ORCID Profile
0000-0003-2310-0517
Current Organisation
University of Adelaide
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Publisher: Wiley
Date: 04-2010
Publisher: Elsevier BV
Date: 2013
Publisher: Informa UK Limited
Date: 05-02-2023
Publisher: Elsevier BV
Date: 09-2011
Publisher: Wiley
Date: 28-12-2013
DOI: 10.1111/JMG.12060
Publisher: American Geophysical Union (AGU)
Date: 13-05-2005
DOI: 10.1029/2004TC001709
Publisher: Elsevier BV
Date: 05-2021
Publisher: Springer Science and Business Media LLC
Date: 30-03-2016
Publisher: Geological Society of America
Date: 11-2014
DOI: 10.1130/G36155.1
Publisher: Springer Science and Business Media LLC
Date: 11-2003
Publisher: Springer Science and Business Media LLC
Date: 21-07-2015
Publisher: Springer Science and Business Media LLC
Date: 02-05-2019
Publisher: Springer Science and Business Media LLC
Date: 05-2007
DOI: 10.1038/NATURE05759
Abstract: The chemical composition of basaltic magma erupted at the Earth's surface is the end product of a complex series of processes, beginning with partial melting and melt extraction from a mantle source and ending with fractional crystallization and crustal assimilation at lower pressures. It has been proposed that studying inclusions of melt trapped in early crystallizing phenocrysts such as Mg-rich olivine and chromite may help petrologists to see beyond the later-stage processes and back to the origin of the partial melts in the mantle. Melt inclusion suites often span a much greater compositional range than associated erupted lavas, and a significant minority of inclusions carry distinct compositions that have been claimed to s le melts from earlier stages of melt production, preserving separate contributions from mantle heterogeneities. This hypothesis is underpinned by the assumption that melt inclusions, once trapped, remain chemically isolated from the external magma for all elements except those that are compatible in the host minerals. Here we show that the fluxes of rare-earth elements through olivine and chromite by lattice diffusion are sufficiently rapid at magmatic temperatures to re-equilibrate completely the rare-earth-element patterns of trapped melt inclusions in times that are short compared to those estimated for the production and ascent of mantle-derived magma or for magma residence in the crust. Phenocryst-hosted melt inclusions with anomalous trace-element signatures must therefore form shortly before magma eruption and cooling. We conclude that the assumption of chemical isolation of incompatible elements in olivine- and chromite-hosted melt inclusions is not valid, and we call for re-evaluation of the popular interpretation that anomalous melt inclusions represent preserved s les of unmodified mantle melts.
Publisher: Springer Science and Business Media LLC
Date: 19-11-2016
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 09-2021
Publisher: Geological Society of America
Date: 08-08-2018
DOI: 10.1130/G45147.1
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 06-2017
Publisher: Society of Economic Geologists
Date: 07-02-2017
Publisher: Elsevier BV
Date: 07-2011
Publisher: Springer Science and Business Media LLC
Date: 15-10-2016
Publisher: eLife Sciences Publications, Ltd
Date: 09-05-2017
DOI: 10.7554/ELIFE.24231
Abstract: New ages for flowstone, sediments and fossil bones from the Dinaledi Chamber are presented. We combined optically stimulated luminescence dating of sediments with U-Th and palaeomagnetic analyses of flowstones to establish that all sediments containing Homo naledi fossils can be allocated to a single stratigraphic entity (sub-unit 3b), interpreted to be deposited between 236 ka and 414 ka. This result has been confirmed independently by dating three H. naledi teeth with combined U-series and electron spin resonance (US-ESR) dating. Two dating scenarios for the fossils were tested by varying the assumed levels of 222Rn loss in the encasing sediments: a maximum age scenario provides an average age for the two least altered fossil teeth of 253 +82/–70 ka, whilst a minimum age scenario yields an average age of 200 +70/–61 ka. We consider the maximum age scenario to more closely reflect conditions in the cave, and therefore, the true age of the fossils. By combining the US-ESR maximum age estimate obtained from the teeth, with the U-Th age for the oldest flowstone overlying Homo naledi fossils, we have constrained the depositional age of Homo naledi to a period between 236 ka and 335 ka. These age results demonstrate that a morphologically primitive hominin, Homo naledi, survived into the later parts of the Pleistocene in Africa, and indicate a much younger age for the Homo naledi fossils than have previously been hypothesized based on their morphology.
Publisher: Society of Economic Geologists
Date: 2020
DOI: 10.5382/ECONGEO.4698
Abstract: At the Antamina deposit, Peru, accurate classification of exoskarns and endoskarns can be problematic when textures are mottled. In this study, we use whole-rock geochemical compositions (62 elements) of 221 s les to differentiate texturally similar endoskarns and exoskarns by comparing their compositions to least altered precursors (wall rocks and intrusive rocks). We present a simple method for discriminating these skarn types using immobile element bivariate plots. The most effective discriminators partition endoskarn and exoskarn into distinct domains defined by the composition of each precursor these include Al2O3 versus heavy rare earth elements and some high field strength elements. Using these geochemical parameters, undifferentiated skarn s les can be more reliably classified as endoskarn or exoskarn. The effectiveness of these element pairs is attributed to their significantly different initial concentrations in wall rocks versus igneous precursors and their immobility during skarn formation. While immobile elements can differentiate the skarns, mobile element gains and losses (quantified using isocon analysis) provide insight on the bulk mineralogical and mass changes that take place during skarn formation.
Publisher: Elsevier BV
Date: 05-2004
Publisher: Springer Science and Business Media LLC
Date: 31-07-2007
Publisher: Springer Science and Business Media LLC
Date: 03-2020
Publisher: Springer Science and Business Media LLC
Date: 05-02-2021
DOI: 10.1186/S00015-020-00380-4
Abstract: Exhumation of basement rocks on the seafloor is a worldwide feature along passive continental margins and (ultra-) slow-spreading environments, documented by dredging, drilling or direct observations by ing expeditions. Complementary observations from exhumed ophiolites in the Alps allow for a better understanding of the underlying processes. The Aiguilles Rouges ophiolitic units (Val d’Hérens, Switzerland) are composed of kilometre-scale remnants of laterally segmented oceanic lithosphere only weakly affected by Alpine metamorphism (greenschist facies, Raman thermometry on graphite: 370–380 °C) and deformation. Geometries and basement-cover sequences comparable to the ones recognized in actual (ultra-) slow-spreading environments were observed, involving exhumed serpentinized and carbonatized peridotites, gabbros, pillow basalts and tectono-sedimentary cover rocks. One remarkable feature is the presence of a kilometric gabbroic complex displaying preserved magmatic minerals, textures and crosscutting relationships between the host gabbro and intruding diabase, hornblende-bearing dikelets or plagiogranite. The bulk major and trace element chemistry of mafic rocks is typical of N-MORB magmatism (Ce N /Yb N : 0.42–1.15). This is supported by in-situ isotopic signatures of magmatic zircons (εHf = + 13 ± 0.6) and apatites (εNd = + 8.5 ± 0.8), determined for gabbros and plagiogranites. In-situ U–Pb dating was performed on zircons by laser ablation-ICP-MS, providing ages of 154.9 ± 2.6 Ma and 155.5 ± 2.8 Ma, which are among the youngest for oceanic gabbros in the Alps. Our study suggests that the former Aiguilles Rouges domain was characterized by tectonism and magmatism resembling present-day (ultra-) slow-spreading seafloor. It also suggests that the Tethyan lithosphere is laterally segmented, with punctuated magmatism such as the Aiguilles Rouges gabbros and carbonated ultramafic seafloor covered by basalts and Jurassic tectono-sedimentary deposits.
Publisher: Mineralogical Society of America
Date: 2019
DOI: 10.2138/AM-2019-6466
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1JA00044F
Abstract: A small degree of laser defocusing can lead to significant changes in the ablation pit morphology and downhole fractionation of U–Pb isotopes.
Publisher: Geological Society of America
Date: 23-07-2021
DOI: 10.1130/G49328.1
Abstract: The tectonic setting of the Australian sector of the eastern Gondwanan margin during the Jurassic and Cretaceous is enigmatic. Whether this involved convergent tectonism and a long-lived continental magmatic arc or rift-related extension unrelated to subduction is debated. The paucity of Australian Jurassic–Cretaceous igneous outcrops makes resolving these competing models difficult. We used the detrital zircon record of the Jurassic–Cretaceous Great Australian Superbasin (GAS) as a proxy for igneous activity. We attribute the persistent magmatism recorded in GAS sedimentary fill throughout the Mesozoic to ca. 95 Ma to continuation of the established Paleozoic continental arc system. The detrital zircon record signals short (~10 m.y.) pulses of elevated Jurassic and Cretaceous magmatic activity and strongly positive εHf values, indicating juvenile crust or mantle-derived magmatism. Margin reconstruction indicates sustained continental growth at rates of at least ~55 km3 km–1 m.y.–1, mainly to the tract now represented by submerged northern Zealandia, due to the retreat of this arc system. We posit that arc retreat was a key factor in rapid crust generation and preservation, and that continental sedimentary systems globally may host cryptic records of juvenile crustal addition that must be considered in estimating crustal growth rates along convergent plate margins.
Publisher: Oxford University Press (OUP)
Date: 04-12-2007
Publisher: Geological Society of America
Date: 2005
DOI: 10.1130/G21912.1
Publisher: Elsevier BV
Date: 2021
Publisher: Springer Science and Business Media LLC
Date: 24-05-2012
Publisher: Elsevier BV
Date: 10-2019
Publisher: Society of Economic Geologists
Date: 28-12-2021
DOI: 10.5382/ECONGEO.4806
Abstract: The Early Permian Lizzie Creek Volcanic Group of the northern Bowen Basin, NE Queensland, Australia, has compositions that range from basalt through andesite to rhyolite with geochemical signatures (e.g., enrichment in Cs, Rb, Ba, U, Th, and Pb, depletion in Nb and Ta) that are typical of arc lavas. In the Mount Carlton district the Lizzie Creek Volcanic Group is host to high-sulfidation epithermal Cu-Au-Ag mineralization, whereas farther to the south near Collinsville (~50 km from Mount Carlton) these volcanic sequences are barren of magmatic-related mineralization. Here, we assess whether geochemical indicators of magma fertility (e.g., Sr/Y, La/Yb, V/Sc) can be applied to volcanic rocks through study of coeval volcanic sequences from these two locations. The two volcanic suites share similar petrographic and major element geochemical characteristics, and both have undergone appreciable hydrothermal alteration during, or after, emplacement. Nevertheless, the two suites have distinct differences in alteration-immobile trace element (V, Sc, Zr, Ti, REE, Y) concentrations. The unmineralized suite has relatively low V/Sc and La/Yb, particularly in the high SiO2 rocks, which is related to magma evolution dominated by fractionation of clinopyroxene, plagioclase, and magnetite. By contrast, the mineralized suite has relatively high V/Sc but includes high SiO2 rocks with depleted HREE and Y contents, and hence high La/Yb. These trends are interpreted to reflect magma evolution under high magmatic H2O conditions leading to enhanced hibole crystallization and suppressed plagioclase and magnetite crystallization. These rocks have somewhat elevated Sr/Y compared to the unmineralized suite, but as Sr is likely affected by hydrothermal mobility, Sr/Y is not considered to be a reliable indicator of magmatic conditions. Our data show that geochemical proxies such as V/Sc and La/Yb that are used to assess Cu-Au fertility of porphyry intrusions can also be applied to cogenetic volcanic sequences, provided elemental trends with fractionation can be assessed for a volcanic suite. These geochemical tools may aid regional-scale exploration for Cu-Au mineralization in convergent margin terranes, especially in areas that have undergone limited exhumation or where epithermal and porphyry mineralization may be buried beneath cogenetic volcanic successions.
Publisher: Elsevier BV
Date: 08-2012
Publisher: Elsevier BV
Date: 06-2006
Publisher: Wiley
Date: 06-2008
Publisher: Elsevier BV
Date: 10-2015
Publisher: Springer Science and Business Media LLC
Date: 17-08-2019
Publisher: Elsevier BV
Date: 04-2014
Publisher: Society of Economic Geologists
Date: 09-2018
Publisher: Elsevier BV
Date: 09-2013
Publisher: Springer Science and Business Media LLC
Date: 11-11-2009
Publisher: Elsevier BV
Date: 04-2014
Publisher: Informa UK Limited
Date: 03-2005
Publisher: Society of Economic Geologists
Date: 11-2021
DOI: 10.5382/ECONGEO.4840
Abstract: Precambrian iron oxide copper-gold (IOCG) deposits are generally encountered with multistage hydrothermal overprints and hence have complex isotopic records. Precise dating of ore-forming and overprinting events and assessment of time-resolved metal sources are fundamental for understanding ore genesis. Here, we quantify the evolution history by integrating in situ U-Pb dating of texturally constrained allanite and Sm-Nd isotope data of ores and major rare earth element (REE) minerals in the breccia-hosted Lanniping Fe-Cu deposit in Kangdian region, southwestern China. The economically mineralized breccia in Lanniping Fe-Cu deposit is characterized by pervasive and texturally destructive replacement of polymictic clasts, including host metasedimentary packages, the intruded dolerite, and pre-ore halokinetic breccia. Ore minerals in cements are mainly composed of magnetite, chalcopyrite, bornite, and variable amounts of REE-rich minerals (e.g., apatite and allanite/epidote). Two types of allanite were identified in ores. Type I prismatic allanite texturally intergrown with magnetite has a SHRIMP U-Pb age of 1728 ± 20 Ma (1σ), which matches a zircon U-Pb age of 1713 ± 14 Ma (2σ) for the dolerite clasts and provides the direct age constraint on the Fe-Cu mineralization event. Type II anhedral allanite shows complex zoning and is spatially associated with, but texturally later than, magnetite, apatite, and chalcopyrite. This type of allanite yields significantly younger SHRIMP dates of 1015 ± 33 (1σ) and 800 ± 16 Ma (1σ) for cores and rims, respectively, which correspond to discrete regional magmatic events and hence record hydrothermal overprint/remobilization events of ore minerals in the deposit. Integrated Sm-Nd isotope compositions of type I allanite, apatite, and whole ores generally align along the reference Sm-Nd isochron of 1728 Ma, further confirming the primary ore formation at ~1.7 Ga. Corresponding εNd(1728 Ma) values ranging from –2.8 to 0.3 are significantly higher than those of the host metasedimentary rocks (–9.5 to –6.2) but comparable to those of contemporaneous igneous intrusions (–0.3 to 5.3) in the region, demonstrating that REE components of the primary ores were dominantly sourced from rocks of mantle-derived affinity. Both cores and rims of the younger type II allanite grains have Nd isotope compositions consistent with the unique time-evolved line of the ~1.7 Ga ores, implying that REEs incorporated into type II allanite were ultimately sourced from the primary ores in this deposit. The combined texture, chemical, U-Pb, and Sm-Nd isotope data thus demonstrate that REE remobilization was localized during post-ore hydrothermal overprint with negligible external inputs of REEs to the primary ores in the Lanniping deposit. In this contribution, we not only date primary ore formation but also recognize several younger allanite generations that record internal metal redistributions in response to post-ore tectonothermal events. Our study highlights the potential of ore-associated REE minerals such as allanite for resolving the age of multiple stages of hydrothermal events in complex ore deposits by ion probe, provided that careful examination of textural and paragenetic relationship of ores is conducted. Our finding of these younger allanite generations also exemplifies the significance of evaluation on time-resolved metal input for better characterizing the evolution history of the IOCG deposits.
Publisher: Informa UK Limited
Date: 05-2016
DOI: 10.5408/15-095.1
Publisher: Elsevier BV
Date: 12-2019
Publisher: Springer Science and Business Media LLC
Date: 05-07-2015
Publisher: Oxford University Press (OUP)
Date: 16-12-2011
Publisher: Elsevier BV
Date: 03-2019
Publisher: Springer Science and Business Media LLC
Date: 06-10-2015
Publisher: American Geophysical Union (AGU)
Date: 30-07-2020
DOI: 10.1029/2019JB019075
Abstract: Establishing spatial, temporal, and geochemical relationships between magmatism and the broader tectonics of accretionary orogens is important for understanding continental crustal growth processes. Here we reconstruct the Paleozoic and Mesozoic evolution of the active continental margin of Zealandia (eastern Gondwana), using a combination of detrital zircon geochronology, trace element geochemistry and Hf isotope data. We find that zircon grains dated 360–160 Ma from New Zealand are characterized by εHf i (+15 to +2) and trace element compositions typical of predominantly juvenile magmatic sources. In contrast, the εHf i (+15 to −5) and trace element compositions of detrital zircon grains dated 245–140 Ma from New Caledonia reflect a mix of juvenile and evolved crustal sources. Secular trends in trace element and Hf isotope compositions of zircon grains suggest that magmatism and continental crustal growth in Zealandia during the Devonian‐Cretaceous were controlled by switches from trench advance to trench retreat. Orogenesis and crustal growth were controlled by a long‐lived westward dipping subduction system, which during the Permian‐Triassic, was intermittently affected by distinct phases of arc accretion (e.g., of the Brook Street intraoceanic arc) and orogenesis (e.g., driven by trench advance). These phases of orogenesis coincided with the Gondwanide Orogen (265–230 Ma), which might have been controlled by a plate‐scale reorganization event following the final assembly of Pangea supercontinent.
Publisher: Informa UK Limited
Date: 09-05-2022
Publisher: Elsevier BV
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 10-11-2021
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 12-2006
Publisher: Elsevier BV
Date: 04-2007
Publisher: Elsevier BV
Date: 05-2016
Publisher: Mineralogical Association of Canada
Date: 09-2018
Publisher: Elsevier BV
Date: 06-2017
Publisher: Elsevier BV
Date: 08-2018
Publisher: ACM
Date: 26-11-2013
Publisher: Elsevier BV
Date: 04-2020
Publisher: Springer Science and Business Media LLC
Date: 15-10-2004
Publisher: Oxford University Press (OUP)
Date: 06-2011
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 02-2022
Publisher: Oxford University Press (OUP)
Date: 23-12-2009
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 06-2013
Publisher: American Association for the Advancement of Science (AAAS)
Date: 08-07-2022
Abstract: We describe the first occurrence of diamond-facies ultrahigh pressure metamorphism along the Gondwana-Pacific margin of the Terra Australis Orogen. Metamorphic garnet grains from Ordovician metasediments along the Clarke River Fault in northeastern Queensland contain inclusions of diamond and quartz after coesite, as well as exsolution lamellae of rutile, apatite, hibole, and silica. These features constrain minimum pressure-temperature conditions to .5 gigapascals and ~860°C, although peak pressure conditions may have exceeded 5 gigapascals. On the basis of these data, we interpret the Clarke River Fault to represent a Paleozoic suture zone and at least parts of the Terra Australis Orogen to have formed through classic Wilson cycle processes. The growth of the Terra Australis Orogen during the Paleozoic is largely attributed to accretionary style tectonics. These previously unknown findings indicate that the Terra Australis Orogen was not just a simple accretionary style orogen but rather a complex system with multiple tectonic styles operating in tandem including collisional tectonics.
Publisher: Elsevier BV
Date: 05-2015
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 08-2013
No related grants have been discovered for Carl Spandler.