AndreaBozzo/ceres-open-data-index huggingface dataset:
Timing and significance of pre-Olarian metamorphism in the Willyama Supergroup, Broken Hill, Australia

In the Willyama Supergroup of the Curnamona Province, the intensity of granulite facies Olarian metamorphism at c. 1600 Ma has long hampered efforts to elucidate the timing and nature of preceding lower-grade metamorphic events. Previous dating of pre-peak monazite inclusions in aluminous metapelites has been complicated by potentially incomplete isotopic "shielding" by their host porphyroblasts, owing to pervasive deformation and recrystallisation of these rock types during the subsequent c. 1600 Ma event. Near the Broken Hill Pb-Zn orebody, quartz-feldspar-biotite-garnet "Potosi-type" gneiss proved more resistant to granulite facies metamorphism: new Sensitive High Resolution Ion Micro Probe (SHRIMP) U-Pb analyses of monazite delineated a population of relatively Y-rich (median 0.96 wt%) cores at 1636.8 ± 4.4 Ma (95% confidence), which are overprinted by Y-poor (median 0.10 wt%) rims and domains at 1597.3 ± 3.3 Ma. The role of garnet as a sink for Y in metamorphic rocks suggests that Y-rich c. 1637 Ma monazite growth predated garnet formation, and possibly occurred at relatively low metamorphic grade; conversely, the Y-poor nature of the c. 1597 Ma rims and domains indicates that monazite dissolution and reprecipitation during Olarian metamorphism postdated porphyroblastic garnet growth. Coexisting low-Th/U metamorphic zircon rims are dominated by a population at 1600.7 ± 3.6 Ma, emphasising that the event responsible for c. 1637 Ma monazite growth was largely invisible to zircon. A concordant mafic granulite body 70 m away yielded partially recrystallised zircons which feature dark-CL internal domains with elevated U and Th/U, which establish a minimum age of 1639 ± 8 Ma for magmatic crystallisation of the igneous precursor. Recrystallisation was accompanied by actinide depletion, with bright-CL, U-poor and low-Th/U domains dated at 1596 ± 8 Ma. This pair of 1640–1635 Ma dates constitutes robust isotopic evidence for pre-Olarian mafic magmatism and metamorphism within the lower Willyama Supergroup. We infer an extensional environment in the upper mid-crust for this tectonothermal activity, coeval with ongoing sedimentation and deposition of the upper Paragon Group at the surface. Extension of the eastern Curnamona Province at c. 1640 Ma is coeval with sediment-hosted base-metal mineralisation in the Mount Isa Inlier and the McArthur Basin, and is consistent with tectonic regimes prevailing throughout Proterozoic northeastern Australia at that time.
Citation: S. Bodorkos, J.A. Fitzherbert, Timing and significance of pre-Olarian metamorphism in the Willyama Supergroup, Broken Hill, Australia, Precambrian Research, Volume 378, 2022, 106772, ISSN 0301-9268, https://doi.org/10.1016/j.precamres.2022.106772.

Tags: Broken Hill, Curnamona Province, Geochronology, Igneous and Metamorphic Petrology, Isotope Geochemistry, Lady Louise suite, Published_External, SHRIMP, Thackaringa group, U-Pb dating, mafic granulite, monazite, polymetamorphism, potosi-type gneiss, zircon
Organization: Geoscience Australia Data
Paleoseismology of the 2016 MW 6.1 Petermann earthquake source: Implications for intraplate earthquake behaviour and the geomorphic longevity of bedrock fault scarps in a low strain-rate cratonic region

The 20 May 2016 MW 6.1 Petermann earthquake in central Australia generated a 21 km surface rupture with 0.1 to 1 m vertical displacements across a low-relief landscape. No paleo-scarps or potentially analogous topographic features are evident in pre-earthquake Worldview-1 and Worldview-2 satellite data. Two excavations across the surface rupture expose near-surface fault geometry and mixed aeolian-sheetwash sediment faulted only in the 2016 earthquake. A 10.6 ± 0.4 ka optically stimulated luminescence (OSL) age of sheetwash sediment provides a minimum estimate for the period of quiescence prior to 2016 rupture. Seven cosmogenic beryllium-10 (10Be) bedrock erosion rates are derived for samples &lt; 5 km distance from the surface rupture on the hanging-wall and foot-wall, and three from samples 19 to 50 km from the surface rupture. No distinction is found between fault proximal rates (1.3 ± 0.1 to 2.6 ± 0.2 m Myr−1) and distal samples (1.4 ± 0.1 to 2.3 ± 0.2 m Myr−1). The thickness of rock fragments (2–5 cm) coseismically displaced in the Petermann earthquake perturbs the steady-state bedrock erosion rate by only 1 to 3%, less than the erosion rate uncertainty estimated for each sample (7–12%). Using 10Be erosion rates and scarp height measurements we estimate approximately 0.5 to 1 Myr of differential erosion is required to return to pre-earthquake topography. By inference any pre-2016 fault-related topography likely required a similar time for removal. We conclude that the Petermann earthquake was the first on this fault in the last ca. 0.5–1 Myr. Extrapolating single nuclide erosion rates across this timescale introduces large uncertainties, and we cannot resolve whether 2016 represents the first ever surface rupture on this fault, or a &gt; 1 Myr interseismic period. Either option reinforces the importance of including distributed earthquake sources in fault displacement and seismic hazard analyses.
Citation: King, T. R., Quigley, M., Clark, D., Zondervan, A., May, J.-H., &amp; Alimanovic, A. (2021). Paleoseismology of the 2016 M-W 6.1 Petermann earthquake source: Implications for intraplate earthquake behaviour and the geomorphic longevity of bedrock fault scarps in a low strain-rate cratonic region. Earth Surface Processes and Landforms, 46(7), 1238–1256.

Tags: EARTH SCIENCES, Natural Hazards, Published_External, earthquake hazard
Organization: Geoscience Australia Data
Zircon O and Lu-Hf isotopes in Tasmanian Devonian Granites

The Tasmanian Devonian granites were emplaced during the Tabberabberan Orogeny when the East and West Tasmania Terranes collided. The primary aim of this study is to determine zircon O and Lu-Hf isotope constraints on, and relationships between, the magmas forming these granites. A second aim is to determine if these zircon isotopic compositions can be used to inform granite-related ore endowment. Several granites (n = 11 in East Tasmania Terrane, n = 1 West Tasmania Terrane) were previously dated by U-Pb geochronology using SHRIMP, and the zircon pits from the dating analyses were targeted firstly in O and later in Lu-Hf isotope analyses. The magmatic zircon δ18OVSMOW results ranged from mantle-like values (&lt;5.7‰) to values like supracrustal rocks (~12‰). The zircon δ18O results for Tombstone Creek, Lisle and Mt Stronach granites are similar and the most mantle-like. The Tombstone Creek zircon εHfi results are significantly lower than those of Lisle and Mt Stronach, indicating distinct mantle-derived melt sources from which the zircons crystallized. The magmatic zircon δ18O and εHfi results revealed two distinct paths of infracrustal to upper crustal rock εHfi– δ18O melt evolution: one “high εHf” path linking the results from the Lisle, Mt Stronach, Hazards, Henbury, Lottah, Gipps Creek and Royal George granites, and the other “low εHf” path linking those from Tombstone Creek, Meredith, Poimena, Bicheno and Ansons Bay granites. The paths are statistically different and modeled results are consistent with mixing of Mathinna Supergroup rocks with different infracrustal/mantle-like components. The latter components may be different isotopically defined mantle domains or different mixtures of lower crust and mantle. The high εHf group of granites are strongly associated with granite-related Au, Sn, and Sn–W ore deposits.
Citation: Colin L. Jones, Evan A. Orovan, Sebastien Meffre, Jay Thompson, Elena A. Belousova, Matthew J. Cracknell, John Everard, Ralph Bottrill, Simon Bodorkos, David R. Cooke, Zircon O and Lu-Hf isotope evidence of mantle and supracrustal origins of Tasmanian Devonian granites, Gondwana Research, Volume 110, 2022, Pages 1-12, ISSN 1342-937X, ttps://doi.org/10.1016/j.gr.2022.06.004.

Tags: EARTH SCIENCES, Hf-isotope, O-isotope, Tasmania, devonian, granite, melt evolution, mineralization, zircon
Organization: Geoscience Australia Data
Developing synthetic aperture radar (SAR) data for Antarctica Capability development and application

The Sentinel-1 radar satellite provides crucial data for studying environmental change across Australia and Antarctica. Researchers use this data to monitor floods, vegetation, snow and ice, and even land movement. Collaborators at the University of Tasmania have been using the data to develop automated methods to track fast ice year-round. Antarctic fast ice is a key part of the climate system that has declined sharply in recent years and is also a critical habitat for a range of species.
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The lack of standardised, analysis-ready formats until now has limited wider use of satellite radar datasets. Geoscience Australia’s Digital Earth program is filling this gap by producing and sharing high-quality normalised radar backscatter products. The program, including the new Digital Earth Antarctica initiative, is processing huge volumes of radar data, covering more than a decade of observations, so it can be easily and freely used by scientists and decision-makers.

Tags: EARTH SCIENCES, Outreach, Wednesday Seminar, remote sensing
Organization: Geoscience Australia Data
National 3D geological and hydrogeological framework − Groundwater systems, energy and minerals

Geoscience Australia has developed a national-scale 3D model of the country's major geological packages to enhance the understanding of Australia’s groundwater systems. This project, driven by Strategy 2028, as part of the Exploring for the Future program and the Resourcing Australia’s Prosperity initiative, enables scientists to analyse the connections between underground water sources, rock layers, and other natural resources.
By integrating key geological and groundwater data into a unified framework, the model improves how we study and assist in managing water resources across Australia. It also helps update public databases, ensures data consistency, and refines assessment methods for multidisciplinary projects continent-wide. The model reveals potential links between geological units, aquifers, and their interactions with natural resources, guiding future decisions by government, industry, and communities on water use, environmental policies, and resource exploration. Most importantly, it will help ensure Australia has sustainable water supplies for the future.

Tags: Aboriginal and Torres Strait Islander earth sciences, Australia's 3D Groundwater Systems, Australia's 3D geological model, Australia's National Datasets, Groundwater hydrology, National 3D Groundwater Systems Mapping, Published_External, Stratigraphy (incl. biostratigraphy, sequence stratigraphy and basin analysis)
Organization: Geoscience Australia Data
Modeling geomagnetic induction hazards using a 3-D electrical conductivity model of Australia

The surface electric field induced by external geomagnetic source fields is modeled for a continental-scale 3-D electrical conductivity model of Australia at periods of a few minutes to a few hours. The amplitude and orientation of the induced electric field at periods of 360 s and 1800 s are presented and compared to those derived from a simplified ocean-continent (OC) electrical conductivity model. It is found that the induced electric field in the Australian region is distorted by the heterogeneous continental electrical conductivity structures and surrounding oceans. On the northern coastlines, the induced electric field is decreased relative to the simple OC model due to a reduced conductivity contrast between the seas and the enhanced conductivity structures inland. In central Australia, the induced electric field is less distorted with respect to the OC model as the location is remote from the oceans, but inland crustal high-conductivity anomalies are the major source of distortion of the induced electric field. In the west of the continent, the lower conductivity of the Western Australia Craton increases the conductivity contrast between the deeper oceans and land and significantly enhances the induced electric field. Generally, the induced electric field in southern Australia, south of latitude −20°, is higher compared to northern Australia. This paper provides a regional indicator of geomagnetic induction hazards across Australia.
Citation: Wang, L., A. M. Lewis, Y. Ogawa, W. V. Jones, and M. T. Costelloe (2016), Modeling geomagnetic induction hazards using a 3-D electrical conductivity model of Australia, Space Weather, 14, 1125–1135, doi:10.1002/2016SW001436

Tags: 3D Model, EARTH SCIENCES, Published_External, electrical conductivity model, geomagnetic induction hazards, induced electrical fields
Organization: Geoscience Australia Data
A Case Study of Measurement Uncertainty in Field Spectroscopy

In this article, a novel approach to measuring in situ field uncertainties in surface reflectance is presented. This work is an outcome of a national campaign by Geoscience Australia to validate our analysis-ready Landsat 8 and Sentinel 2 surface reflectance products. Various aspects of the field site methodology that were expected to contribute significantly to uncertainties were identified and tested. These aspects included the instrumental uncertainty, the use of a rest to stabilize the spectroradiometer fore-optic, the repositioning of the panel used for calibrating reflectance, and uncertainties introduced by the operator of the equipment, following a standard methodology. Results for two field sites are presented, which consistently show that approximately 95% of the overall uncertainty is a result of inherent variability in the ground surface reflectance. Typically, 5% of the uncertainty is introduced by a combination of the instrumentation and methodology.
Citation: A. J. Walsh, G. Byrne and M. Broomhall, "A Case Study of Measurement Uncertainty in Field Spectroscopy," in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 15, pp. 6248-6258, 2022, doi: 10.1109/JSTARS.2022.3195120

Tags: EARTH SCIENCES, Ground-based measurements, Landsat 8, Reflectance, Sentinel 2a/b, Uncertainty estimation, Validation
Organization: Geoscience Australia Data
Learnings from the Gawler Craton Airborne Survey Quality Control

The Geological Survey of South Australia (GSSA) designed the Gawler Craton Airborne Survey (GCAS) to provide high resolution magnetic, gamma ray and elevation data covering the northern portion of the Gawler Craton.  In total, 1.66 million line km were planned over of 295,000 km2, covering approximately 30% of the state of South Australia.
The survey design of 200m spaced lines at a ground clearance of 60m can be compared with the design of existing regional surveys which generally employed 400m line spacing and a ground clearance of 80m.  The new survey design results in ~2x the data coverage and ~25% closer to the ground when compared to previous standards for regional surveys in South Australia.  
Due to the enormous scale of the survey, the data were acquired using FOUR contractors who employed TEN systems to fly the SIXTEEN blocks.  
To standardise the data from the multitude of systems, Geoscience Australia (GA) employed a comprehensive set of technical specifications.  As part of these specifications the contractors were required to fly each of the TEN systems over a series of test lines termed the “Whyalla Test Lines” (Whyalla).  
The final GCAS data provide truly impressive high resolution regional scale products. These will undoubtedly allow more detailed geological interpretation of the prospective Gawler Craton. 
A laser altimeter was added to the list of required survey equipment. Deficiencies in the technical specifications relating to laser altimeters were identified. Standards and procedures specific to laser characteristics will need to be considered on future surveys.
Analyses show that weaknesses in current standards and procedures are still evident. The weaknesses identified allow room for improvements to be made for future surveys.
Gamma ray processing results raised the most serious concerns, with repeatability not achieved. Changes to standard procedures may need to be considered.
Presented at the 2nd Australasian Exploration Geoscience Conference (AEGC2019)

Tags: EARTH SCIENCES, GEOPHYSICS, Geophysics not elsewhere classified, Published_External
Organization: Geoscience Australia Data
Sedimentary thickness across Australia from passive seismic methods

Around the world the Earth's crust is blanketed to various extents by sedimentary cover. For continental regions, knowledge of the distribution and thickness of sediments is crucial for a wide range of applications including seismic hazard, resource potential, and our ability to constrain the deeper crustal geology. Excellent constraints on the sedimentary thickness can be obtained from borehole drilling or active seismic surveys. However, these approaches are expensive and impractical in remote continental interiors such as central Australia. 

Recently, a method for estimating the sedimentary thickness using passive seismic data, the collection of which is relatively simple and low-cost, was developed and applied to seismic stations in South Australia. This method uses receiver functions, specifically the time delay of the \P{}-to-\S{} converted phase generated at the sediment-basement interface, relative to the direct-P arrival, to generate a first order estimate of the thickness of sedimentary cover. In this work we expand the analysis to the vast array of over 1500 seismic stations across Australia, covering an entire continent and numerous sedimentary basins that span the entire range from Precambrian to present-day. We compare with an established yet separate method to estimate the sedimentary thickness, which utilises the autocorrelation of the radial receiver functions to ascertain the two-way travel-time of shear waves reverberating in a sedimentary layer.

Across the Australian continent the new results clearly match the broad pattern of expected sedimentation based on the various geological provinces. Furthermore we are able to delineate the boundaries of many sedimentary features, such as the Eucla and Murray Basins, which are Cenozoic, and the boundary between the Karumba Basin and the mineral rich Mount Isa Province. The signal is found to diminish for older Proterozoic basins, likely due to compaction and metamorphism of the sediments over time. Finally, a comparison with measurements of sedimentary thickness from local boreholes allows for a straightforward predictive relationship between the delay time and the cover thickness to be defined. This offers future widespread potential, providing a simple and cheap way to characterise the sedimentary thickness in under-explored areas from passive seismic data. 

This study and some of the data used are funded and supported by the Australian Government's Exploring for the Future program led by Geoscience Australia.
Citation: Augustin Marignier, Caroline M Eakin, Babak Hejrani, Shubham Agrawal, Rakib Hassan, Sediment thickness across Australia from passive seismic methods, Geophysical Journal International, Volume 237, Issue 2, May 2024, Pages 849–861, https://doi.org/10.1093/gji/ggae070

Tags: Australia’s Resources Framework - ARF, Cover thickness, Exploration For the Future - EFTF, Published_External, Seismology and Seismic Exploration, passive seismic, reciever functions, sedimentary cover
Organization: Geoscience Australia Data
Exploring for the Future geomechanics: Breaking down barriers to exploration

Exploring for the Future (EFTF) is an Australian Government initiative focused on gathering new data and information about potential mineral, energy and groundwater resources across northern Australia. This area is generally under-explored and offers enormous potential for industry development, as it is advantageously located close to major global markets, infrastructure and hosts many prospective regions. In June 2020, the Hon Keith Pitt MP, Minister for Resources, Water and Northern Australia, announced a four year extension to this program with an expansion in scope to cover the whole of Australia. 
The energy component of EFTF aims to improve our understanding of the petroleum potential of frontier Australian basins. Building an understanding of geomechanical rock properties is key to understanding both conventional and unconventional petroleum systems as well as carbon storage and sedimentary geothermal systems. Under EFTF, Geoscience Australia has undertaken geomechanical work including stress modelling, shale brittleness studies, and the acquisition of new rock property data through extensive testing on samples from the Paleo- to Mesoproterozoic South Nicholson region of Queensland and the Northern Territory and the Paleozoic Kidson Sub-basin of Western Australia. These analyses are summarised herein.
Providing baseline geomechanical data in frontier basins is essential as legacy data coverage can often be inadequate for making investment decisions, particularly where unconventional plays are a primary exploration target. As EFTF increases in scope, Geoscience Australia anticipates expanding these studies to encompass further underexplored regions throughout Australia, lowering the barrier to entry and encouraging greenfield exploration.
Citation: Bailey Adam H. E., Jarrett Amber J. M., Wang Liuqi, Dewhurst David N., Esteban Lionel, Kager Shane, Monmusson Ludwig, Carr Lidena K., Henson Paul A. (2021) Exploring for the Future geomechanics: breaking down barriers to exploration. The APPEA Journal 61, 579-587.
https://doi.org/10.1071/AJ20039

Tags: Barnicarndy 1, Canning Basin, EARTH SCIENCES, Exploring for the Future - EFTF, Isa Superbasin, Kidson Sub-basin, Poisson's rtion, Published_External, South Nicholson region, Young's modulus, brittleness, geomechanics, in situ stress, mineralogy, permeability, porosity, present-day stress, rock stength, seal capacity, stiffness, stress regimes, velocity
Organization: Geoscience Australia Data
Certainty and Stability, Australia Maritime Boundaries in a Changing World

Geoscience Australia has the mandated authority for determining the Australia’s maritime jurisdiction and the framework for managing marine resources including supporting marine planning: 
deliver certainty, stability, predictability and visibility to Australia’s international and domestic boundaries

deliver systems that support planning in the maritime jurisdiction

support our neighbours in the region to address global priority issues in collaboration with the Department of Foreign Affairs and Trade (DFAT)
This presentation (May 2025) will communicate the benefits and progress associated with the digital transformation of maritime boundaries both within Australia, under Australian-led international programs and global influence.

Tags: Cartography and digital mapping, Jurisdiction, Maritime boundaries, Ocean governance, Published_External
Organization: Geoscience Australia Data