ORCID Profile
0000-0003-3259-7983
Current Organisation
University of Adelaide
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Geology | Geochronology | Marine and Estuarine Ecology (incl. Marine Ichthyology) | Ore Deposit Petrology | Basin Analysis | Igneous and Metamorphic Petrology | Tectonics | Isotope Geochemistry
Expanding Knowledge in the Earth Sciences | Mineral Exploration not elsewhere classified | Oil and Gas Exploration | Ecosystem Assessment and Management of Marine Environments |
Publisher: Elsevier BV
Date: 10-2022
Publisher: Oxford University Press (OUP)
Date: 2015
Abstract: The petrology, mineralogy and geochemistry of a section of the Merensky Reef at Bafokeng Rasimone Platinum Mine (BRPM) are described. A model for the formation of platinum-group minerals (PGM), sulphide and chromitite is proposed that explains the stratigraphic relationships observed in the Merensky Reef, both at BRPM and at other locations in the Bushveld Complex. To achieve this it is necessary to understand platinum-group element (PGE) behaviour in naturally occurring mafic systems and for this reason comparisons are drawn from core TN207 through the Platreef at Tweefontein. The common link between the Platreef and Merensky Reef is the presence of unusually high concentrations of As, Sb, Bi and Te that promote the crystallisation of semi-metal bearing PGM from sulphide liquids. Under conditions of increasing semi-metal contamination, Pt is the first PGE to be extracted from a sulphide liquid followed by Rh, Ru, Os and Ir. While some Pd is released to form Pd-PGM much of it remains within the Ni-rich sulphide phase that crystallizes to form pentlandite. A critical aspect is the timing of their introduction into the magmatic system. For the Merensky magmas, contamination occurred predominantly within a staging chamber owing to wall-rock interaction with Transvaal sediments. This led to the formation of sulphide liquids that captured PGE and, ultimately, the crystallization of Pt- and Ru-PGM. The extreme enrichment in PGE and the high Pt/Pd ratios in the Merensky chromitites are attributed to density-driven concentration of PGM transported by magmas displaced from a staging chamber. Emplacement of these magmas into the Bushveld Complex resulted in thermo-mechanical erosion of the floor and deposition of chromites + sulphides + PGM. In places, these assemblages collected in sedimentary-like scour channels. In the Platreef, contamination occurred largely after magma emplacement owing to interaction with the local Transvaal sediments. As a result, mechanical separation of PGM did not occur and most PGM remain spatially associated with their original sulphide hosts.The Merensky Reef is a prime ex le of highly efficient PGE concentration resulting from mechanical processes, whereas the Platreef is a prime ex le of highly efficient PGE removal from sulphide liquids in response to extreme contamination by semi-metals.
Publisher: Elsevier BV
Date: 08-2019
Publisher: Mineralogical Society
Date: 02-11-2021
DOI: 10.1180/MGM.2021.81
Abstract: Ancient metamorphic processes are recorded by the formation of metallic-Pb nanospheres in zircon, a product of internal Pb mobilisation and thermally driven concentration. Here, metallic-Pb nanospheres formed within an ore deposit are characterised for the first time using high-angle annular dark field scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy element-distribution mapping. Exceptional ex les from the migmatite-hosted Archean–Paleoproterozoic Challenger Au deposit (Central Gawler Craton, South Australia) support widespread metallic-Pb nanosphere formation in zircon from rocks experiencing granulite-facies metamorphism. We also report new trace-element associations found with metallic-Pb nanospheres and a new mode of occurrence, in which Sc ‘haloes’ form adjacent to metallic-Pb nanospheres within the crystalline zircon lattice. This differs to previously characterised ex les of metallic-Pb nanospheres associated with amorphous Si-rich glasses and unidentified Al–Ti, or Fe-bearing phases. Multiple modes of metallic-Pb nanosphere occurrences and trace-element associations suggests multiple modes of formation, probably dependant on zircon composition and metamorphic conditions. Identification of metallic-Pb nanospheres in a growing range of geological settings further highlights the mobility of Pb in zircon and the importance of detailed, nanoscale mineral characterisation, in order to constrain accurate geochronological histories for rocks within high-temperature geological environments.
Publisher: Elsevier BV
Date: 05-2022
Publisher: Frontiers Media SA
Date: 12-10-2022
DOI: 10.3389/FEART.2022.967189
Abstract: Hematite (α-Fe 2 O 3 ) and magnetite (Fe 3 O 4 ) readily accommodate a wide range of minor and trace elements from across the periodic table at up to wt.% concentrations. This prompts the question of whether these common minerals can also host rare earth elements (lanthanides, Y and Sc REEs)? If so, what is the chemical and physical nature of the elements: are they incorporated into the oxide crystal structures, or do they occur as nanometer-to micron-sized inclusions of discrete REE-minerals? By combining micron-scale petrography and analysis by LA-ICP-MS with nanoscale imaging and energy-dispersive spectroscopy, the relationships between REEs and iron-oxides are addressed in s les from the world-class Olympic Dam Cu-U-Au-Ag deposit, South Australia. Spatially co-existing silician magnetite and hematite from the outer shell at Olympic Dam show stages of interconversion during which REEs are redistributed. REEs are shown to be preferentially incorporated into the magnetite structure, whereas hematite concentrates U, W, and Sn, and contains negligible structurally bound REEs. Abundant, & nm-sized uraninite nanoparticles (NPs) are a key host for REEs in hematite. In contrast, hematite from mineralized breccias displays co-precipitation of Fe-oxides and REE-minerals facilitated by discharge of high-volatile fluids. Variation in the shape of chondrite-normalized REE fractionation trends, ranging from concave (hematite containing uraninite NPs) to steeply downwards-sloping (included LREE-dominant phases such as monazite, florencite, fluocerite and cerianite), reflect these differences. Evolving NP mineralogy in the breccias, from in-situ NP formation to an abundance of monazite reflects successive overprinting events and remobilization of elements from solid-solution and subsequent trapping as NPs via coupled dissolution replacement reaction. REE-minerals such as florencite can host nanoinclusions of hematite. Atomic-scale observations, including defects in magnetite and an O-deficient, two-fold hematite superstructure show crystal structural accommodation during Fe-oxide interconversion and inclusion nucleation. Both silician magnetite and hematite show nanoscale muscovite forming along planar defects. Understanding the mineralogical deportment of REEs at Olympic Dam carries potential implications for investigating the viability of REE extraction opportunities from any resource in which Fe-oxides are the dominant component.
Publisher: Springer Science and Business Media LLC
Date: 16-05-2018
Publisher: Elsevier BV
Date: 05-2019
Publisher: Society of Economic Geologists
Date: 08-2009
Publisher: MDPI AG
Date: 28-02-2021
DOI: 10.3390/NU13030800
Abstract: Imbalanced maternal micronutrient status, poor placentation, and oxidative stress are associated with greater risk of pregnancy complications, which impact mother and offspring health. As selenium, iodine, and copper are essential micronutrients with key roles in antioxidant systems, this study investigated their potential protective effects on placenta against oxidative stress. First trimester human placenta explants were treated with different concentrations of selenium (sodium selenite), iodine (potassium iodide), their combination or copper (copper (II) sulfate). The concentrations represented deficient, physiological, or super physiological levels. Oxidative stress was induced by menadione or antimycin. Placenta explants were collected, fixed, processed, and embedded for laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) element imaging or immunohistochemical labelling. LA ICP-MS showed that placenta could uptake selenium and copper from the media. Sodium selenite and potassium iodide reduced DNA damage and apoptosis (p 0.05). Following oxidative stress induction, a higher concentration of sodium selenite (1.6 µM) was needed to reduce DNA damage and apoptosis while both concentrations of potassium iodide (0.5 and 1 µM) were protective (p 0.05). A high concentration of copper (40 µM) increased apoptosis and DNA damage but this effect was no longer significant after induction of oxidative stress. Micronutrients supplementation can increase their content within the placenta and an optimal maternal micronutrient level is essential for placenta health.
Publisher: Elsevier BV
Date: 10-2012
Publisher: Geological Society of London
Date: 02-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6JA00395H
Abstract: The production rates of polyatomic oxygen interferents (MO + /M + ) during LA-ICP-MS analysis were investigated in a range of silicate materials and metals.
Publisher: Springer Science and Business Media LLC
Date: 22-06-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4JA00012A
Abstract: In this study we investigate the effect that the mineral composition has on the quantification of sulphur by Laser Ablation ICP-MS (LA-ICP-MS) between a range of sulphide minerals: pyrite, pyrrhotite, bornite, chalcopyrite, sphalerite, pentlandite and tetrahedrite.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Mineralogical Society of America
Date: 08-2012
DOI: 10.2138/AM.2012.4207
Publisher: MDPI AG
Date: 10-05-2023
DOI: 10.3390/MIN13050656
Abstract: The Mount Weld rare earth element (REE) deposit, Western Australia, is one of the largest of its type on Earth. Current mining exploits the high-grade weathered goethite-bearing resource that lies above, and which represents the weathering product of a subjacent carbonatite. The mineralogy, petrography, deportment of lanthanides among the different components, and variation in mineral speciation, textures, and chemistry are examined. Microanalysis, involving scanning electron microscope (SEM) imaging, electron probe microanalysis (EPMA) and laser ablation inductively coupled-plasma mass spectrometry (LA-ICP-MS), was conducted on sized fractions of three crushed and ground laterite ore s les from current and planned production, and a representative s le from the underlying carbonatite. High-magnification imaging of particles in laterite s les show that in idual REE-bearing phases are fine-grained and extend in size well below the micron-scale. Nanoscale inclusions of REE-phosphates are observed in apatite, Fe-(Mn)-(hydr)oxides, and quartz, among others. These have the appearance, particularly in fluorapatite, of pervasive, ultrafine dusty domains. Apart from the discrete REE minerals and abundant nano- to micron-scale inclusions in gangue, all ore components analysed by LA-ICP-MS contain trace to minor levels of REEs within their structures. This includes apatite, where low levels of REE are confirmed in preserved igneous apatite, but also Fe- and Mn-(hydr)oxides in which concentrations of hundreds, even thousands of ppm are measured. This is significant given that Fe-(Mn)-(hydr)oxides are the most abundant component of the laterite and points to extensive mobility and redistribution of REEs, and especially HREE, during progressive lateritisation. Late-formed minerals, notably tiny grains of cerianite, reflect a shift to oxidising conditions. REE-fluorocarbonates are the main host for REEs in carbonatite and are systematically replaced by hydrated, Ca-bearing REE-phosphates (largely rhabdophane). The latter displays varied compositions but is characteristically enriched in HREE relative to monazite in the same s le. Fine-grained, compositionally heterogeneous rhabdophane is accompanied by minor amounts of other paragenetically late, hydrated phosphates with enhanced MREE/HREE relative to LREE (although still LREE-dominant). Minor, relict xenotime and zircon are significant HREE carriers. Ilmenite and pyrochlore group members contain REE but contribute only negligibly to the overall REE budget. Although the proportions of in idual mineral species differ, the chemistry of key ore components are similar in different laterite s les from the current resource. Mineral signatures are, however, subtly different in the lower grade southeastern part of the deposit, including higher concentrations of HREE relative to LREE in monazite, rhabdophane, florencite and Fe-(Mn)-(hydr)oxides.
Publisher: Geological Society of America
Date: 12-05-2020
DOI: 10.1130/G47087.1
Abstract: The halogens Cl and Br are sensitive indicators for the origin of ore-forming fluids. Here, we use a combination of microchemical and microscopic methods to show that measurable concentrations of these elements commonly occur as atomic-scale substitutions in hydrothermal sphalerite. Furthermore, the Cl/Br ratios of halogen-rich sphalerites are indistinguishable from those of the corresponding ore-forming fluids. Thus, they record fluid compositions, which in turn record fluid origin. Given the abundance of sphalerite in hydrothermal base-metal deposits, as well as the relative ease of conducting in situ microchemical analyses, the halogen signature of sphalerite has the potential to become a sensitive proxy to distinguish between different ore-forming environments.
Publisher: Wiley
Date: 05-12-2021
DOI: 10.1111/GGR.12365
Publisher: Elsevier BV
Date: 07-2019
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 06-2018
Publisher: MDPI AG
Date: 05-07-2021
DOI: 10.3390/MIN11070728
Abstract: The Bukit Botol and Bukit Ketaya deposits are two ex les of volcanic-hosted massive sulphide (VHMS) deposits that occur in the Tasik Chini area, Central Belt of Peninsular Malaysia. The mineralisation is ided into subzones distinguished by spatial, mineralogical, and textural characteristics. The primary sulphide minerals include pyrite, chalcopyrite, sphalerite, and galena, with lesser amounts of Sn- and Ag-bearing minerals, with Au. However, pyrrhotite is absent from both deposits. This study presents the results of sphalerite chemistry analysed by using an electron microprobe. Two types of sphalerite are recognised: sphalerite from the Bukit Botol deposit reveals a range of DL to 24.0 mole% FeS, whereas sphalerite from the Bukit Ketaya deposit shows a range of DL to 3 mole% FeS. Significant variations are shown in Zn, Cu, Cd, and Ag levels. Although the sphalerite has a wide variation in composition, a discernible decreasing Fe trend is exhibited from the stringer zone towards massive sulphide. This compositional variation in sphalerites may in part reflect variable temperature and activity of sulphur in the hydrothermal fluids during ore formation. Alternatively, the bimodal composition variations suggest that mineral chemistry relates to contrasting depositional processes. The Zn/Cd ratios for sphalerite from both these deposits are similar to those exhibited by volcano−sedimentary deposits with a volcanic origin. Therefore, the consistently low Cd concentrations and moderate to high Zn/Cd ratios suggest mixing of seawater and minor magmatic fluids controlling the chemistry of sphalerite at both deposits during their formation.
Publisher: Copernicus GmbH
Date: 08-06-2022
DOI: 10.5194/GCHRON-4-353-2022
Abstract: Abstract. The ability to constrain the age of calcite formation is of great utility to the Earth science community, due to the ubiquity of calcite across a wide spectrum of geological systems. Here, we present the first in situ laser ablation inductively coupled tandem quadrupole mass spectrometry (LA-ICP-MS/MS) Lu–Hf ages for calcite, demonstrating geologically meaningful ages for iron oxide copper gold (IOCG) and skarn mineralisation, carbonatite intrusion, and low-grade metamorphism. The analysed s les range in age between ca. 0.9 and ca. 2 Ga with uncertainties between 1.7 % and 0.6 % obtained from calcite with Lu concentrations as low as ca. 0.5 ppm. The Lu–Hf system in calcite appears to be able to preserve primary precipitation ages over a significant amount of geological time, although further research is required to constrain the closure temperature. The in situ approach allows calcite to be rapidly dated while maintaining its petrogenetic context with mineralisation and other associated mineral processes. Therefore, LA-ICP-MS/MS Lu–Hf dating of calcite can be used to resolve the timing of complex mineral paragenetic sequences that are a feature of many ancient rock systems.
Publisher: Geological Society of London
Date: 17-12-2021
DOI: 10.1144/JGS2021-094
Abstract: The development of in situ laser ablation Lu–Hf geochronology of apatite, xenotime and garnet has opened avenues to quickly and directly date geological processes. We demonstrate the first use of c aign-style in situ Lu–Hf geochronology of garnet across the high- to ultrahigh-pressure Western Gneiss Region in Norway. Mafic eclogites from this region have been the focus of much work, and were clearly formed during continental subduction during the Caledonian Orogeny. However, abundant quartzofeldspathic and pelitic lithologies record a more complex history, with some preserving polymetamorphic age data, and most containing no indication of high-pressure mineral assemblages formed during subduction. Twenty metapelitic and felsic s les spanning 160 lateral kilometres across the Western Gneiss Region have been analysed using garnet Lu–Hf geochronology. The results reveal Caledonian ages for the majority of the garnets, suggesting that some quartzofeldspathic and metapelitic lithologies were reactive and grew garnet during high- to ultrahigh-pressure metamorphism. However, two ultrahigh-pressure eclogite locations, Verpeneset and Fjørtoft, preserve both Caledonian and Neoproterozoic-aged garnets. Despite significant uncertainties on some of the Lu–Hf geochronological ages, laser ablation Lu–Hf efficiently identifies the polymetamorphic history of parts of the Western Gneiss Region, illustrating the effectiveness of this novel analytical method for rapid mapping of metamorphic ages. Supplementary material: All laser ablation Lu–Hf geochronological data for the garnets analysed in this study are available at 0.6084/m9.figshare.c.5715453 Thematic collection: This article is part of the Caledonian Wilson cycle collection available at: c/caledonian-wilson-cycle
Publisher: MDPI AG
Date: 29-03-2022
DOI: 10.3390/GEOSCIENCES12040154
Abstract: Continental rifts have a significant role in supercontinent breakup and the development of sedimentary basins. The Australian Adelaide Superbasin is one of the largest and best-preserved rift systems that initiated during the breakup of Rodinia, yet substantial challenges still hinder our understanding of its early evolution and place within the Rodinian supercontinent. In the past decade, our understanding of rift and passive margin development, mantle plumes and their role in tectonics, geodynamics of supercontinent breakup, and sequence stratigraphy in tectonic settings has advanced significantly. However, literature on the early evolution of the Adelaide Superbasin has not been updated to reflect these advancements. Using new detrital zircon age data for provenance, combined with existing literature, we examine the earliest tectonic evolution of the Adelaide Superbasin in the context of our modern understanding of rift system development. A new maximum depositional age of 893 ± 9 Ma from the lowermost stratigraphic unit provides a revised limit on the initiation of sedimentation and rifting within the basin. Our model suggests that the basin evolved through an initial pulse of extension exploiting pre-existing crustal weakness to form half-grabens. Tectonic quiescence and stable subsidence followed, with deposition of a sourceward-shifting facies tract. Emplacement and extrusion of the Willouran Large Igneous Province occurred at c. 830 Ma, initiating a new phase of rifting. This rift renewal led to widespread extension and subsidence with the deposition of the Curdimurka Subgroup, which constitutes the main cyclic rift sequence in the Adelaide Superbasin. Our model suggests that the Adelaide Superbasin formed through rift propagation to an apparent triple junction, rather than apical extension outward from this point. In addition, we provide evidence suggesting a late Mesoproterozoic zircon source to the east of the basin, and show that the lowermost stratigraphy of the Centralian Superbasin, which is thought to be deposited coevally, had different primary detrital sources.
Publisher: Mineralogical Association of Canada
Date: 2019
Publisher: Cambridge University Press (CUP)
Date: 07-2023
DOI: 10.1017/S0016756823000390
Abstract: The glaciogenic nature of the Yudnamutana Subgroup was first recognized over a century ago, and its global significance was recognized shortly after, with the eventual postulation of a global Sturtian Glaciation and Snowball Earth theory. Much debate on the origin and timing of these rocks, locally and globally, has ensued in the years since. A significant corpus of research on the lithology, sedimentology, geochronology and formal lithostratigraphy of these sequences globally has attempted to resolve many of these debates. In the type area for the Sturtian Glaciation, South Australia’s Adelaide Superbasin, the lithostratigraphy and sedimentology are well understood however, formal stratigraphic nomenclature has remained complicated and contested. Absolute dates on the stratigraphy are also extremely sparse in this area. The result of these longstanding issues has been disagreement as to whether the sedimentary rocks of the Yudnamutana Subgroup are truly correlative throughout South Australia, and if they were deposited in the same time span recently defined for Sturtian glacial rocks globally, c. 717 Ma to c. 660 Ma. This study presents a large detrital zircon study, summarizes and compiles existing global geochronology for the Sturtian Glaciation and revises the formal lithostratigraphic framework of the Yudnamutana Subgroup. We show equivalence of the rocks that comprise the revised Sturt Formation, the main glaciogenic unit of the Yudnamutana Subgroup, and that it was deposited within the time span globally defined for the Sturtian Glaciation.
Publisher: Wiley
Date: 12-12-2019
DOI: 10.1111/TPJ.14599
Abstract: In saline soils, high levels of sodium (Na
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 05-2008
Publisher: Geological Society of America
Date: 14-04-2022
DOI: 10.1130/G49784.1
Abstract: Garnet is a fundamental expression of metamorphism and one of the most important minerals used to constrain the thermal conditions of the crust. We used innovative in situ laser-ablation ICP-MS/MS Lu-Hf geochronology to demonstrate that garnet in metapelitic rocks enclosing Cambrian eclogite in southern Australia formed during Laurentian Mesoproterozoic metamorphism. Garnet porphyroblasts in hibolite-facies metapelitic rocks yielded Lu-Hf ages between 1286 ± 58 Ma and 1241 ± 16 Ma, revealing a record of older metamorphism that was partially obscured by metamorphic overprinting during ca. 510 Ma Cambrian subduction along the East Gondwana margin. Existing detrital zircon age data indicate the protoliths to the southern Australian metapelitic rocks were sourced from western Laurentia. We propose that the metapelitic rocks of southern Australia represent a fragment of western Laurentian crust, which was separated from Laurentia in the Neoproterozoic and incorporated into the East Gondwana subduction system during the Cambrian. The ability to obtain Lu-Hf isotopic data from garnet at acquisition rates comparable to those for U-Pb analysis of detrital zircon means, for the first time, the metamorphic parentage of rocks as expressed by garnet can be efficiently accessed to assist paleogeographic reconstructions.
Publisher: Mineralogical Society of America
Date: 03-2019
DOI: 10.2138/AM-2019-6674
Publisher: MDPI AG
Date: 23-10-2017
DOI: 10.3390/MIN7100202
Publisher: Society of Economic Geologists
Date: 07-03-2013
Publisher: Society of Economic Geologists
Date: 12-2009
Publisher: Wiley
Date: 07-2014
DOI: 10.1002/GJ.2594
Publisher: Wiley
Date: 07-02-2020
DOI: 10.1002/PPP3.10090
Abstract: Cereal crops such as wheat and barley provide key nutritional elements to the human diet. However, the distribution of nutrients within the cereal grain itself is critically important, as nutrients can be lost during the grain milling process. Mycorrhizal fungi can take up nutrients from the soil and deliver them to plants, and consequently, grain nutrient content can be modified by inoculation of the soil with mycorrhizal fungi. Here we show at the microscopic level how mycorrhizal fungi modify the concentration and distribution of nutrients within wheat and barley grain, and consider the impact of this for human nutrition. Summary The concentration and distribution of nutrients in cereal grains are critically important for human nutrition. Mycorrhizal fungi affect the yield and nutrition of cereal crops, but there has been little focus on the effects on the grain, particularly at the microscopic level. Although arbuscular mycorrhizal fungi (AMF) can modify grain nutrient concentrations relative to mock‐inoculated plants, it is not known whether this contributes to modifications to the distribution of nutrients within the grain. Barley and bread wheat plants were grown to maturity with or without AMF ( Rhizophagus irregularis ) inoculation in soil amended with 20 mg added zinc kg −1 . The resulting grain from matured plants was dried, fixed and sectioned to the root primordia level, then subjected to laser ablation ICP‐MS to analyse the distribution and concentration of 12 elements. Elemental concentration and localisation in the grain s les was highly influenced by plant species, and for some elements, AMF inoculation. Heavy metals (zinc, iron, manganese, copper, cobalt and nickel) were the most highly influenced by AMF inoculation, particularly in wheat macronutrients including phosphorus, magnesium, potassium and sulphur were also affected by AMF, particularly in barley. Elemental concentrations, particularly of macronutrients, tended to be greater in mycorrhizal barley grain than non‐mycorrhizal, but the reverse was observed in wheat grain. Mycorrhizal plants of both species had reduced accumulation of manganese, nickel and cobalt in the grain.
Publisher: Elsevier BV
Date: 11-2011
Publisher: Elsevier BV
Date: 07-2023
Publisher: Elsevier BV
Date: 09-2015
Publisher: Springer Science and Business Media LLC
Date: 09-2003
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier BV
Date: 09-2023
Publisher: Geological Society of America
Date: 2022
DOI: 10.1130/G49187.1
Abstract: Authigenic components in marine sediments are important archives for past environment reconstructions. However, defining reliable age constraints and assessing the effects of post-depositional overprints in Precambrian sequences are challenging. We demonstrate a new laser-based analytical approach that has the potential to rapidly and accurately evaluate the depositional and alteration histories of Proterozoic shales. Our study employs a novel application of in situ Rb-Sr dating coupled with simultaneous trace-element analysis using reaction-cell laser ablation–inductively coupled plasma–tandem mass spectrometry (LA-ICP-MS/MS). We present results from shales sourced from two wells in the Proterozoic McArthur Basin, northern Australia. These rocks have been widely used by previous studies as a key section for ancient biogeochemical and paleo-redox reconstructions. Shales from well UR5 yielded initial 87Sr/86Sr ratios, Rb-Sr ages, and rare earth element plus yttrium (REEY) patterns similar to those of a dolerite s led from the same core. We propose that the UR5 s les chronicle hydrothermal alteration instigated by the dolerite intrusion. In contrast, a correlative shale from well UR6 yielded an age consistent with the expected depositional age (1577 ±56 Ma) with REEY and initial 87Sr/86Sr ratios similar to ca. 1.5 Ga seawater. We suggest that this s le records the minimum depositional age and early marine diagenetic history for this unit. This new technique can date Proterozoic shales quickly, cheaply, and with minimum s le preparation. Importantly, ages are triaged to differentiate between those recording primary marine versus secondary processes. This novel approach provides a potentially powerful tool for dating and fingerprinting the vast array of ancient marine shales for further studies of Earth systems through deep time.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0JA00224K
Abstract: Improved 204 Pb common Pb correction by LA-ICP-MS/MS for apatite and titanite U-Pb dating.
Publisher: Society of Economic Geologists
Date: 05-2022
DOI: 10.5382/ECONGEO.4886
Abstract: Extrusive and intrusive felsic magmas occur throughout the evolution of silicic-dominated large igneous province magmatism that is temporally related to numerous economically significant iron oxide copper-gold (IOCG) deposits in southern Australia. We investigate zircon trace element signatures of the felsic magmas to assess whether zircon composition can be related to fertility of the volcanic and intrusive suites within IOCG-hosted mineral provinces. Consistent with zircon forming in oxidizing magmatic conditions, the rare earth element (REE) patterns of zircon sourced from both extrusive and intrusive magmatic rocks are characterized by light REE depletions and a range of positive Ce and negative Eu anomalies. The timing of the major phase of IOCG mineralization overlaps with the early part of the first phase of Lower Gawler Range Volcanics magmatism (1593.6–1590.4 Ma) and older intrusive magmatism of the Hiltaba Suite (1593.06–1590.50 Ma). Zircon in these mineralization-related intrusives and extrusives is distinguished from zircon in younger, mineralization-absent rocks by higher Eu/Eu*, Ce/Ce*, and Ti values and separate magma evolution paths with respect to Hf. These zircon characteristics correspond to lower degrees of fractionation and/or crustal assimilation, more oxidizing magmatic conditions, and higher magmatic temperatures, respectively, in magmas coeval with mineralization. In this respect, we consider higher oxidation state, lower degrees of fractionation, and higher magmatic temperatures to be features of fertile magmas in southern Australian IOCG terrains. Similar zircon REE characteristics are shared between magmas associated with southern Australian IOCG and iron oxide-apatite (IOA) rhyolites from the St. Francois Mountains, Missouri, namely high Ce/Ce* and high Dy/Yb, indicative of oxidized and dry magmas, respectively. The dry and more fractionated nature of the IOCG- and IOA-associated magmas contrasts with the hydrous and unfractionated nature of fertile porphyry Cu deposit magmas. As indicated by high Ce/Ce* ratios, the oxidized nature is considered a key element in magma fertility in IOCG-IOA terrains. In both IOCG and IOA terrains, the trace element compositions of zircon are able to broadly differentiate fertile from nonfertile magmatic rocks.
Publisher: Geological Society of London
Date: 03-03-2020
DOI: 10.1144/JGS2019-132
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 04-2020
Publisher: Wiley
Date: 27-12-2022
DOI: 10.1111/GGR.12467
Abstract: Reference materials ( RMs ) with well‐characterised composition are necessary for reliable quantification and quality control of isotopic analyses of geological s les. For in situ Rb‐Sr analysis of silicate minerals via laser ablation inductively coupled plasma tandem mass spectrometry ( LA‐ICP‐MS / MS ) with a collision/reaction cell, there is a general lack of mineral‐specific and matrix‐matched RMs , which limits wider application of this new laser‐based dating technique to certain minerals. In this work, pressed nano‐powder pellets ( NP ) of four RMs , GL‐O (glauconite), Mica‐Mg (phlogopite), Mica‐Fe (biotite) and FK‐N (K‐feldspar), were analysed and tested for in situ Rb‐Sr dating, complemented by isotope dilution ( ID ) MC‐ICP‐MS Rb‐Sr analyses of GL‐O and Mica‐Mg . In addition, we attempted to develop alternative flux‐free and fused ‘mineral glasses’ from the above RMs for in situ Rb‐Sr dating applications. Overall, the results of this study showed that among the above RMs only two NP ( Mica‐Mg‐NP and GL‐O‐NP ) were suitable and robust for in situ dating applications. These two nano‐powder reference materials, Mica‐Mg‐NP and GL‐O‐NP , were thus used as primary RMs to normalise and determine Rb‐Sr ages for three natural minerals: MDC phlogopite and GL‐O glauconite grains, and also Mica‐Fe‐NP (biotite). Our in situ analyses of the above RMs yielded Rb‐Sr ages that are in good agreement (within 8%) of published ages, which suggests that both Mica‐Mg‐NP and GL‐O‐NP are suitable RMs for in situ Rb‐Sr dating of phlogopite, glauconite and biotite. However, using secondary RMs is recommended to monitor the quality of the obtained ages.
Publisher: Oxford University Press (OUP)
Date: 12-04-2010
Abstract: Pecl, G. T., Doubleday, Z. A., Danyushevsky, L., Gilbert, S., and Moltschaniwskyj, N. A. 2010. Transgenerational marking of cephalopods with an enriched barium isotope: a promising tool for empirically estimating post-hatching movement and population connectivity. – ICES Journal of Marine Science, 67: 1372–1380. Quantifying the movement of very small and young in iduals, determining sources of recruitment, and identifying the contribution of populations from different regions and periods to fished stocks is a major ecological challenge. Transgenerational isotope labelling (TRAIL), a technique which enables offspring to be marked on a mass scale, is applied for the first time to cephalopods, facilitating field studies quantifying population connectivity. Four species were used: Sepioteuthis australis, Euprymna tasmanica, Octopus pallidus, and Octopus maorum. Gravid females were injected with the enriched stable isotope 137Ba in different body tissues at several different doses. Isotopic ratios 138Ba:137Ba were then quantified using laser ablation inductively coupled plasma-mass spectrometry on the hard structures (statoliths and stylets) of offspring produced by the injected females. Day-old hatchlings from both squid species had statoliths with isotopic ratios significantly different from natural ratios and control animals, but variability in the ratios in hatchlings produced by different females was independent of dose or injection location. No differences were observed in the statoliths and stylets removed from hatchlings and juveniles, respectively, from the two octopus species, although isotopic shifts were evident in the hard structures of the adults injected. The use of TRAIL is a technique that offers considerable potential to advance the understanding of post-hatching dispersal and population connectivity in cephalopod populations.
Publisher: Elsevier BV
Date: 05-2022
Publisher: Copernicus GmbH
Date: 06-09-2022
DOI: 10.5194/GCHRON-4-577-2022
Abstract: Abstract. Recent developments in tandem laser ablation mass spectrometer technology have demonstrated the capacity for separating parent and daughter isotopes of the same mass online. As a result, beta-decay chronometers can now be applied to the geological archive in situ as opposed to through traditional whole-rock digestions. One novel application of this technique is the in situ Rb–Sr dating of Proterozoic shales that are dominated by authigenic clays such as illite. This method can provide a depositional window for shales by differentiating signatures of early diagenetic processes versus late-stage secondary alteration. However, the hydrothermal sensitivity of the Rb–Sr isotopic system across geological timescales in shale-hosted clay minerals is not well understood. As such, we dated the Mesoproterozoic Velkerri Formation from the Altree 2 well in the Beetaloo Sub-basin (greater McArthur Basin), northern Australia, using this approach. We then constrained the thermal history of these units using common hydrocarbon maturity indicators and modelled effects of contact heating due to the intrusion of the Derim Derim Dolerite. In situ Rb–Sr dating of mature, oil-prone shales in the diagenetic zone from the Velkerri Formation yielded ages of 1448 ± 81, 1434 ± 19, and 1421 ± 139 Ma. These results agree with previous Re–Os dating of the unit and are interpreted as recording the timing of an early diagenetic event soon after deposition. Conversely, overmature, gas-prone shales in the anchizone sourced from deeper within the borehole were dated at 1322 ± 93 and 1336 ± 40 Ma. These ages are younger than the expected depositional window for the Velkerri Formation. Instead, they are consistent with the age of the Derim Derim Dolerite mafic intrusion intersected 800 m below the Velkerri Formation. Thermal modelling suggests that a single intrusion of 75 m thickness would have been capable of producing a significant hydrothermal perturbation radiating from the sill top. The intrusion width proposed by this model is consistent with similar Derim Derim Dolerite sill thicknesses found elsewhere in the McArthur Basin. The extent of the hydrothermal aureole induced by this intrusion coincides with the window in which kerogen from the Velkerri Formation becomes overmature. As a result, the mafic intrusion intersected here is interpreted to have caused kerogen in these shales to enter the gas window, induced fluids that mobilize trace elements, and reset the Rb–Sr chronometer. Consequently, we propose that the Rb–Sr chronometer in shales may be sensitive to temperatures of ca. 120 ∘C in hydrothermal reactions but can withstand temperatures of more than 190 ∘C in thermal systems not dominated by fluids. Importantly, this study demonstrates a framework for the combined use of in situ Rb–Sr dating and kerogen maturation indicators to help reveal the thermochronological history of Proterozoic sedimentary basins. As such, this approach can be a powerful tool for identifying the hydrocarbon potential of source rocks in similar geological settings.
Publisher: Elsevier BV
Date: 02-2022
Publisher: Wiley
Date: 18-02-2022
DOI: 10.1111/TER.12580
Abstract: Apatite is increasingly used in sedimentary provenance studies. However, detrital apatite U–Pb geochronology can be challenging due to the presence of non‐radiogenic Pb, its intermediate closure temperature (~350–550°C) and/or age‐resetting by metamorphic/metasomatic processes. The Lu–Hf system in apatite has a higher closure temperature (~675–750°C) and is, therefore, more robust to thermal resetting. Here we present the first detrital apatite Lu–Hf age spectra. We have developed a laser‐ablation Lu–Hf dating technique, using reaction‐cell mass spectrometry, that allows rapid cost‐effective analysis, required for detrital apatite studies. The method is best suited to Precambrian detritus, permitting greater radiogenic Hf ingrowth. Using s les from Siberia, we demonstrate: (1) excellent correlations between U–Pb and Lu–Hf dates for apatites from igneous protoliths and (2) that Lu–Hf dating can detect primary age information in metamorphic grains. Hence, when used in tandem with U–Pb zircon and apatite geochronology, Lu–Hf apatite dating provides a powerful new tool for provenance studies.
Publisher: Society of Economic Geologists
Date: 13-08-2013
Publisher: Wiley
Date: 03-08-2012
Publisher: Elsevier BV
Date: 11-2023
Publisher: Elsevier BV
Date: 07-2020
Publisher: Springer Science and Business Media LLC
Date: 17-03-2021
Publisher: Wiley
Date: 13-06-2023
DOI: 10.1111/GGR.12512
Abstract: A new reference material, STDGL3, for the calibration of in situ analyses of sulfide minerals by LA‐ICP‐MS has been developed and characterised. It represents a lithium‐borate‐based glass containing a mixture of Zn‐ and Fe‐sulfide concentrates doped with several chalcophile elements as well as Zr, Gd, Hf and Ta required for assessing common interferences on Ag, Au and Pt. STDGL3 has a wider range of elements and a better homogeneity compared with existing reference materials for LA‐ICP‐MS analysis of sulfides. Compositional variations for most elements are below 3% RSD, below 5% RSD for Ag, Au and Pt, and below 7% RSD for Se, when performing spot analyses with a 50 μm beam size. Its preparation recipe is reproducible allowing for multiple batches to be made. Use of STDGL3 significantly improves accuracy of sulfide mineral analysis by LA‐ICP‐MS when compared with use of other available reference materials. Performance of STDGL3 was evaluated using several different laser systems. No significant change was observed between 193 nm ArF excimer lasers with 5 and 20 ns pulse widths, but use of 213 and 248 nm lasers displays more systematic differences, especially when analysing galena. Correction coefficients are needed for some elements (Zn and Cd in particular) when analysing sulfide minerals using STDGL3 as a calibration reference material.
Publisher: Springer Science and Business Media LLC
Date: 05-09-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0JA00299B
Abstract: The effect of physical/chemical properties and Rb/Sr elemental fractionation on the accuracy of in situ Rb–Sr dating via LA-ICP-MS/MS.
Publisher: Elsevier BV
Date: 05-2018
Publisher: Springer Science and Business Media LLC
Date: 25-08-2012
Publisher: Springer Science and Business Media LLC
Date: 28-08-2022
DOI: 10.1007/S00126-021-01067-Y
Abstract: Laser ablation-inductively coupled plasma-mass spectrometry and electron-probe microanalysis were used to investigate the trace-element contents of sphalerite, chalcopyrite and pyrite from the Plaka Pb–Zn–Ag deposit. Using petrographic observations, the analytical results could be linked to the temporal evolution of the Plaka ore-forming system. Sphalerite chemistry reliably records the temperature and f S 2 evolution of the system, with estimated formation temperatures reproducing the microthermometric results from previous fluid-inclusion studies. Chalcopyrite chemistry also shows systematic variations over time, particularly for Cd, Co, Ge, In, Sn and Zn concentrations. Measurable pyrite was only found in association with early high-temperature mineralisation, and no clear trends could therefore be identified. We note, however, that As and Se contents in pyrite are consistent with formation temperatures estimated from co-existing sphalerite. Statistical analysis of the sphalerite data allowed us to identify the dominant geological controls on its trace-element content. The three investigated factors temperature, f S 2 , and s le location account for 80% of the observed variance in Mn, Fe, Co, Ga, Ge, In, Sb and Hg concentrations, and 60% of the observed variance in Cd and Sn concentrations. Only for Cu and Ag concentrations is the explained variance 50%. A similarly detailed analysis was not possible for chalcopyrite and pyrite. Nevertheless, comparison of the results for all three investigated minerals indicates that there are some systematic variations across the deposit which may be explained by local differences in fluid composition.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4JA00011K
Publisher: MDPI AG
Date: 10-01-2020
DOI: 10.3390/MIN10010061
Abstract: Pyrite is the most common sulphide in a wide range of ore deposits and well known to host numerous trace elements, with implications for recovery of valuable metals and for generation of clean concentrates. Trace element signatures of pyrite are also widely used to understand ore-forming processes. Pyrite is an important component of the Olympic Dam Cu–U–Au–Ag orebody, South Australia. Using a multivariate statistical approach applied to a large trace element dataset derived from analysis of random pyrite grains, trace element signatures in Olympic Dam pyrite are assessed. Pyrite is characterised by: (i) a Ag–Bi–Pb signature predicting inclusions of tellurides (as PC1) and (ii) highly variable Co–Ni ratios likely representing an oscillatory zonation pattern in pyrite (as PC2). Pyrite is a major host for As, Co and probably also Ni. These three elements do not correlate well at the grain-scale, indicating high variability in zonation patterns. Arsenic is not, however, a good predictor for invisible Au at Olympic Dam. Most pyrites contain only negligible Au, suggesting that invisible gold in pyrite is not commonplace within the deposit. A minority of pyrite grains analysed do, however, contain Au which correlates with Ag, Bi and Te. The results are interpreted to reflect not only primary patterns but also the effects of multi-stage overprinting, including cycles of partial replacement and recrystallisation. The latter may have caused element release from the pyrite lattice and entrapment as mineral inclusions, as widely observed for other ore and gangue minerals within the deposit. Results also show the critical impact on predictive interpretations made from statistical analysis of large datasets containing a large percentage of left-censored values (i.e., those falling below the minimum limits of detection). The treatment of such values in large datasets is critical as the number of these values impacts on the cluster results. Trimming of datasets to eliminate artefacts introduced by left-censored data should be performed with caution lest bias be unintentionally introduced. The practice may, however, reveal meaningful correlations that might be diluted using the complete dataset.
Publisher: Elsevier BV
Date: 05-2009
Start Date: 07-2022
End Date: 07-2025
Amount: $284,494.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2023
End Date: 06-2026
Amount: $405,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2022
End Date: 12-2022
Amount: $389,526.00
Funder: Australian Research Council
View Funded Activity