AndreaBozzo/ceres-open-data-index huggingface dataset:
A national-scale mineral potential assessment for carbonatite-related rare earth element mineral systems in Australia

The production of rare earth elements is critical for the transition to a low carbon economy. Carbonatites (&gt;50% carbonate minerals) are one of the most significant sources of rare earth elements (REEs), both domestically within Australia, as well as globally. Given the strategic importance of critical minerals, including REEs, for the Australian national economy, a mineral potential assessment has been undertaken to evaluate the prospectivity for carbonatite-related REE (CREE) mineralisation in Australia. CREE deposits form as the result of lithospheric- to deposit-scale processes that are spatially and temporally coincident.

Building on previous research into the formation of carbonatites and their related REE mineralisation, a mineral system model has been developed that incorporates four components: (1) source of metals, fluids, and ligands, (2) energy sources and fluid flow drivers, (3) fluid flow pathways and lithospheric architecture, and (4) ore deposition. This study demonstrates how national-scale datasets and a mineral systems-based approach can be used to map the mineral potential for CREE mineral systems in Australia.

Using statistical analysis to guide the feature engineering and map weightings, a weighted index overlay method has been used to generate national-scale mineral potential maps that reduce the exploration search space for CREE mineral systems by up to ∼90%. In addition to highlighting regions with known carbonatites and CREE mineralisation, the mineral potential assessment also indicates high potential in parts of Australia that have no previously identified carbonatites or CREE deposits.

Citation: Ford, A., Huston, D., Cloutier, J., Doublier, M., Schofield, A., Cheng, Y., and Beyer, E., 2023. A national-scale mineral potential assessment for carbonatite-related rare earth element mineral systems in Australia, Ore Geology Reviews, V. 161, 105658. https://doi.org/10.1016/j.oregeorev.2023.105658

Tags: Australia’s Resources Framework, Data mining and knowledge discovery, EFTF – Exploring for the Future, Earth Sciences, Mineral potential, Published_External, carbonatites, critical minerals, mineral systems, rare earth elements
Organization: Geoscience Australia Data
A continuous, proxy-based rock mechanical approach for developing mechanical frameworks at CO2 storage sites

We present results from a multidisciplinary rock mechanics study designed to develop a high resolution mechanical framework of the lower Paaratte Formation, a reservoir used for CO2  storage at the CO2CRC Otway Project, Otway Basin Victoria. A continuous high-resolution record of unconfined compressive strength (UCS) was determined through the scratch technique along approximately 80 m of CRC-2 core. Multiple correlations between UCS and several different wireline log suites resulted in the development of a strength proxy that can accurately predict strength and lithologic transitions. The strength proxy was then applied to a section of the CRC-1 well which traverses the Naylor South splay fault. The proxy predicts a UCS of approximately 20 MPa for the splay fault, which is a central learning as it constrains a key parameter that is used in fault stability modelling. A number of triaxial rock mechanical tests were also conducted to complement the scratch testing and also characterise the poroelastic properties of the various units. UCS and stiffness of the rocks appear to be positively correlated, albeit with significant data scatter and data gaps at moderate strength values. The workflow developed in this study provides a more accurate and higher resolution mechanical framework to be developed at potential CCS sites and provide a predictive methodology for mechanical properties when actual mechanical tests may be absent.
Citation: Eric Tenthorey, Thomas Richard, David N. Dewhurst, A continuous, proxy-based rock mechanical approach for developing mechanical frameworks at CO2 storage sites, International Journal of Greenhouse Gas Control, Volume 85, 2019, Pages 36-45, ISSN 1750-5836, https://doi.org/10.1016/j.ijggc.2019.03.028.

Tags: CO2 storage, Carbon capture storage - CCS, EARTH SCIENCES, Otway, Published_External, geomechanics, proxy, rock mechanics, scratch, strength, triaxial, unconfined compressive strength - UCS
Organization: Geoscience Australia Data
A statistical-parametric model of tropical cyclones for hazard assessment

We present the formulation of an open-source, statistical–parametric model of tropical cyclones (TCs) for use in hazard and risk assessment applications. The model derives statistical relations for TC behaviour (genesis rate and location, intensity, speed and direction of translation) from best-track datasets, then uses these relations to create a synthetic catalogue based on stochastic sampling, representing many thousands of years of activity. A parametric wind field, based on radial profiles and boundary layer models, is applied to each event in the catalogue that is then used to fit extreme-value distributions for evaluation of return period wind speeds. We demonstrate the capability of the model to replicate observed behaviour of TCs, including coastal landfall rates which are of significant importance for risk assessments.
Citation: Arthur, W. C.: A statistical–parametric model of tropical cyclones for hazard assessment, Nat. Hazards Earth Syst. Sci., 21, 893–916, https://doi.org/10.5194/nhess-21-893-2021, 2021.

Tags: EARTH SCIENCES, Published_External, hazard and risk assessment, statistical–parametric model, tropical cyclones - TCs, wind field
Organization: Geoscience Australia Data
Extracting the intertidal extent and topography of the Australian coastline from a 28 year time series of Landsat observations

The physical environment of the intertidal zone presents a number of challenges which make traditional surveying methods difficult to implement; whilst the acquisition cost of airborne elevation data can be prohibitive beyond localised applications. Remote sensing data from earth observation satellites has been well established as a method for mapping the extent and elevation profile of the intertidal zone; however the majority of these applications are local in nature, and based on analysis of a limited number of individual image observations.
In this paper we outline an automated methodology to model the intertidal extent and topography of the Australian coastline, that leverages a full time series of Landsat observations from 1987-2015 managed in the Australian Geoscience Data Cube (AGDC). Our approach reframes the analysis from time of acquisition into the tidal domain through the use of a continental scale tidal model, combined with a median pixel compositing of Normalised Difference Water Index (NDWI) stacks, to robustly estimate the tidal extent and elevation profile across the observed tidal range. We demonstrate the ability of a median-based compositing approach to deal effectively with data quality, modelling outliers and other issues that commonly affect single scene methodologies. Our new framework enables us to create a continental-scale intertidal model, detailing intertidal zone topography at a 25m spatial scale.
We then demonstrate the potential of the modelling framework to derive digital elevation data based on tidal model attribution, validating our models against in-situ GPS observations, before discussing issues that must be addressed to move this capability to a continental scale. The ability of the model to examine coastal stability is introduced, in the context of the  conceptual reframing of the data into the tidal domain, with a view to furthering this application in future versions of the model.
Citation: Stephen Sagar, Dale Roberts, Biswajit Bala, Leo Lymburner, Extracting the intertidal extent and topography of the Australian coastline from a 28year time series of Landsat observations, Remote Sensing of Environment, Volume 195, 2017, Pages 153-169, ISSN 0034-4257, https://doi.org/10.1016/j.rse.2017.04.009.

Tags: Coastal, EARTH SCIENCES, Elevation, Image compositing, Intertidal, Landsat, Published_External, Tidal modelling, Time-series, Topography
Organization: Geoscience Australia Data
Trans-dimensional Bayesian inversion of Airborne Electromagnetic data for 2D conductivity profiles

This paper presents the application of a novel trans-dimensional sampling approach to a time domain airborne electromagnetic (AEM) inverse problem to solve for plausible conductivities of the subsurface. Geophysical inverse problems, such as time domain AEM, are well known to have a large degree of non-uniqueness. Common least-squares optimization approaches fail to take this into account and provide a single solution with linearized estimates of uncertainty which can result in overly optimistic appraisal of the conductivity of the subsurface. In this new non-linear approach, the spatial complexity of a 2D profile is controlled directly by the data. By examining an ensemble of proposed conductivity profiles it accommodates non-uniqueness and provides more robust estimates of uncertainties.
Citation: Hawkins, R., Brodie, R. C., &amp; Sambridge, M. (2018). Trans-dimensional Bayesian inversion of airborne electromagnetic data for 2D conductivity profiles. Exploration Geophysics, 49(2), 134–147. https://doi.org/10.1071/EG16139

Tags: Bayisian, EARTH SCIENCES, Published_External, airborne electromagnetic - AEM, inversion, non-uniqueness, trans-dimensional, uncertainty
Organization: Geoscience Australia Data
Baseline biogeochemical data from Australia’s continental margin links seabed sediments to water column characteristics

Surficial marine sediments are an important source of nutrients for productivity and biodiversity yet the biogeochemistry of these sediments is poorly known in Australia. Seabed samples were collected at &gt;350 locations in Australia’s western, northern and eastern continental margins during federal government surveys (2007-2014). Parameters analysed included measures of organic matter (OM) source (δ13C, δ15N and C:N-ratios), concentration (total organic carbon (%TOC) and surface area normalised TOC (OC:SA)) and bioavailability (chlorin indices, total reactive chlorins, total oxygen uptake, total sediment metabolism (TSM), sediment oxygen demand (SOD) and SOD and TSM normalised to TOC). The aim of this study is to summarise these biogeochemical ‘baseline’ data, and make contextualised inferences about processes that govern the observed concentrations.  The OM was mainly from marine sources and OC:SA broadly reflected water column productivity (MODIS). Approximately 40% of sediments were organic-poor by global standards reflecting seawater oligotrophy; ~12% were organic-rich due to benthic production, high water column productivity and pockmark formation. OM freshness varied due to pigment degradation in water columns and dilution with refractory OM in reworked sediments. δ15N values confirmed the importance of N2 fixation to Timor Sea productivity, and point to recycling of fixed nitrogen within food chains in Western Australia.
Citation: Radke Lynda, Nicholas Tony, Thompson Peter A., Li Jin, Raes Eric, Carey Matthew, Atkinson Ian, Huang Zhi, Trafford Janice, Nichol Scott (2017) Baseline biogeochemical data from Australia’s continental margin links seabed sediments to water column characteristics. Marine and Freshwater Research 68, 1593-1617. 
https://doi.org/10.1071/MF16219

Tags: EARTH SCIENCES, Published_External, Trichodesmium, diazotroph, marine, geochemistry, seabed, sediments, organic carbon, particulate, totol nitrogen
Organization: Geoscience Australia Data
Towards a wide-scale land subsidence product in Eastern states of Australia

The implementation of a wide-land deformation monitoring program in eastern states of Australia, characterized by an extensive landmass and extensive coastlines, necessitates the generation of deformation maps with a significantly larger spatial extent. A pragmatic approach for achieving such coverage involves the integration of multiple interferometric synthetic aperture radar (InSAR) time series results encompassing various tracks and frames. The Sentinel-1 satellite constellation is facilitating the generation of expansive ground surface deformation, while the initial challenge in obtaining such a product arises from the varying spatial coverage of the Sentinel-1 data. To overcome this obstacle, we proposed a novel Sentinel-1 image definition to facilitate consistent interferometric processing. Before the formation of any large displacement map, the inconsistency between different synthetic aperture radar (SAR) image scenes must, nevertheless, be addressed. Several factors contribute to these inconsistencies in observations, such as differences in the angle of observation at the overlapping regions of adjacent image tracks and imprecise estimations within the dataset itself (e.g., burst or swath discontinuities). This study delves into solutions for these challenges, specifically: 1) introducing a computer-vision-based algorithm for  InSAR dataset quality assessment and 2) proposing a global least square mosaicking procedure for the amalgamation of tiles from multitracks and frames. Statistical analyses show that better accuracy can be achieved. The mosaicking InSAR product demonstrates the capacity to quantify ground surface changes, which also exhibits a correlation with other geological layers, and the subsidence range of [−7, 10] mm/year shows a strong association with clay content levels ranging from 10% to 30% along the Darling River.
Citation: Z. Du et al., "Toward a Wide-Scale Land Subsidence Product in Eastern States of Australia," in IEEE Transactions on Geoscience and Remote Sensing, vol. 61, pp. 1-12, 2023, Art no. 5213312, doi: 10.1109/TGRS.2023.3299928.

Tags: Australia, Australia subsidence mapping, InSAR, Photogrammetry and Remote Sensing, Published_External, big data, continental-scale, land subsidence
Organization: Geoscience Australia Data
Applied geophysics for cover thickness mapping in the southern Thomson Orogen

Potentially mineralised Paleozoic basement rocks in the southern Thomson Orogen region of south-ern Queensland and northern New South Wales are covered by varying thicknesses of Mesozoic to Cenozoic sediments. To assess cover thickness and methods for estimating depth to basement, we collected new airborne electromagnetic (AEM), seismic refraction, seismic reflection and audio-frequency magnetotelluric data and combined these with new depth to magnetic basement models from airborne magnetic line data and ground gravity data along selected transects. The results of these investigations over two borehole sites, GSQ Eulo 1 and GSQ Eulo 2, show that cover thickness can be reliably assessed to within the confidence limits of the various techniques, but that caveats exist regarding the application of each of the disciplines. These techniques are part of a rapid-deployment explorers’ toolbox of geophysical techniques that have been tested at two sites in Australia, the Stavely region of western Victoria, and now the southern Thomson Orogen in northern New South Wales and southern Queensland. The results shown here demonstrate that AEM and ground geophysics, and to a lesser extent depth to magnetic source modelling, can produce reliable results when applied to the common exploration problem of determining cover thickness. The results demonstrate that portable seismic systems, designed for geotechnical site investigations, are capable of imaging basement below 300 m of unlithified Eromanga Basin cover as refraction and reflection data. The results of all methods provide much information about the nature of the basement–cover interface and basement at borehole sites in the southern Thomson Orogen, in that the basement is usually weathered, the interface has paleotopography, and it can be recognised by its density, natural gamma, magnetic susceptibility and electrical conductivity contrasts.
Citation: Roach, I. C., Folkes, C. B., Goodwin, J., Holzschuh, J., Jiang, W., McPherson, A. A., &amp; Meixner, A. J. (2018). Applied geophysics for cover thickness mapping in the southern Thomson Orogen. Australian Journal of Earth Sciences, 65(7–8), 917–941. https://doi.org/10.1080/08120099.2018.1452295

Tags: EARTH SCIENCES, Electrical and Electromagnetic Methods in Geophysics, Magnetism and Palaeomagnetism, Seismology and Seismic Exploration, Thomson Orogen, UNCOVER, applied geophysics, cover thickness mapping, depth to basement, mineral exploration, risk redutcion
Organization: Geoscience Australia Data
Delayed subsidence after rifting and a record of breakup for northwestern Zealandia

Continental rifting and breakup of eastern Gondwana during the Cretaceous separated northern Zealandia from eastern Australia, but the processes leading to this highly-extended and largely submerged block of continental crust are unknown. We acquired and processed multi-channel seismic reflection data across northern Zealandia and examine the stratigraphy of the Middleton Basin. We identified a two-phase formation process for the basin, as evidenced by an unconformity separating two post-rift units. After initial basin formation and slow deposition of the lower post-rift unit, deposition rates within the Middleton Basin rapidly increased in response to the latest-stage of subsidence and to create the modern basin. We propose a tectonic model wherein the Middleton Basin initiated through oceanic spreading and the subsequent post-rift subsidence of the newly created oceanic lithosphere was delayed due to thermal buoyancy associated with nearby oceanic spreading in the Tasman Basin. Our results provide new constraints on rifting and breakup processes of wide, magma-poor and asymmetric margins and indicate that multiple regions of weak lithosphere may have influenced the breakup.
Citation: Boston, B., Nakamura, Y., Gallais, F., Hackney, R., Fujie, G., Kodaira, S., et al.(2019). Delayed subsidence after rifting and a record of breakup for north western Zealandia. Journal of Geophysical Research: Solid Earth,124, 3057–3072.
https://doi.org/10.1029/2018JB016799

Tags: EARTH SCIENCES, Lord Howe Rise, Middleton Basin, Southwest Pacific, Zealandia, seismic reflection, tectonics
Organization: Geoscience Australia Data
A Review and Meta-Analysis of Potential Impacts of Ocean Acidification on Marine Calcifiers From the Southern Ocean

Understanding the vulnerability of marine calcifiers to ocean acidification is a critical issue, especially in the Southern Ocean (SO), which is likely to be the one of the first, and most severely affected regions. Since the industrial revolution, ~30% of anthropogenic CO2 has been absorbed by the global oceans. Average surface seawater pH levels have already decreased by 0.1 and are projected to decline by ~0.3 by the year 2100. This process, known as ocean acidification (OA), is shallowing the saturation horizon, which is the depth below which calcium carbonate (CaCO3) dissolves, likely increasing the vulnerability of many resident marine calcifiers to dissolution. The negative impact of OA may be seen first in species depositing more soluble CaCO3 mineral phases such as aragonite and high-Mg calcite (HMC). Ocean warming could further exacerbate the effects of OA in these particular species. Here we combine a review and a quantitative meta-analysis to provide an overview of the current state of knowledge about skeletal mineralogy of major taxonomic groups of SO marine calcifiers and to make projections about how OA might affect a broad range of SO taxa. We consider a species' geographic range, skeletal mineralogy, biological traits, and potential strategies to overcome OA. The meta-analysis of studies investigating the effects of the OA on a range of biological responses such as shell state, development and growth rate illustrates that the response variation is largely dependent on mineralogical composition. Species-specific responses due to mineralogical composition indicate that taxa with calcitic, aragonitic, and HMC skeletons, could be at greater risk to expected future carbonate chemistry alterations, and low-Mg calcite (LMC) species could be mostly resilient to these changes. Environmental and biological control on the calcification process and/or Mg content in calcite, biological traits, and physiological processes are also expected to influence species-specific responses.
Citation: Figuerola B, Hancock AM, Bax N, Cummings VJ, Downey R, Griffiths HJ, Smith J and Stark JS (2021) A Review and Meta-Analysis of Potential Impacts of Ocean Acidification on Marine Calcifiers From the Southern Ocean. Front. Mar. Sci.8:584445. doi: 10.3389/fmars.2021.584445

Tags: Antarctica, ECOLOGY, Ecological Impacts of Climate Change, Published_External, aragonite, carbonate mineralogy, climate change, magnesium, marine calcifiers, saturation horizon, vulnerability
Organization: Geoscience Australia Data
Successive marine heatwaves cause significant coral bleaching impacts during a fast phase transition from El Niño to La Niña

The frequency and intensity of marine heatwaves resulting in thermal bleaching events have increased over recent decades leading to catastrophic losses of reef-building corals in many regions. Successive annual bleaching events are also becoming more frequent, limiting the capacity of susceptible coral species to recover. Following an unusual fast phase transition of the record-breaking 2009–2010 warm pool El Niño event in the Central Pacific to a strong La Niña event the following year, high-latitude coral reef assemblages around Lord Howe Island were exposed to unprecedented successive thermal anomalies causing severe bleaching. Coral health surveys completed between March 2010 and September 2012 quantified the response and resilience of approximately 42,000 coral colonies from different taxa to the successive bleaching events. Changes in benthic community composition before, during and after the thermal stress events were also assessed. In March 2010, severe coral bleaching ranged between 99% at some shallow lagoon sites to 17% at deeper reef slope sites. Significant coral tissue mortality was evident during March and May 2010, with increased pigmentation and colour returning to surviving colonies by September 2010, indicating recovery of symbiotic function in living coral colonies. Pocillopora, Stylophora, Porites and Montipora species were the most affected taxa, with minimal mortality observed in merulinid and Acropora species. During the second thermal anomaly in 2011, significant bleaching occurred in susceptible coral taxa, demonstrating limited resilience and acclimation capacity of these high-latitude corals to future-ocean warming. Repeated bleaching stress resulted in a shift at some sites from a coral-dominated reef assemblage to one comprising a higher cover of macroalgae and other invertebrate taxa. These findings demonstrate that future-ocean warming and extreme heatwave events are likely to lead to significant shifts in reef assemblages and potential local extinction of some dominant but vulnerable reef-building corals at this world heritage listed site.
Citation: Steven J. Dalton, Andrew G. Carroll, Eugenia Sampayo, George Roff, Peter L. Harrison, Kristina Entwistle, Zhi Huang, Anya Salih, Sandra L. Diamond, Successive marine heatwaves cause disproportionate coral bleaching during a fast phase transition from El Niño to La Niña, Science of The Total Environment, Volume 715, 2020, 136951, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2020.136951.

Tags: Coral bleaching, EARTH SCIENCES, El Nino, La Nina, Published_External, marine heatwaves
Organization: Geoscience Australia Data