Browsing by Author "Paterson, DJ"

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    Bioaugmentation with Acidithiobacillus species accelerates mineral weathering and formation of secondary mineral cements for hardpan development in sulfidic Pb-Zn tailings
    (Elsevier, 2021-06) Liu, Y; Wu, S; Southam, G; Chan, TS; Lu, YR; Paterson, DJ; Huang, L
    The development of hardpan caps has great potential in rehabilitating sulfidic and metallic tailings, which may be accelerated by using exogenous Acidithiobacillus species. The present study aims to establish a bioaugmentation process with exogenous Acidithiobacillus species for accelerating the weathering of sulfidic minerals and formation of secondary mineral gels as precursors for hardpan structure development in a microcosm experiment. Exogenous Acidithiobacillus thiooxidans (ATCC 19377) and A. ferrooxidans (DSM 14882) were inoculated in a sulfidic Pb-Zn tailing containing negligible indigenous Acidithiobacillus species for accelerating the weathering of pyrite and metal sulfides. Microspectroscopic analysis revealed that the weathering of pyrite and biotite-like minerals was rapidly accelerated by exogenous Acidithiobacillus species, leading to the formation of secondary jarosite-like mineral gels and cemented profile in the tailings. Meanwhile, approximately 28% Zn liberated from Zn-rich minerals undergoing weathering was observed to be re-immobilized by Fe-rich secondary minerals such as jarosite-like mineral. Moreover, Pb-bearing minerals mostly remained undissolved, but approximately 30% Pb was immobilized by secondary Fe-rich minerals. The present findings revealed the critical role of exogenous Acidithiobacillus species in accelerating the precursory process of mineral weathering and secondary mineral formation for hardpan structure development in sulfidic Pb-Zn tailings. © 2020 Elsevier B.V.
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    Cooper Basin REM gas shales after CO2 storage or acid reactions: metal mobilisation and methane accessible pore changes
    (Elsevier, 2023-05-15) Pearce, JK; Blach, T; Dawson, GKW; Southam, G; Paterson, DJ; Golding, SD; Bahadur, J; Melnichenko, YB; Rudolph, V
    Shale - water - CO2 reactions may occur during CO2 geological storage, enhanced gas recovery, enhanced oil recovery, or supercritical CO2 fracturing. Shale-acid reactions occur during fracturing or acid stimulation. The mobilisation of metals from these processes can be an environmental concern if production water leaks or is released at surface. In addition, reactions may cause changes at the pore scale and affect gas or fluid flow. Three gas shales from the Australian Cooper Basin REM sequence were characterised for metals in minerals by synchrotron X-ray fluorescence microscopy. Metals including Zn, As, Ni, Cr were hosted in sphalerite associated with organic matter, Pb was in pyrite cement, and Mn was hosted in siderite. The shales were separately reacted with brine and supercritical CO2, with CO2-SO2, with dilute HCl, or with N2 at 100 °C and 20 MPa in batch reactors. The solution pH decreased during mineral reactions releasing metals to solution with the general concentrations from reaction with HCl > CO2-SO2 > CO2 > N2 and brine. Of the total available Pb, As, Li, and Zn in the shales, from 0 to 17%, 0.3 to 23%, 3 to 13%, and 0.4 to 28% was released to solution respectively. Corrosion of siderite and ankerite was observed after the CO2 reactions, with precipitation of Fe-oxides. After CO2-SO2 reaction siderite and ankerite were dissolved with pyrite, barite, and Fe-rich precipitates. HCl reactions resulted in complete dissolution of carbonates, with dissolution pits and no mineral precipitation observed. The changes to the fractions of gas accessible mesopores were characterised by small angle neutron scattering (SANS). The Epsilon Formation had the greatest fraction of open accessible pores in the SANS range of 10 to 150 nm, followed by the Murteree and Roseneath shale samples. After CO2 or CO2-SO2 reactions a small decrease in pore accessibility was more pronounced in the Murteree and Roseneath shales, consistent with mineral precipitation. HCl reaction resulted in opening of pores at 150 nm and closing of the smallest measured pores at 10 nm. Metals were mobilised from siderite, ankerite and sulphide minerals mainly, and were dependent on the mineral and metal content but also on the injected gas stream or fluid composition. CO2 based fluids may result in cleaner flow back water, than HCl based fluids. Geochemical reactions during CO2 storage or acid treatment in reactive shales cause pore changes that can affect gas migration. Mineral precipitation during CO2 and CO2-SO2 reactions can result in favourable self-sealing. © 2023 The Authors. Published by Elsevier B.V. Open Access - CC-BY.
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    The critical role of bacteria in mineral carbonation of kimberlite
    (Goldschmidt, 2022-07-12) Jones, TR; Poitras, J; Senzani, K; Ndlovu, S; Vietti, A; Paterson, DJ; Wilson, SA; Southam, G
    The breakdown of ultramafic rock during natural weathering captures carbon dioxide from the atmosphere to form carbonate minerals. Kimberlite, an ultramafic rock that can produce diamond weathers when exposed to water. These water-rock interactions also contribute to the growth of bacteria, which accelerate the weathering process. Yellow ground (oxidized Kimberlite found at the surface) samples from the South African Voorspoed and Kareevlei mines contained both molecular signatures (16SrDNA) and viable bacteria. Our molecular analyses highlighted a bacterial population consistent with serpentinite soils and demonstrated that bacteria play a role in yellow ground formation. These yellow ground cultures can grow using only kimberlite as a substrate, promoting weathering in order to live, and providing cultures that are important to natural weathering, yellow ground formation and subsequent mineral carbonation. In order to demonstrate the importance of biology in mineral carbonation of kimberlite, we performed X-Ray Fluorescent Microscopy (XFM) at the Australian Synchrotron to obtain structural and compositional analysis of the South African Venetia mine’s massive volcaniclastic kimberlite (MVK) Coarse Residue Deposit (CRD) with and without biofilm (weathering), 50-year-old Cullinan CRD and definitive, friable Kareevlei yellow ground. These analyses demonstrated that calcium, potassium and iron can be used as tracers for weathering and mineral carbonation. Our small laboratory and larger (1000 L) field-based mineral carbonation experiments both demonstrated the importance of photosynthetic biofilms in the carbonation of kimberlite residue. All of our experiments produced intergranular cements, which stabilised the CRD residue, providing a strategy to increase mine safety while sequestering carbon. We observed continued mineral carbonation with depth demonstrating that carbonation will continue as the kimberlite is buried on the mine site, which will achieve even greater carbon offsets than anticipated. Our pilot scale field experiment demonstrated that we offset 20% (on a mass equivalent) of the annual mine emissions in one year using bacterial carbonation, with the likelihood of continued carbonation ensuring that we will have the capacity to produce a carbon neutral mine.
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    Direct imaging of endogenous biometal distributions within millimetre-scale organisms at micrometre resolution – x-ray fluorescence tomography
    (Australian Microscopy and Microanalysis Society, 2016-02-04) de Jonge, MD; Ruben, G; Mayo, SS; Ryan, CG; Kirkham, R; Howard, DL; Paterson, DJ
    First-row transition metals are required for all forms of life on earth. The high reactivity of these elements means that an array of mechanisms has evolved to regulate key processes governing their transport and binding action. Tracking metals within biological tissue is non-trivial; tagging approaches suffer from lack of specificity, and can fail to find strongly-bound species; in addition, tags can interfere with normal biochemistry. Electron microscopy provides stupendous resolution, but probes miniscule volumes due to the short penetration of electrons. With μM sensitivity, X-ray Fluorescence Microscopy (XFM) can probe endogenous metal concentrations at resolutions at the μm length scale. Elemental maps are quantitative. With penetration depth and depth of field well matched at around 0.5 mm, the method can be up-scaled to 3-D visualisations via tomography. Here we report on our application of X-ray fluorescence tomography of Zn, Cu, Fe, and Mn in C. elegans and discuss recent progress in developing self-absorption corrections that will enable accurate mapping of light elements.
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    Effect of silicon on the distribution and speciation of uranium in sunflower (Helianthus annuus)
    (Elsevier, 2024-10) Wang, LL; Laing, Y; Liu, S; Chen, F; Wang, JG; Chen, YL; Paterson, DJ; Kopittke, PM; Wang, YH; Liu, C; Ye, Y
    Sunflower (Helianthus annuus) can potentially be used for uranium (U) phytoremediation. However, the factors influencing the absorption of U and its subsequent distribution within plant tissues remain unclear, including the effect of silicon (Si) which is known to increase metal tolerance. Here, using hydroponics, the effect of Si on the distribution and speciation of U in sunflower was examined using synchrotron-based X–ray fluorescence and fluorescence-X-ray absorption near-edge spectroscopy. It was found that ∼88 % of U accumulates within the root regardless of treatments. Without the addition of Si, most of the U appeared to bind to epidermis within the roots, whereas in the leaves, U primarily accumulated in the veins. The addition of Si alleviated U phytotoxicity and decreased U concentration in sunflower by an average of 60 %. In the roots, Si enhanced U distribution in cell walls and impeded its entry into cells, likely due to increased callose deposition. In the leaves, Si induced the sequestration of U in trichomes. However, Si did not alter U speciation and U remained in the hexavalent form. These results provide information on U accumulation and distribution within sunflower, and suggest that Si could enhance plant growth under high U stress. © 2024 Elsevier B.V.
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    Genetic biofortification of wheat with zinc: opportunities to fine‐tune zinc uptake, transport and grain loading
    (Wiley, 2021-12-30) Kamaral, C; Neate, SM; Gunasinghe, N; Milham, PJ; Paterson, DJ; Kopittke, PM; Seneweera, S
    Zinc (Zn) is an important micronutrient in the human body, and health complications associated with insufficient dietary intake of Zn can be overcome by increasing the bioavailable concentrations in edible parts of crops (biofortification). Wheat (Triticum aestivum L) is the most consumed cereal crop in the world; therefore, it is an excellent target for Zn biofortification programs. Knowledge of the physiological and molecular processes that regulate Zn concentration in the wheat grain is restricted, inhibiting the success of genetic Zn biofortification programs. This review helps break this nexus by advancing understanding of those processes, including speciation regulated uptake, root to shoot transport, remobilisation, grain loading and distribution of Zn in wheat grain. Furthermore, new insights to genetic Zn biofortification of wheat are discussed, and where data are limited, we draw upon information for other cereals and Fe distribution. We identify the loading and distribution of Zn in grain as major bottlenecks for biofortification, recognising anatomical barriers in the vascular region at the base of the grain, and physiological and molecular restrictions localised in the crease region as major limitations. Movement of Zn from the endosperm cavity into the modified aleurone, aleurone and then to the endosperm is mainly regulated by ZIP and YSL transporters. Zn complexation with phytic acid in the aleurone limits Zn mobility into the endosperm. These insights, together with synchrotron‐X‐ray‐fluorescence microscopy, support the hypothesis that a focus on the mechanisms of Zn loading into the grain will provide new opportunities for Zn biofortification of wheat. © 2021 Scandinavian Plant Physiology Society.
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    Germanium speciation in experimental and natural sphalerite: Implications for critical metal enrichment in hydrothermal Zn-Pb ores
    (Elsevier, 2023-02-01) Liu, WH; Mei, Y; Etschmann, BE; Glenn, M; MacRae, CM; Spinks, SC; Ryan, CG; Brugger, J; Paterson, DJ
    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 ± Ba-bearing brine with calcite and reduced sulfur at 200 °C and water vapor-saturated pressure. The products were examined using backscattered electron (BSE) imaging, electron probe microanalysis (EPMA), electron backscattered diffraction (EBSD), synchrotron X-ray fluorescence (SXRF) and micro-X-ray absorption near-edge structure (μ-XANES). We show that Ge(IV) is incorporated into sphalerite and bonded with reduced sulfur, both in the experimental sphalerite and in natural zinc ore samples from the MacArthur River Zn-Pb-Ag deposits, Australia. Copper K-edge XANES spectra show that copper occurs as Cu(I) in the experimental sphalerite, consistent with previous studies on Cu in natural sphalerite. The experiments reveal that Ge(IV) substitution in sphalerite occurs with and without the presence of other metal ions (e.g., Cu(I)), indicating that Ge(IV) substitution can be accommodated via charge balance by vacancies as well as by coupled substitution in the synthesized sphalerite. Ab initio quantum chemical simulations confirm that sphalerite can readily accommodate Ge via charge balance by vacancies and by coupled substitutions, with the crystal structure and average Zn-S, Zn-Zn, S-S distances retained when replacing > 3 mol% of the Zn sites with Ge(IV), Ge(II), Cu(I) or Fe(II), demonstrating the resilience and flexibility of the sphalerite crystal structure. These Ge incorporation mechanisms explain the previous observations of multiple ways of Ge incorporation in natural sphalerite. The study provides experimental and molecular simulation insights for understanding the processes related to the formation and extraction of Ge in zinc ores. 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-NDlicense
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    Habitat-specific allocations of elements in Atriplex lentiformis seeds indicate adaptation to metal toxicity
    (Oxford University Press, 2024-05-18) Murawska-Wlodarczyk, K; van der Ent, A; Wlodarczyk, T; Słomka, A; Paterson, DJ; Brueckner, D; Przybyłowicz, WJ; Mesjasz-Przybyłowicz, J; Ryan, CC; Maier, RM; Babst-Kostecka, A
    Self-sustaining vegetation in metal-contaminated areas is essential for rebuilding ecological resilience and community stability in degraded lands. Metal-tolerant plants originating from contaminated post-mining areas may hold the key to successful plant establishment and growth. Yet, little is known about the impact of metal toxicity on reproductive strategies, metal accumulation, and allocation patterns at the seed stage. Our research focused on the metal tolerant Atriplex lentiformis. Specifically, we examined the effects of toxic metal(loid) concentration in soils on variability in its reproductive strategies, including germination patterns, elemental uptake, and allocation within the seeds. We employed advanced imaging techniques like synchrotron X-ray fluorescence microscopy (2D scans and 3D tomograms) combined with inductively coupled plasma mass spectrometry to reveal significant differences in metal(loid) concentration and distribution within the seed structures of A. lentiformis from contrasting habitats. Exclusive Zn hotspots of high concentrations were found in the seeds of the metallicolous accession, primarily in the sensitive tissues of shoot apical meristems and root zones of the seed embryos. Our findings offer novel insights into phenotypic variability and metal tolerance and accumulation in plants from extreme environments. This knowledge can be applied to enhance plant survival and performance in land restoration efforts. © The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved.
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    Historical diamond mine waste reveals carbon sequestration resource in kimberlite residue
    (Elsevier, 2023-02) Jones, TR; Poitras, J; Paterson, DJ; Southam, G
    Mined sub-aerially stored kimberlite provided a natural laboratory in which to examine the potential for carbon sequestration in ultramafic materials. A 15 cm hand sample of ∼50-year-old ‘cemented’ coarse residue deposit (CRD) collected from a cemented surface layer in the Cullinan Diamond Mine tailings in Gauteng, South Africa, demonstrated the encouraging effects of weathering on mineral carbonation of kimberlite. The examination of petrographic sections using light microscopy, X-ray fluorescence microscopy (XFM) and backscatter electron – energy dispersive spectroscopy demonstrated that weathering produced extensive, secondary Ca/Mg carbonates that acted as an inter-granular cement, increasing the competency of the CRD, i.e., producing a hand sample. Nearly every grain in the sample, including primary, un-weathered angular carbonate clasts were coated in secondary, μm- to mm-scale carbonate layers, which are interpreted as secondary materials. DNA analysis of an internal, aseptic sample of secondary carbonate revealed that the weathered kimberlite hosts a diverse microbiome consistent with soils, metal cycling and hydrocarbon degradation that was found within the secondary carbonate, interpreted as a biomaterial. The formation of secondary carbonate demonstrates that ‘waste kimberlite’ from diamond mining can serve as a resource for carbon sequestration. © 2022 Elsevier B.V.
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    Impure CO2 storage reactions of sandstone, mudstone and carbonate cemented cores: xxperimental CO2 SO2 NOX O2 reaction metal mobilisation and fate
    (Elsevier, 2023-09-01) Pearce, JK; Dawson, GW; Brink, F; Southam, G; Paterson, DJ; Hall, N; Heath, R; Greer, D; Kirste, D; Golding, SD
    CO2 geological storage can be part of the solution to reduce carbon emissions to the atmosphere. An understanding of the geochemical processes occurring during CO2 storage is needed to reduce risk. Drill cores from a low salinity reservoir site proposed for CO2 storage, and the overlying and underlying formations, were characterised for minerals by QEMSCAN, total metals and porosity. Elements including Li, Ba, Sr, K, Mg, V, Zn, REE, Fe, Pb, P, and S were relatively elevated in the Moolayember Formation underlying the reservoir. Synchrotron XFM showed the main host of Mn was siderite, with Rb in K-feldspar, Zn and Cu in sphalerite and chalcopyrite, and As in pyrite in coal pores associated with coal laminations. Drill cores are reacted at reservoir conditions with synthetic formation water and an impure CO2 stream composition of CO2-SOx-NOx-O2 expected to be injected at the site. Elements released were dependant on mineral content, with quartz rich reservoir, lower Precipice Sandstone core reactions resulting in dissolution of trace carbonates, alteration of sulphides and monazite, and variable elevated dissolved Pb, and U. Dissolved Co, Ni, Ca, Zn, Li, Rb, and U were released at relatively elevated concentrations from the mudstone. For carbonate cemented upper Precipice Sandstone or Moolayember Formation core strong dissolution of calcite and ankerite, with corrosion of siderite, Fe-rich chlorite, and sulphides or monazite were observed after reaction. Dissolved elements including Ca, Mg, Mn, Sr, and Ba increased in experiments from the reaction of calcite, siderite, and ankerite. Generally dissolved Fe, Pb, Cr, Cu, Co etc. increased from dissolution, and subsequently decreased in concentration with adsorption and precipitation processes. The fast mobilisation of elements including Fe and Pb are consistent with the release of metals from carbonate dissolution and desorption. The presence of O2 and NOX in the gas stream results in Fe-(oxyhydr)oxide precipitation especially where Fe has been rapidly mobilised from dissolution of siderite and Fe-chlorite. This acts as a sink for Fe and provides new adsorption sites for sequestering a proportion of the trace metals. These processes are applicable to other CO2 storage sites and potential leakage indicators in overlying drinking water aquifers. The findings are also more broadly applicable to subsurface energy storage such as compressed air renewable energy storage, CO2 enhanced recovery, geothermal, natural gas or hydrogen storage. © 2023 The Authors. Published by Elsevier B.V. - Open Access CC-BY.
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    Mechanisms of murine cerebral malaria: multimodal imaging of altered cerebral metabolism and protein oxidation at hemorrhage sites
    (American Association for the Advancement of Science, 2015-12-18) Hackett, MJ; Aitken, JB; El-Assaad, F; McQuillan, JA; Carter, EA; Ball, HJ; Tobin, MJ; Paterson, DJ; de Jonge, MD; Siegele, R; Cohen, DD; Vogt, S; Grau, GE; Hunt, NH; Lay, PA
    Using a multimodal biospectroscopic approach, we settle several long-standing controversies over the molecular mechanisms that lead to brain damage in cerebral malaria, which is a major health concern in developing countries because of high levels of mortality and permanent brain damage. Our results provide the first conclusive evidence that important components of the pathology of cerebral malaria include peroxidative stress and protein oxidation within cerebellar gray matter, which are colocalized with elevated nonheme iron at the site of microhemorrhage. Such information could not be obtained previously from routine imaging methods, such as electron microscopy, fluorescence, and optical microscopy in combination with immunocytochemistry, or from bulk assays, where the level of spatial information is restricted to the minimum size of tissue that can be dissected. We describe the novel combination of chemical probe–free, multimodal imaging to quantify molecular markers of disturbed energy metabolism and peroxidative stress, which were used to provide new insights into understanding the pathogenesis of cerebral malaria. In addition to these mechanistic insights, the approach described acts as a template for the future use of multimodal biospectroscopy for understanding the molecular processes involved in a range of clinically important acute and chronic (neurodegenerative) brain diseases to improve treatment strategies. 2015 © The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution Non Commercial Licence 4.0 (CC BY-NC).
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    Mechanisms of uptake and translocation of thallium in brassica vegetables: an x‑ray fluorescence microspectroscopic investigation
    (American Chemical Society, 2024-01-02) Corzo-Remigio, A; Harris, HH; Kidman, CJ; Nkrumah, PN; Casey, LW; Paterson, DJ; Edraki, M; van der Ent, A
    Most nonoccupational human exposure to thallium (Tl) occurs via consumption of contaminated food crops. Brassica cultivars are common crops that can accumulate more than 500 μg Tl g–1. Knowledge of Tl uptake and translocation mechanisms in Brassica cultivars is fundamental to developing methods to inhibit Tl uptake or conversely for potential use in phytoremediation of polluted soils. Brassica cultivars (25 in total) were subjected to Tl dosing to screen for Tl accumulation. Seven high Tl-accumulating varieties were selected for follow-up Tl dosing experiments. The highest Tl accumulating Brassica cultivars were analyzed by synchrotron-based micro-X-ray fluorescence to investigate the Tl distribution and synchrotron-based X-ray absorption near-edge structure spectroscopy (XANES) to unravel Tl chemical speciation. The cultivars exhibited different Tl tolerance and accumulation patterns with some reaching up to 8300 μg Tl g–1. The translocation factors for all the cultivars were >1 with Brassica oleracea var. acephala (kale) having the highest translocation factor of 167. In this cultivar, Tl is preferentially localized in the venules toward the apex and along the foliar margins and in minute hot spots in the leaf blade. This study revealed through scanning electron microscopy and X-ray fluorescence analysis that highly Tl-enriched crystals occur in the stoma openings of the leaves. The finding is further validated by XANES spectra that show that Tl(I) dominates in the aqueous as well as in the solid form. The high accumulation of Tl in these Brassica crops has important implications for food safety and results of this study help to understand the mechanisms of Tl uptake and translocation in these crops. © 2024 American Chemical Society
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    Micro-scale dissolution seams mobilise carbon in deep-sea limestones
    (Springer Nature, 2021-08-27) Schrank, CE; Jones, MMW; Kewish, CM; van Riessen, GA; Elphick, KE; Sloss, CR; Nothdurft, LD; Webb, GE; Paterson, DJ; Regenauer-Lieb, K
    Measuring the amount of carbon captured in deep-sea limestones is fundamental to understanding the long-term carbon cycle because pelagic limestones represent Earth’s largest carbon sink since the mid-Mesozoic. However, their contribution to the long-term carbon cycle is poorly quantified. Here, we use X-ray fluorescence and scanning X-ray diffraction microscopy for high-resolution chemical and structural analysis of pelagic limestone from the Paleocene Kaiwhata Formation in New Zealand. We identify densely packed diagenetic micro-dissolution seams that are invisible to light and electron-beam microscopes in most cases. Mass-balance calculations indicate that individual seams remove ~50% of the calcite mud matrix while their bulk-sample carbon loss adds up to ~10%. The liberated carbon is trapped in situ as calcite cement or returned to the ocean during physical compaction or soft-sediment deformation. We suggest micro-dissolution structures may play an important role in the long-term carbon cycle by modulating carbon exchange between the geosphere and hydrosphere. © 2024 The Authors - Open Access - CC-BY 4.0
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    Microspectroscopy beamline at the Australian Synchrotron
    (American Institute of Physics, 2007-01-19) Paterson, DJ; Boldeman, JW; Cohen, DD; Ryan, CG
    This dedicated beamline will provide sub‐micron spatial resolution with the highest flux possible and an energy tuning range of 4.7–25 keV using an in‐vacuum undulator source. It will combine 2D mapping with μ‐XRF, μ‐XANES and μ‐XAFS for elemental and chemical analysis to solve scientific problems that can only be understood using sub‐micron resolutions. The primary beamline design goal is to achieve sub‐micron spatial resolution, 100–200 nm, at energy resolutions approaching 1/10000. This spatial resolution will be achieved without a major compromise to the flux, as the beamline will simultaneously achieve detection sensitivities to sub‐ppm levels. The beamline will have the flexibility to trade‐off one parameter against gains in certain attributes, as dictated by the needs of the application. Fresnel zone plates are intended for the highest resolution applications, while the KB mirrors are shall be used for applications where achromatic focusing and high sensitivity are required. The beamline design will accommodate a diverse range of applications with greatly contrasting sample formats, sample composition and anticipated detector count rates. © 2007 American Institute of Physics.
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    Microspectroscopy beamline at the Australian synchrotron: design and capabilities
    (XRM Conference, 2008-07) Paterson, DJ; de Jonge, MD; McKinlay, J; Ryan, CG; Cohen, DD
    A hard x-ray micro-nanoprobe is being constructed at the Australian Synchrotron [1] to provide sub-micron spatial resolution across an energy range of 4.5–25 keV. The SXM will combine 2D mapping with μ-XRF, μ-XANES and μ-XAFS for elemental and chemical microanalysis. The primary design goal is to achieve sub-100 nm spatial resolution with DE/E ~10-4, and sub-ppm elemental sensitivity. The optical design is a novel “all horizontal” scheme [2]. Interchangeable Fresnel zone plates and Kirkpatrick-Baez mirrors will be used. An advanced fluorescence detector developed by BNL [3] and CSIRO [4] featuring a large solid-angle planar silicon array will enable count rates up to 108 events/sec and real-time processing with deconvoluted image projection. A differential phase contrast detection scheme [5] will be employed for quantitative measurement of soft matter [6]. The Microspectroscopy Beamline will commence operation in late 2008 and will accommodate a diverse range of environmental, biological and materials science applications to cater for the broad requirements of the Australian community. The design, anticipated performance and research applications will be discussed.
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    Nickel exchange between aqueous Ni(II) and deep-sea ferromanganese nodules and crusts
    (Elsevier, 2019-12-05) Hens, T; Brugger, J; Etschmann, BE; Paterson, DJ; Brand, HEA; Whitworth, AJ; Frierdich, AJ
    Deep-sea ferromanganese (Fe-Mn) nodules and crusts are rich in traditional and non-traditional metals with both current and emerging economic value. Mn(III,IV) oxides (e.g., phyllomanganates) are important host phases for these metals (e.g., Ni), which are structurally incorporated during nodule and Fe-Mn crust formation. Recrystallization of phyllomanganates can be catalyzed by aqueous Mn(II) (Mn(II)aq) during (bio)geochemical Mn redox cycling. The fate of structurally incorporated metals during such recrystallization of Mn(III,IV) oxides remains, however, poorly constrained. Here, we use a 62Ni isotope tracer to determine the exchangeability of dissolved Ni with structurally incorporated Ni in two deep-sea Fe-Mn nodules and one Fe-Mn crust. Ni exchange between solid and solution was investigated during reactions in 1 mM Mn(II)aq and in Mn(II)-free solutions under variable pH conditions (pH 5.5 and 7.5) over time. Sample characterization shows that all samples are of hydrogenetic or mixed hydrogenetic-diagenetic origin and Ni is preferentially associated with the phyllomanganates. Our Ni exchange experiments reveal that in some samples up to 25% of incorporated Ni is exchangeable with the fluid after 14 days. The prevalent reaction pathways exhibit pH-dependent behavior during phyllomanganate recrystallization and differ between sample types, with Mn(II)aq enhancing Ni exchange in the Fe-Mn crust-fluid system and Ni exchange being independent of Mn(II)aq concentrations in the Fe-Mn nodule-fluid systems. The exchangeability of structurally-incorporated Ni in Fe-Mn nodules and crusts indicates a labile behavior that potentially makes it available for biogeochemical processes in the marine environment. © 2019 Elsevier B.V
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    Past fires and post-fire impacts reconstructed from a southwest Australian stalagmite
    (Australasian Quaternary Association (AQUA), 2021-07-09) McDonough, LK; Treble, PC; Baker, AA; Borsato, A; Frisia, S; Nagra, G; Coleborn, K; Gagan, MK; Fakra, SC; Paterson, DJ
    Stalagmites provide records of past changes in climate, vegetation, and surface events, with cave dripwaters shown to respond to fires. It is, therefore, most likely that these cave mineral deposits capture the environmental effects of palaeo-wildfires in their chemical and physical properties, as well as the climate conditions antecedent to palaeo-fire events. We analysed multiple proxies in stalagmite (YD-S2) from a shallow cave in south-west Western Australia. Principal Component Analysis revealed that short term peaks in combinations of phosphorus, copper, aluminium, lead and zinc in the stalagmite correspond to the timing of documented fire events occurring in the modern portion of the record. One particularly significant fire event is identified at 1897 ± 5 CE and shows a clear peak in P interpreted to be derived from ash, and a peak in 𝛿18O interpreted to indicate evaporation of sub-surface water during the heat of the fire. A post-fire threshold rise in organic matter content and a shift in calcite fabric associated with higher and more variable drip rates are consistent with a post-fire changes in surface-cave hydrology resulting from heat-induced deformation of the shallow karst bedrock brought about by the intensity of this fire. The combination of climate and fire sensitive proxies in YD-S2 indicates that the 1897 ± 5 CE wildfire was preceded by a multi-decadal dry period. We also identify lower and less variable peak phosphorus concentrations in the pre-European period that are consistent with low-intensity cultural burning by Indigenous Australians. The YD-S2 record shows the potential of stalagmites in capturing the climate-fire relationship and the effects of land-management practices on wildfire frequency and intensity.
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    Past fires and post-fire impacts reconstructed from a southwest Australian stalagmite
    (American Geophysical Union (AGU), 2021-12-17) McDonough, LK; Treble, PC; Baker, AA; Borsato, A; Frisia, S; Campbell, M; Nagra, G; Coleborn, K; Gagan, MK; Paterson, DJ
    Stalagmites provide records of past changes in climate, vegetation, and surface events, with cave dripwaters shown to respond to fires. It is, therefore, most likely that these cave mineral deposits capture the environmental effects of palaeo-wildfires in their chemical and physical properties, as well as the climate conditions antecedent to palaeo-fire events. We analysed multiple proxies in stalagmite (YD-S2) from a shallow cave in south-west Western Australia. Principal Component Analysis revealed that short term peaks in combinations of phosphorus, copper, aluminium, lead and zinc in the stalagmite correspond to the timing of documented fire events occurring in the modern portion of the record. One particularly significant fire event is identified at 1897 ± 5 CE and shows a clear peak in P interpreted to be derived from ash, and a peak in 𝛿18O interpreted to indicate evaporation of sub-surface water during the heat of the fire. A post-fire threshold rise in organic matter content and a shift in calcite fabric associated with higher and more variable drip rates are consistent with a post-fire changes in surface-cave hydrology resulting from heat-induced deformation of the shallow karst bedrock brought about by the intensity of this fire. The combination of climate and fire sensitive proxies in YD-S2 indicates that the 1897 ± 5 CE wildfire was preceded by a multi-decadal dry period. We also identify lower and less variable peak phosphorus concentrations in the pre-European period that are consistent with low-intensity cultural burning by Indigenous Australians. The YD-S2 record shows the potential of stalagmites in capturing the climate-fire relationship and the effects of land-management practices on wildfire frequency and intensity. Plain-language Summary Fires have the potential to be recorded in stalagmites as pulses of ash-derived elements that leach intro dripwater above the cave. These ash-derived elements can then be incorporated into stalagmites as they grow. We analysed a stalagmite from a shallow cave in south-west Western Australia which revealed increases in phosphorus and metals including copper, lead, aluminium and zinc during years when fires are documented to have occurred over the cave. We use peaks in these elements to extend the fire record back to the 1760’s and identify a particularly large fire event in 1897 ± 5. This fire event was intense enough to cause not only an increase in ash-derived elements, but also an increase in the transmission of rainfall between the surface and the cave due to fracturing of the limestone as a result of intense heating and cooling. This event occurred at the end of a known drought period and was likely enhanced by the dry conditions. We also identify evidence for lower-intensity cultural burning by Indigenous Australians in the pre-European period compared to the post-European period, suggesting that changes in land management may also be recorded in stalagmites.
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    Placental element content assessed via synchrotron-based x-ray fluorescence microscopy identifies low molybdenum concentrations in foetal growth restriction, postdate delivery and stillbirth
    (MDPI, 2024-08-03) Foteva, V; Maiti, K; Fisher, JJ; Qiao, Y; Paterson, DJ; Jones, MWM; Smith, R
    Placental health and foetal development are dependent upon element homeostasis. Analytical techniques such as mass spectroscopy can provide quantitative data on element concentrations in placental tissue but do not show spatial distribution or co-localisation of elements that may affect placental function. The present study used synchrotron-based X-ray fluorescence microscopy to elucidate element content and distribution in healthy and pathological placental tissue. The X-ray fluorescence microscopy (XFM) beamline at the Australian Synchrotron was used to image trace metal content of 19 placental sections from healthy term (n = 5, 37–39 weeks), foetal growth-restricted (n = 3, <32 weeks, birth weight <3rd centile), postdate (n = 7, >41 completed weeks), and stillbirth-complicated pregnancies (n = 4, 37–40 weeks). Samples were cryo-sectioned and freeze-dried. The concentration and distribution of fourteen elements were detected in all samples: arsenic, bromine, calcium, chlorine, copper, iron, molybdenum, phosphorous, potassium, rubidium, selenium, strontium, sulphur, and zinc. The elements zinc, calcium, phosphorous, and strontium were significantly increased in stillbirth placental tissue in comparison to healthy-term controls. Strontium, zinc, and calcium were found to co-localise in stillbirth tissue samples, and calcium and strontium concentrations were correlated in all placental groups. Molybdenum was significantly decreased in stillbirth, foetal growth-restricted, and postdate placental tissue in comparison to healthy-term samples (p < 0.0001). Synchrotron-based XFM reveals elemental distribution within biological samples such as the placenta, allowing for the co-localisation of metal deposits that may have a pathological role. Our pilot study further indicates low concentrations of placental molybdenum in pregnancies complicated by foetal growth restriction, postdate delivery, and stillbirth. © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
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    Predicted CO2 water rock reactions in naturally altered CO2 storage reservoir sandstones, with interbedded cemented and coaly mudstone seals
    (Elsevier, 2022-03-15) Pearce, JK; Dawson, GW; Golding, SD; Southam, G; Paterson, DJ; Brink, F; Underschultz, JR
    Geological storage of CO2 captured from industrial processes such as coal combustion or from direct air capture is part of the transition to low emissions. The Jurassic Precipice Sandstone of the southern Surat Basin, Queensland, Australia, is undergoing feasibility studies for industrial scale CO2 geological storage, however regional data has so far been lacking. Precipice Sandstone reservoir drill core samples from the Southwood 1 and Tipton 153 wells in the southern Surat Basin include favourably quartz rich sandstone regions with quartz grain fracturing. A mudstone layer is also present in the reservoir. The overlying lower section of the Evergreen Formation seals consist of clay rich sandstones, interbedded mudstones, coal layers, Fe-Mg-Mn siderite, and Mg-calcite cemented sandstones. K-feldspars are weathered creating localised secondary porosity and pore filling kaolinite and illite. Layers of coal, pore filling cements, and framework grain compaction introduce vertical heterogeneity. Heavy minerals including pyrite, mixed composition sulphides, and barite are associated with disseminated coals in mudstones. Precipice Sandstone mercury intrusion porosities (MIP) ranged from 9 to 22% with favourably low reservoir injection threshold pressures, and the QEMSCAN measured open porosity between 2 and 22%. Evergreen Formation seal porosities were 7.5 to 16% by MIP or 1 to 19% by QEMSCAN, with the smallest pore throat distribution associated with the low permeability coal rich mudstone. Synchrotron XFM shows Rb mainly hosted in K-feldspars and muscovite, with metals including Mn mainly hosted in siderite. Zn and As are present in sulphides; and calcite and apatite cements mainly hosted Sr. Twenty kinetic geochemical CO2-water-rock models were run for 30 and 1000 years with Geochemist Workbench, with calcite and siderite initially dissolving. In the Precipice Sandstone reservoir variable alteration of carbonates, feldspars and chlorite to kaolinite, silica, siderite and smectite were predicted with the pH remaining below 5.5. CO2 was mineral trapped through alteration of chlorite to siderite in three of the four cases, with −0.02 to 1.43 kg/m3 CO2 trapped after 1000 years. In the calcite and siderite cemented Evergreen Formation seal, plagioclase conversion to ankerite trapped the most CO2 with 2.6 kg/m3 trapped after 1000 years. The Precipice Sandstone in both wells appears to be generally suitable as a storage reservoir, with mineral trapping predicted to mainly occur in the overlying lower Evergreen Formation and in interbedded mudstones. Heterogeneity in interbedded sandstone, mudstone, and coal layers are likely to act as baffles to CO2 and encourage mineral trapping. Quartz grain fractures may influence preferential migration pathways in the reservoir but this would need future experimental investigation. Experimental CO2 water rock reactions to understand porosity and permeability changes were out of scope here but are recommended in future validation, along with investigating the potential for CO2 adsorption trapping in coal and mudstone layers. © 2022 Elsevier B.V. All rights reserved.