. The Alkaline Rocks Atlas will form a foundation for more expansive research on related mineral systems and their corresponding economic potential being undertaken as part of the EFTF program. To illustrate the use of the Alkaline Rocks Atlas, a mineral potential assessment using a subset of the Atlas has been undertaken for carbonatite-related rare earth element mineral systems that aims to support mineral exploration and land-use decision making that aims to support mineral exploration and land-use decision making.</div>

<div>A PowerPoint presentation given by Chief of Minerals, Energy and Groundwater Division Dr Andrew Heap at NT Resources Week 2023. </div><div><br></div><div>This presentation had the theme of 'Precompetitive geoscience - Uncovering our critical minerals potential.'</div>

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 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. A comprehensive geochemical program designed to provide information about the region’s resource potential was carried out on samples collected at up to 4 meter intervals. This report presents data from magnetic susceptibility analyses undertaken by Geoscience Australia on selected rock samples to establish their ability to be magnetised in an applied external magnetic field.

Geoscience Australia commissioned reprocessing of selected legacy 2D seismic data in the Officer Basin in South Australia as part of the Exploring for the Future (EFTF) program. Reprocessing of these data occurred between April 2021 and August 2021. This seismic data release package contains reprocessed data from five surveys acquired between 1966 and 1987. In total it contains approximately 1425 km of industry 2D reflection seismic data comprising of 25 lines from 5 separate vintages. The seismic surveys include the Serpentine Lakes Reconnaissance Survey, 1966; the Everard Survey, 1974; the Marla Bore Survey, 1984; the Ungoolya, Giles and Marla-Byilkaoora Surveys, 1985; and the Amoco Officer Basin Survey, 1987 and cover areas within the Officer Basin in South Australia. The objective of the seismic reprocessing was to produce processed 2D land seismic reflection datasets using the latest processing techniques to improve continuity and data quality over legacy processing. In particular, the purpose of the reprocessing was to image the structure and stratigraphic architecture of the Neoproterozoic to Paleozoic Officer Basin in this area. All vintages except the 1966 Serpentine lakes survey were processed to Pre-stack Time Migration as well as Post-Stack Time Migration. The 1966 Serpentine Lakes Survey was processed only to Post-Stack Time Migration. <b>The Velseis data package is available on request from clientservices@ga.gov.au - Quote eCat# 145905</b>