Joël Brugger

• Professor at Monash University (Australia)

The formation of epithermal gold deposits is closely linked to the evolution of hydrothermal fluids, but the factors controlling the partitioning of gold and arsenic into sulfide minerals within the evolutionary framework remains poorly understood. Here, we present the spatial zoning of mineral assemblages, trace elements, and sulfur isotopic fract...

Ethnographic accounts of Melanesian exchange systems, such as the Kula and Hiri, have significantly influenced the development of anthropology. These accounts primarily focus on male agency framed by heroic seafaring ventures, while the agency of women and their cultural practices—key to the interconnectedness of Melanesian societies—has often been...

The accurate characterisation of regolith materials is crucial for mineral exploration, yet distinguishing visually indistinct clay-rich samples can be challenging and labour-intensive. This study conducts unsupervised k-means clustering and principal component analysis (PCA) on a geochemical dataset of over 3000 regolith samples from the Splinter...

Windows are essential for advancing energy efficiency, yet fabricating window materials that simultaneously achieve high visible light transmission, exceptional and ultrabroadband near-infrared (NIR) shielding, neutral color appearance, excellent stability, and cost-effective, sustainable production remains a significant challenge. This study intro...

Understanding elements uptake and release from minerals in source rocks is crucial for comprehending critical metals accumulation, yet the mechanisms and kinetics of element mobilization at the atomic scale remain mostly unknown. Here, we analyzed the distribution of cobalt (Co) in natural pyrite from a Cu-Co ore deposit and found that metals distr...

Uranium is found in various types of rocks. HERFD-XRF imaging at the U M4 edge is a novel non-destructive technique that visualizes the distribution of U (IV), (V), and (VI)...

Smart windows are essential for advancing energy efficiency, yet fabricating window materials that simultaneously achieve high visible light transmission, exceptional and ultrabroadband near-infrared (NIR) shielding, neutral color appearance, excellent stability, and cost-effective, sustainable production remains a significant challenge. This study...

Understanding the behaviour of tantalum (Ta) in hydrothermal systems is pivotal for understanding its geochemical enrichment processes and economic extraction via hydrometallurgy. Yet, its behaviour in hydrothermal systems remains poorly characterised. This study investigates the coordination chemistry, speciation, and solubility of pentavalent Ta(...

High-grade copper ores are becoming depleted, while globally increasing copper demand, in part led by the transition away from fossil fuels and towards renewable energy sources, is set to outpace Cu production in the near-term. Hydrometallurgical processing is becoming increasingly important to treat lower-grade and more complex copper ores where f...

Gold nuggets occur predominantly in quartz veins, and the current paradigm posits that gold precipitates from dilute (<1 mg kg⁻¹ gold), hot, water ± carbon dioxide-rich fluids owing to changes in temperature, pressure and/or fluid chemistry. However, the widespread occurrence of large gold nuggets is at odds with the dilute nature of these fluids a...

___________________________________________________________________________ Session: The Role of Ultramafic Rocks in Carbon Capture and Storage-Poster Mineral carbonation represents one of the most favourable CO2 storage options, as it ensures the permanent trapping of CO2 in stable carbonate minerals. Serpentinites are an ideal starting material b...

Apatite, rhabdophane and monazite are actinide- and rare-earth element (REE)-bearing phosphate minerals with diverse geoscientific applications. However, their mineral-fluid reaction mechanisms below 200 °C are understudied. Insufficient understanding as to how these minerals behave during hydrothermal alteration impedes useful interpretations of R...

The High Field Strength Elements (HFSE) Ti, Nb and rare earth elements (REE) are commonly regarded as immobile during hydrothermal activity and metamorphism, making them important tracers of geological processes. Here, we report a Ti-REE-Nb-As mineralisation recently discovered in quartz, feldspar, muscovite ± biotite, fluorapatite, hematite, epido...

Hyperenrichment of Au in orogenic ores occurs overwhelmingly within quartz veins, but the formation pathway of quartz veins in orogenic systems remains enigmatic. We conducted hydrothermal experiments simulating coprecipitation of Au and amorphous silica and subsequent recrystallization to test whether this is a viable mechanism to generate Au nugg...

In this study, two types of recycling scenarios are assessed for spent battery materials using froth flotation. The first is for a single cathode chemistry and would be considered as the most likely scenario for a large battery manufacturer, who takes back their own batteries for reprocessing. The second scenario is for mixed cathode chemistry, and...

The stratiform and vein-hosted Kapunda Cu deposit in South Australia contains a saprolitized hydrothermal vein with 12.37 wt.% total rare earth oxide (TREO). The vein was analyzed by X-ray diffraction, scanning electron microscopy, synchrotron-based X-ray fluorescence microscopy and electron backscatter diffraction to understand the controls that g...

A plutonium-rich carbide, (U,Pu)(Al,Fe)3C3, was discovered in a hot particle from the Maralinga nuclear testing site in South Australia. The particle was produced between 1960 and 1963 and has been exposed to ambient conditions since then. The new phase belongs to a group of ternary carbides known as 'derivative-MAX phases'. It formed at high tempe...

In a series of four extended industrial column leach experiments spanning 542 days, aimed at examining Cu-recovery from low-grade sulfide ores, all instances yielded suboptimal Cu recovery rates (< 27%). Through a nuanced analysis integrating time-resolved chemical data on leachate with detailed mineralogical investigations, we highlight that the d...

Copper concentrates represent 80% of the world's copper production. The main processing routes for copper extraction are pyrometallurgical via smelting or hydrometallurgical using moderate to high temperatures and/or high-pressure conditions, which affects the processing costs. An alternative presented in this work is the mechanochemical processing...

Microorganisms inhabiting uranium (U)-rich environments have specific physiological and biochemical coping mechanisms to deal with U toxicity, and thereby play a crucial role in the U biogeochemical cycling as well as associated heavy metals. We investigated the diversity and functional capabilities of indigenous bacterial communities inhabiting hi...

Wortupaite (IMA2022–107) is a new hydrated magnesium nickel tellurite mineral with a zemannite-like structure, described from the Wortupa gold mine, South Australia, Australia. Wortupaite forms needles up to 25 μm in length, generally clustered and sometimes in blocky masses of shorter (10‒15 μm) crystals. Wortupaite is found growing on melonite, f...

Specialised microbial communities colonise the surface of gold particles in soils/sediments, and catalyse gold dissolution and re-precipitation, thereby contributing to the environmental mobility and toxicity of this 'inert' precious metal. We assessed the proteomic and physiological response of Serratia proteamaculans, the first metabolically acti...

Zeolite LTA is one of the largest industrial zeolites in both volume and market value. Natural resources or manufacturing wastes such as clay minerals, fly ash, and lithium slag are now used as raw materials for the economically and environmentally friendly synthesis of zeolites. However, soluble impurities such as inorganic anions (CO 3 2− , SO 4...

The structure of the uranyl aqua ion (UO22+) and a number of its inorganic complexes (specifically, UO2Cl+, UO2Cl20, UO2SO40, [Formula: see text] , [Formula: see text] and UO2OH42-) have been characterised using X-Ray absorption spectroscopy/extended X-Ray absorption fine structure (XAS/EXAFS) at temperatures ranging from 25 to 326 ºC. Results of a...

A long-standing debate on the genesis of magmatic-hydrothermal Cu-Au deposits is whether the elevated oxygen fugacity (fO2) and metal endowment of their parental magmas are inherited from the mantle source or acquired during fractionation within the crust. This debate is built mainly on the composition of magmas emplaced into the upper crust that u...

The critical metal germanium (Ge) is recovered as a by-product of mining other commodities, such as zinc and thermal coal. We investigated the Ge incorporation mechanism in sphalerite synthesized under hydrothermal conditions like those of sediment-hosted Zn-Pb deposits. Sphalerite ± galena ± barite formed via reactions of Ge ± Fe ± Cu-bearing brin...

The Wulong gold deposit (> 80 t Au) is located at the northeastern margin of the North China Craton (NCC). Gold in the most economically important quartz veins (Stages 2 and 3) is associated with a varied assemblage of Bi and Te minerals. Stage 2 is characterized by, in a temporal order, native gold-native bismuth-maldonite-hedleyite, bismuthinite-...

Reactions among minerals occur via solid-state diffusion or fluid-induced, interface-coupled dissolution-reprecipitation (ICDR). Both mechanisms can coexist under conditions where the rates of both processes are similar, depending mainly on the nature of the mineral, temperature, and fluid composition. To clarify the synergies between these reactio...

Near-infrared (NIR)-shielding glasses for energy-saving window applications were prepared by forming sodium tungsten bronze-like (Na5W14O44) functional units in the 29SiO2–43B2O3–28NaF glass matrix. The glasses were synthesized by a facile melt-quenching process where 4–8 mol.% H2WO4 was added as the W source. The optimal glass was produced using 6...

Tellurium (Te) is a Critical Element that is toxic to microorganisms and humans alike, most notably in its soluble oxyanionic forms. To date, the biogeochemical behaviour of Te in Earth’s surface environment is largely unknown. Here, we report the discovery of elemental Te nanoparticles (Te NPs) in regolith samples using Single-Particle Inductively...

The solubility and speciation of zinc (Zn) in chloride-bearing aqueous fluids at high temperature and pressure are important for understanding Zn transport in natural hydrothermal systems and associated mineralizing processes. Here, we measured sphalerite solubility in NaCl-HCl-H2O fluids using a fixed-volume titanium alloy hydrothermal reactor equ...

Rare earth elements (REE), essential metals for the transition to a zero-emission economy, are mostly extracted from REE-fluorcarbonate minerals in deposits associated with carbonatitic and/or peralkaline magmatism. While the role of high-temperature fluids (100 < T < 500 °C) in the development of economic concentrations of REE is well-established,...

Chlorine is the most common ligand in geofluids, and one of the most important complexing agents for rare earth elements. The geometry and thermodynamic properties of La(III)-Cl complexes determined by previous experimental studies show inconsistency especially at temperature over 350 C. Here, ab initio molecular dynamics (MD) simulations were empl...

Rare Earth elements (REE) are gaining importance due to their increasing industrial applications and usefulness as petrogenetic indicators. REE-sulfate complexes are some of the most stable REE aqueous species in hydrothermal fluids, and may be responsible for REE transport and deposition in a wide variety of geological environments, ranging from s...

Hydrothermal fluids enriched in halogens (e.g., F and Cl) are essential for ore formation as well as associated alteration processes. Chloride-bearing solutions facilitate mineral re-equilibration and metal mass transfer by forming soluble complexes with Cl⁻. Fluorine is enriched in a variety of hydrothermal ore deposits and their alteration halos,...

Tellurium (Te) is a Critical Mineral and its biogeochemical behaviour has mostly been interpreted from laboratory-based studies rather than direct field observations, due to the scarcity of Te in the environment. The historic mining district of Moctezuma, Sonora, Mexico, hosts the only Au mine worldwide where native tellurium is the main ore minera...

Phosphorus is an essential element for life, and the phosphorous cycle is widely believed to be a key factor limiting the extent of Earth's biosphere and its impact on remotely detectable features of Earth's atmospheric chemistry. Continental weathering is conventionally considered to be the only source of bioavailable phosphorus to the marine bios...

Accepted in Geophysical Research Letters (9/20/21)

Quantitative understanding of uranium transport by high temperature fluids is crucial for confident assessment of its migration in a number of natural and artificially induced contexts, such as hydrothermal uranium ore deposits and nuclear waste stored in geological repositories. An additional recent and atypical context would be the seawater inund...

The dynamic evolutions of fluid-mineral systems driving large-scale geochemical transformations in the Earth’s crust remain poorly understood. We observed experimentally that successive sodic and potassic alterations of feldspar can occur via a single self-evolved, originally Na-only, hydrothermal fluid. At 600 °C, 2 kbar, sanidine ((K,Na)AlSi3O8)...

The fluid-driven transformation of chalcopyrite (CuFeS2) into Cu-rich sulfides (e.g., digenite, Cu1.8S; covellite, CuS; and chalcocite, Cu2S) is a complex mineral replacement reaction where the reaction pathway is controlled by the interplay between evolving mineral make-up, texture/porosity, and solution chemistry. This transformation was investig...

This paper presents the results of an investigation of the incorporation of Au within pyritic ore from the Qiucun epithermal Au deposit, China. The new data provide insights into the mode of occurrence of Au during fluid-rock interactions within epithermal systems. The distribution and mode of occurrence of Au within arsenian pyrite were investigat...

Reaction-induced porosity is a key factor enabling protracted fluid-rock interactions in the Earth's crust, promoting large-scale mineralogical changes during diagenesis, metamorphism, and ore formation. Here, we show experimentally that the presence of trace amounts of dissolved cerium increases the porosity of hematite (Fe 2 O 3) formed via fluid...

Even low levels of lead (Pb) contamination result in significant disruption to the surrounding ecology as Pb accumulates in soils and water and can be taken up by plants, which are then consumed by higher order animals. Understanding how Pb partitions between solids and the aqueous phase underpins prediction of bioavailability and locales of high t...

Kamchatka is a peninsula located on the far eastern side of Russia and is a geologically active region within the Pacific Ring of Fire. Placer gold particles were obtained from a stream located in the Yelizovsky District and were compared to particles from regions at similar latitudes. Russian gold particle surface textures and morphologies were ch...

Chalcopyrite, galena, and sphalerite commonly coexist with pyrite in sulfidic waste rocks. The aim of this work was to investigate their impact, potentially by galvanic interaction, on pyrite oxidation and acid generation rates under simulated acid and metalliferous drainage conditions. Kinetic leach column experiments using single-minerals and pyr...

At present, a significant portion of rare-earth elements (REEs) are sourced from weathering profiles. The mineralogy of the protolith plays an important role in controlling the fate of REEs during weathering, as accessory minerals contain the bulk the REE budget in most rocks, and different minerals vary in their susceptibilities to weathering proc...

We explore the role of various solution environments – chloride brines, acid mine drainage (sulfate) and groundwater (carbonate), as well as pore pressure in producing secular disequilibrium among the various radionuclides (RN) in the U-decay series upon leaching of uraninite – the most abundant U-ore and a widespread accessory mineral in U-rich ro...

Scapolite is abundant in medium to high grade metamorphic rocks with evaporitic calc-silicate bulk compositions, and because it can be Cl⁻ and SO4²⁻ rich, is able to provide a unique view into the evolution of deep brines during orogenic cycles. In the Zhongtiao Mountains, part of the Trans-North China Orogen (TNCO), scapolite occurs in two distinc...

The ability of aluminium-phosphate-sulfate (APS) phases to preferentially sorb lead and its radionuclides, particularly ²¹⁰Pb, from metallurgical processing streams has been recently recognised empirically. This suggests that APS minerals may be suitable for the removal of lead from environmental and anthropogenic processes. We investigated the Pb...

Reactive fluid flow can control the mineralogical, mechanical and chemical evolution of the Earth’s crust. When rocks are exposed to differential stresses (i.e., vertical stress ≠ horizontal stress ≠ pore-fluid pressure (Pf)) during reactive fluid flow, effective pressure is usually assumed to control the overall reaction process. Here, we show tha...

Anthropogenic activities can redistribute the constituents of naturally occurring radioactive materials (NORM), posing potential hazards to populations and ecosystems. In the present study, the co-sorption of several RN from the U decay chain– ²³⁸U, ²³⁰Th, ²²⁶Ra, ²¹⁰Pb and ²¹⁰Po, onto common minerals associated with mining activities (chalcopyrite,...

Knowledge of the behavior of technologically enhanced naturally occurring radioactive materials derived through the decay of U and its daughter products, and their subsequent fractionation, mobilization and retention, is essential to develop effective mitigation strategies and long-term radiological risk prediction. In the present study, multiple s...

Sulphur is the third most abundant volatile element in deep Earth systems. Analytical methods for accurately and efficiently determining the sulphur content and oxidation state in natural minerals are still lacking. Natural apatite is widely distributed in the Earth and incorporates a large amount of sulphur. Therefore, apatite is an ideal mineral...

The evolution of hydrothermal fluids during metasomatic and/or hydrothermal processes is responsible for the formation of ore deposits and associated alteration. In systems with well-developed breccia and fractures, mineral reactions are largely driven by decompression boiling, fluid cooling or external fluid mixing, but in less permeable rocks, el...

Knowledge of the identity and thermodynamic properties of aqueous molybdenum (Mo) species at elevated temperatures and pressures is important for understanding the extraction of Mo from source rocks and the formation of hydrothermal deposits. Chlorine and sulfur are two major components in crustal fluids. Several studies have investigated Mo specia...

In clean production of copper sulphide concentrate, both radioactive ²¹⁰Pb and nonradioactive Pb isotopes are dissolved into HCl solution, while Cu from copper concentrate product is also leached into the same solution. Herein, a new polyamine anion resin – Lewatit A365 – has been employed to selectively remove the trace amounts of Pb(II) from Cu(I...

The regolith is an important host for economic concentrations of critical metals such as REE, U, Ni, and Co. The (bio)geochemical weathering of rocks from ore deposits is a key process behind these supergene enrichments. The Flinders Ranges in South Australia is a natural laboratory to study REE and U mobility under (bio)geochemical weathering cond...

Placer gold particles are progressively transformed through (bio)geochemical processes under near-surface weathering environments. Previous studies have focused on Au biogeochemical cycling from particles obtained from “pristine” environments. The structure and chemistry of gold particles have been used to interpret past biogeochemical processes co...

Frank Reith: The Man with the Gold Bug - Allan Pring, Joël Brugger, Jeremiah Shuster

The gradual decrease of global copper resources is among the most urgent challenges for the mining industry. Sustainable utilization of copper sulphide flotation concentrate from iron oxide copper gold (IOCG) deposits is often constrained by the impurity elements (e.g. U, Th and F) and high levels of gangue minerals (e.g. iron oxide/hematite, U-bea...

IOCG deposits are economically important providing amongst other resources, around 12% of global copper production and 47% of Australian copper production. A number of different genetic models have been proposed for the formation of IOCG deposits including ore systems for which fluids and metals are sourced from igneous bodies (Hauck, 1990; Groves...

The HighPGibbs program is designed to calculate thermodynamic equilibrium of fluid‐rock systems up to depths of lithospheric mantle. It uses the Gibbs free energy minimization function of the HCh package to calculate mineral‐fluid equilibrium. Chemical potentials of minerals are calculated using the equations of states included in HCh; free energy...

Extensive use of the rare earth elements (REEs, mostly represented by the lanthanide group from La to Lu) in renewable energy applications and defense‐related technologies triggered high and growing interest to the processes responsible for migration, separation, and concentration of these elements in natural processes. Understanding these processe...

The Golden Mile deposit (1767 t Au) in the Archean Yilgarn Craton, Western Australia, is controlled by D2 strike-slip and D3 reverse faults displacing folded tholeiitic greenstones. Granodiorite and monzodiorite dykes emplaced into the faults predate and are synchronous with propylitic and sericite–ankerite alteration overprinted by the ore. Arseno...

Accurate knowledge of rare earth elements (REE) speciation in high pressure – high temperature fluids is required to model REE transport and precipitation in subduction zones and magmatic-hydrothermal environments, and the formation of rare metal deposits. Recent experiments (lanthanum, ytterbium, erbium) have demonstrated that REE chloride complex...