Earth and Environmental Sciences publications
Permanent URI for this collection
Browse
Recent Submissions
Item Metadata only A late nineteenth century collection of fossils from the Naracoorte Caves highlights the role of the South Australian Museum in the history of the site(Australian Speleological Federation Inc., 2023) Reed, E.; Treloar, J.-B.; Binnie, M.-A.; Thurmer, J.The Naracoorte Caves World Heritage site is renowned for its well-preserved deposits of fossil vertebrates spanning the last 500,000 years. Palaeontological research at the Caves began in earnest in 1969 following the discovery of the Fossil Chamber in Victoria Cave. Prior to that, records of fossil discoveries were largely restricted to incidental finds of material during caving activities or cave tourism developments in the Caves Reserve and the broader Naracoorte cave complex. The Reverend Julian Tenison-Woods first reported vertebrate fossils from Naracoorte Caves in 1858. However, there is no record of museum accession for this material and its current whereabouts is unknown. Discovery of megafauna fossil material was widely reported in 1908 and later, but there is very limited information regarding fossil collections made at Naracoorte during the middle to late nineteenth century. Here we report on fossil material collected from Naracoorte Caves and curated at the South Australian Museum by Amandus Zietz in 1888. The collection includes a range of small bones that are labelled and mounted, suggesting they were once used for public outreach or display. These fossils may represent the earliest museum collection currently known from Naracoorte Caves and highlight the South Australian Museum’s long association with the caves and the early history of palaeontological investigation at this globally significant locality.Item Open Access The inhibited response of accessory minerals during high-temperature reworking(Wiley, 2024) March, S.; Hand, M.; Morrissey, L.; Kelsey, D.U–Pb zircon and monazite geochronology are considered to be among the most efficient and reliable methods for constraining the timing of hightemperature (HT) metamorphic events. However, the reliability of these chronometers is coupled to their ability to participate in reactions. A case study examining the responsiveness of zircon and monazite has been conducted using granulite facies metapelitic and metamafic lithologies in the Warumpi Province, central Australia. In some instances, metapelitic granulites from this locality are polymetamorphic, with an early M1 assemblage containing orthopyroxene, cordierite, biotite, quartz, ilmenite and magnetite, and an M2 assemblage represented by garnet, sillimanite, orthopyroxene, cordierite, biotite, sapphirine, ilmenite and magnetite. M2 metamorphism is linked to HT peak conditions of 8–10 kbar and 850–915 C. Detrital and metamorphic zircon and monazite from these rocks dominantly record U–Pb dates of 1670–1610 Ma and have trace element compositions suggesting they grew prior to peak M2 garnet in the rock. Lu–Hf geochronology from M2 garnet gives ages of c. 1150 Ma. Zircon and monazite are therefore suggested to have remained largely inert during HT metamorphism. We attribute the relatively minor response of zircon and monazite during high-temperature Mesoproterozoic metamorphism to the localized development of refractory bulk compositions at c. 1630 Ma during M1 metamorphism. This created refractory Mg–Al-rich bulk compositions that were unable to undergo significant partial melting, despite experiencing subsequent temperatures of 900 C at c. 1150 Ma. In contrast, metapelitic and metamafic rocks in the area that did not develop refractory bulk compositions during M1 metamorphism were able to partially melt and record c. 1150 Ma accessory mineral U–Pb ages. These results contribute to a small, but growing number of case studies investigating the systematics of the U–Pb system in zircon and monazite in polymetamorphic HT terranes and their apparent resistance to isotopic resetting. Where disequilibrium is apparent, garnet Lu–Hf geochronology can form an important tool to interrogate the significance of accessory U–Pb ages. In the Warumpi Province in central Australia, c. 1640 Ma zircon U–Pb ages had previously been interpreted to reflect the formation of HT garnet-bearing granulites during a collisional event. Instead, the garnet-bearing assemblages formed at c. 1150 Ma during the Mesoproterozoic, calling into question the existence of a late Palaeoproterozoic collisional system in central Australia.Item Metadata only Provenance of rifted continental crust at the nexus of East Gondwana breakup(Elsevier BV, 2020) Halpin, J.A.; Daczko, N.R.; Direen, N.G.; Mulder, J.A.; Murphy, R.C.; Ishihara, T.The Bruce Rise, a prominent bathymetric feature offshore the Bunger Hills (East Antarctica), has basement of unknown crustal affinity and age. In East Gondwana, the Bruce Rise is reconstructed near the Naturaliste Plateau (offshore SW Australia) and microcontinents now submerged in the eastern Indian Ocean. New zircon U-Pb-Hf data from two c. 1150 Ma granite samples dredged from the eastern escarpment of the Bruce Rise demonstrate that these rocks are dominated by xenocrystic cargo. Mesoproterozoic xenocrystic cores show textural evidence of melt-mediated coupled dissolution-precipitation to form rim domains with apparent ages that skew towards c. 1150 Ma. The zircon U-Pb-Hf signatures from the xenocrysts in the Bruce Rise granites, and from c. 1230 to 1180 Ma felsic-intermediate granites and orthogneisses from the conjugate Naturaliste Plateau basement, suggest late Mesoproterozoic magmatism occurred at a transition in the regional tectonic architecture between a reworked Archean cratonic margin and Proterozoic juvenile crust. On the basis of plate reconstructions, exhumation and thinning of the basement to the Bruce Rise/Naturaliste Plateau occurred predominantly during rifting of India (prior to c. 120 Ma). Minor further thinning likely occurred leading up to the onset of seafloor spreading between Australia/Naturaliste Plateau and Antarctica/Bruce Rise (from c. 90 to 84 Ma).Item Open Access Radiogenic heat production drives Cambrian–Ordovician metamorphism of the Curnamona Province, south-Central Australia: Insights from petrochronology and thermal modelling(Elsevier BV, 2023) De Vries Van Leeuwen, A.T.; Raimondo, T.; Morrissey, L.J.; Hand, M.; Hasterok, D.; Clark, C.; Anczkiewicz, R.Multi-mineral petrochronology can effectively track changes in the thermochemical environment experienced by rocks during metamorphism. We demonstrate this concept using garnet–chlorite schists from the Walter-Outalpa Shear Zone of the southern Curnamona Province, South Australia, which reveal a cryptic and protracted (c. 39 Myr) record of high thermal gradient metamorphism. Petrochronological data including in situ monazite U–Pb and garnet Lu–Hf and Sm–Nd dating suggest elevated geotherms were persistent between at least c. 519–480 Ma, throughout the duration of garnet growth. Additional in situ xenotime U–Pb dating implies that partial garnet breakdown occurred between c. 480–440 Ma, likely induced by fluid-rock interaction or exhumation. Although metamorphism temporally overlaps with the timing of the regional Delamerian Orogeny (c. 520–480 Ma), the thermal mechanism to sustain elevated temperatures has remained enigmatic. One-dimensional thermal models are used to appraise the role of radiogenic heat production in driving the observed high thermal gradient metamorphism. The models reveal that with only modest crustal thickening during orogenesis, the endogenous radiogenic heat production hosted within the basement rocks could plausibly provide the thermal impetus for metamorphism.Item Metadata only Rodinian devil in disguise: Correlation of 1.25-1.10 Ga strata between Tasmania and Grand Canyon(Geological Society of America, 2018) Mulder, J.A.; Karlstrom, K.E.; Halpin, J.A.; Merdith, A.S.; Spencer, C.J.; Berry, R.F.; McDonald, B.Locating the continuation of the ca. 1.30–1.00 Ga Grenville orogen on continents formerly adjacent to Laurentia is central to resolving the paleogeography of the supercontinent Rodinia. Here we emphasize a correlation of late Mesoproterozoic foreland basins that, prior to truncation by Neoproterozoic rift margins, may have extended west of Laurentia within Rodinia. We propose correlation of the Unkar Group (Grand Canyon, Arizona, USA) with the upper Rocky Cape Group (Tasmania, southeast Australia) based on their similar stratigraphy, 1.25–1.10 Ga depositional age, and detrital zircon U-Pb age distribution and Hf isotope composition. This correlation places Tasmania adjacent to southwest Laurentia in the late Mesoproterozoic, which supports a new paleogeographic model for Rodinia. In this model, Tasmania and crustal fragments of Laurentia comprising the South Tasman Rise and the Coats Land block form key links between the Grenville orogen in southwest Laurentia and the Maud orogen (East Antarctica). A 1.14–1.07 Ga connection between the combined Grenville-Maud orogen and the Musgrave orogen of central Australia is compatible with paleomagnetic data but requires ∼4000 km of relative motion between Australia-Antarctica and Laurentia prior to the final assembly of Rodinia at ca. 0.90 Ga. We hypothesize that the final assembly of Rodinia was achieved by dextral motion between the crust of Australian and Laurentian affinity along a plate boundary concealed beneath ice cover in East Antarctica.Item Open Access The effects of climate change on the ecology of fishes(Public Library of Science (PLoS), 2023) Nagelkerken, I.; Allan, B.J.M.; Booth, D.J.; Donelson, J.M.; Edgar, G.J.; Ravasi, T.; Rummer, J.L.; Vergés, A.; Mellin, C.; Yu, W.Ocean warming and acidification are set to reshuffle life on Earth and alter ecological processes that underpin the biodiversity, health, productivity, and resilience of ecosystems. Fishes contribute significantly to marine, estuarine, and freshwater species diversity and the functioning of marine ecosystems, and are not immune to climate change impacts. Whilst considerable effort has been placed on studying the effects of climate change on fishes, much emphasis has been placed on their (eco)physiology and at the organismal level. Fishes are affected by climate change through impacts at various levels of biological organisation and through a large variety of traits, making it difficult to make generalisations regarding fish responses to climate change. Here, we briefly review the current state of knowledge of climate change effects on fishes across a wide range of subfields of fish ecology and evaluate these effects at various scales of biological organisation (from genes to ecosystems). We argue that a more holistic synthesis of the various interconnected subfields of fish ecology and integration of responses at different levels of biological organisation are needed for a better understanding of how fishes and their populations and communities might respond or adapt to the multi-stressor effects of climate change. We postulate that studies using natural analogues of climate change, meta-analyses, advanced integrative modelling approaches, and lessons learned from past extreme climate events could help reveal some general patterns of climate change impacts on fishes that are valuable for management and conservation approaches. Whilst these might not reveal many of the underlying mechanisms responsible for observed biodiversity and community change, their insights are useful to help create better climate adaptation strategies for their preservation in a rapidly changing ocean.Item Open Access Sediment microfabric records mass sedimentation of colonial cyanobacteria and extensive syndepositional metazoan reworking in Pliocene sapropels(Wiley, 2018) Löhr, S.C.; Kennedy, M.J.; George, S.C.; Williamson, R.J.; Xu, H.The sapropel record of the eastern Mediterranean provides unique insight into the primary climatic, oceanographic, and biological drivers of organic carbon enrichment in marine sediments. The dominant source of organic matter, timing of oxygen depletion at the sea floor, and extent of metazoan reworking of these deposits remain unclear. These questions are addressed by combining microbeam imaging with bulk and molecular geochemical characterization of several Pliocene sapropels, revealing four microfacies which record distinct palaeoceanographic conditions, phytoplankton assemblages, and degrees of postdepositional reworking. The most organic‐rich, carbonate‐lean sapropel intervals consist of alternating 10–60‐μm‐thick organic and detrital mineral laminae. Petrographical features consistent with a pelagic origin, δ15N 50 μm organomineral aggregates, interpreted as marine snow, whereas carbonate microfossil‐rich intervals record periods of nitrogen fixation and moderately increased primary production by a diverse assemblage of calcareous, organic‐walled, and siliceous plankton. The results presented here further show that burrowing by microscopic meiofauna impacted most sapropels, extending into seemingly laminated intervals below obvious disruption from burrowing macrofauna, indicating that metazoans influence organic carbon burial in oxygen‐depleted settings even where physical displacement of sediment is not visible.Item Metadata only Can native predators be used as a stepping stone to reduce prey naivety to novel predators?(Oxford University Press, 2023) van der Weyde, L.K.; Blumstein, D.T.; Letnic, M.; Tuft, K.; Ryan-Schofield, N.; Moseby, K.E.; Candolin, U.Predator naivety negatively affects reintroduction success, and this threat is exacerbated when prey encounters predators with which they have had no evolutionary experience. While methods have been developed to inculcate fear into such predator-naïve individuals, none have been uniformly successful. Exposing ontogenetically- and evolutionary-naïve individuals first to native predators may be an effective stepping stone to improved responses to evolutionarily novel predators. We focused on greater bilbies (Macrotis lagotis) and capitalized on a multi-year mammalian recovery experiment whereby western quolls (Dasyurus geoffroii) were reintroduced into parts of a large fenced reserve that contained a population of naïve bilbies. We quantified a suite of anti-predator behaviors and measures of general wariness across quoll-exposed and quoll-naive bilby populations. We then translocated both quoll-exposed and quoll-naïve individuals into a large enclosure that contained feral cats (Felis catus) and monitored several behaviors. We found that bilbies can respond appropriately to quolls but found only limited support that experience with quolls better-prepared bilbies to respond to cats. Both populations of bilbies rapidly modified their behavior in a similar manner after their reintroduction to a novel environment. These results may have emerged due to insufficient prior exposure to quolls, inappropriate behavioral tests, or insufficient predation risk during cat exposure. Alternatively, quolls and cats are only distantly related and may not share sufficient similarities in their predatory cues or behavior to support such a learning transfer. Testing this stepping stone hypothesis with more closely related predator species and under higher predation risk would be informative.Item Open Access Terraced iron formations: Biogeochemical processes contributing to microbial biomineralization and microfossil preservation(MDPI AG, 2018) Shuster, J.; Rea, M.A.; Etschmann, B.; Brugger, J.; Reith, F.Terraced iron formations (TIFs) are laminated structures that cover square meter-size areas on the surface of weathered bench faces and tailings piles at the Mount Morgan mine, which is a non-operational open pit mine located in Queensland, Australia. Sampled TIFs were analyzed using molecular and microanalytical techniques to assess the bacterial communities that likely contributed to the development of these structures. The bacterial community from the TIFs was more diverse compared to the tailings on which the TIFs had formed. The detection of both chemolithotrophic iron-oxidizing bacteria, i.e., Acidithiobacillus ferrooxidans and Mariprofundus ferrooxydans, and iron-reducing bacteria, i.e., Acidobacterium capsulatum, suggests that iron oxidation/reduction are continuous processes occurring within the TIFs. Acidophilic, iron-oxidizing bacteria were enriched from the TIFs. High-resolution electron microscopy was used to characterize iron biomineralization, i.e., the association of cells with iron oxyhydroxide mineral precipitates, which served as an analog for identifying the structural microfossils of individual cells as well as biofilms within iron oxyhydroxide laminations—i.e., alternating layers containing schwertmannite (Fe16O16(OH)12(SO4)2) and goethite (FeO(OH)). Kinetic modeling estimated that it would take between 0.25–2.28 years to form approximately one gram of schwertmannite as a lamination over a one-m2 surface, thereby contributing to TIF development. This length of time could correspond with seasonable rainfall or greater than average annual rainfall. In either case, the presence of water is critical for sustaining microbial activity, and subsequently iron oxyhydroxide mineral precipitation. The TIFs from the Mount Morgan mine also contain laminations of gypsum (CaSO·2H2O) alternating with iron oxyhydroxide laminations. These gypsum laminations likely represented drier periods of the year, in which millimeter-size gypsum crystals presumably precipitated as water gradually evaporated. Interestingly, gypsum acted as a substrate for the attachment of cells and the growth of biofilms that eventually became mineralized within schwertmannite and goethite. The dissolution and reprecipitation of gypsum suggest that microenvironments with circumneutral pH conditions could exist within TIFs, thereby supporting iron oxidation under circumneutral pH conditions. In conclusion, this study highlights the relationship between microbes for the development of TIFs and also provides interpretations of biogeochemical processes contributing to the preservation of bacterial cells and entire biofilms under acidic conditions.Item Metadata only The Acheulean Technocomplex of the Iberian Atlantic Margin as an Example of Technology Continuity Through the Middle Pleistocene(Springer Science and Business Media LLC, 2020) Méndez-Quintas, E.; Santonja, M.; Arnold, L.J.; Cunha-Ribeiro, J.P.; da Silva, P.X.; Demuro, M.; Duval, M.; Gomes, A.; Meireles, J.; Monteiro-Rodrigues, S.; Pérez-González, A.This article provides a synthesis of the Middle Pleistocene hominin record of West Iberia, which comprises sites displaying abundant concentrations of large flake Acheulean (LFA) assemblages, as well as isolated examples of Early Middle Palaeolithic (EMP) technology. These sites typically have age ranges spanning marine isotopic stages (MIS) 11–6, within the second half of the Middle Pleistocene, and are primarily located in fluvial environments related to the main regional river basins. The LFA sites display extensive occurrences of handaxes and cleavers on flake blanks (detached from large cores), with a large number of knapping remains, such as flakes or small-medium cores, showing simple reduction patterns. Over the identified age range of these sites, especially during the MIS 9–6 interval, we observe constant technological stability, without strong variations over time, and independent of the functionality of individual sites. These fixed technological and behavioural patterns reinforce the African affinities of the southwestern European Acheulean, in contrast to Acheulean assemblages identified in the northernmost areas of Europe.Item Open Access Spread of biological invasions: The experience of Tilapia species in the Shadegan Wetland, southwest of Iran(Zenodo, 2023) Valikhani, H.; Abdoli, A.; Nejat, F.; Khosravi, M.; Khezri, K.; Kiabi, B.H.The status of non-native tilapia species was evaluated by sampling campaigns in fishing grounds in the central part of the Shadegan Wetland, southwest Iran in 2014–15 (with follow-up in 2019). Considering a high percentage of relative species abundance, the tilapia species (Coptodon zillii and Oreochromis aureus) are well established in the wetland. As the management plans of such species are difficult and expensive, prevention of the introduction of these species to other water bodies is highly recommended.Item Open Access Where to fish in the forest? Tree characteristics and contiguous seagrass features predict mangrove forest quality for fishes and crustaceans(Wiley, 2023) Wanjiru, C.; Nagelkerken, I.; Rueckert, S.; Harcourt, W.; Huxham, M.1. Mangroves often support rich fish and crustacean communities, although faunal abundance and diversity show strong spatiotemporal variability. Consistent patterns in mangrove animal communities might be dictated by forest characteristics, by seascape context or by some combination of these factors. Predicting drivers of spatial heterogeneity in mangrove faunal communities can better support the zoning of forests for management purposes, for example by identifying sites important for fisheries nursery provision. 2. We sampled 14 sites within a large (4000 ha) mangrove forest in Kenya, quarterly over a period of 2 years. There were clear and consistent differences in the quality of sites for fish and crustacean abundance and diversity. 3. Forest characteristics (as summarised by the complexity index, CI) and seascape metrics (the presence, area and configuration of contiguous seagrass) were strong predictors of site differences. However, they showed opposite influences on dominant members of the fish and crustacean faunas, with CI correlated negatively with fishes and positively with crustaceans, and seagrass area correlated positively with fishes and negatively with crustaceans. 4. Synthesis and applications. Sites within the same mangrove forest exhibit consistent differences in fish and crustacean abundance. However, the fish and crustacean communities (and particularly dominant species within them) act differently in response to forest and seascape characteristics. Old growth, mature forest, set in a seascape of seagrass patches with bare sediment, was associated with highest crustacean abundance. In contrast, denser smaller trees and seascapes with larger, continuous areas of seagrass correlated better with fish abundance. Zoning for management, as mandated in new Kenyan policy, will need to consider these differences in seascape use between fish and crustaceans.Item Metadata only The world's longest known parallel temperature dataset: A comparison between daily Glaisher and Stevenson screen temperature data at Adelaide, Australia, 1887–1947(Wiley, 2022) Ashcroft, L.; Trewin, B.; Benoy, M.; Ray, D.; Courtney, C.Weather observing stations are subject to changes in instrumentation, location and surrounding environment over time. Parallel observations between old and new conditions are therefore vital to ensure that a reliable dataset can be built and used for long-term climate analysis. Here, we examine the world's longest known sets of parallel temperature observations: daily data for Adelaide, South Australia, recorded using two different thermometer screens for 60 years from 1887 to 1947. These data are globally significant for their length and completeness, but the daily observations in the Glaisher stand have only recently been digitized for analysis. We find maximum temperatures recorded in the Glaisher stand are warmer than the Stevenson screen observations, with the difference increasing with absolute temperature, while minimum temperatures recorded in the Glaisher stand are consistently slightly cooler. These differences are similar to those identified using monthly means, as well as other studies of shorter datasets. However, the daily resolution enabled us to identify periods of inconsistent relationships due to changes in observations times (particularly from 1938 onwards), and quantify the differences during extreme events. In particular, percentile analysis revealed that the differences for extremely high temperatures are only slightly greater than the average difference during the warmer months. The data provide an opportunity to attempt the development of 160-year continuous daily temperature record for one of the oldest colonial cities in the Southern Hemisphere. As expected, we find temperatures in recent decades to be the highest since 1859, although the Glaisher stand maximum temperature data in the 1860s are notably warm, likely due to dry conditions and persistent inhomogeneities. While the relationships we have identified cannot be applied to other 19th century Glaisher stand observations without careful metadata examination, they provide a possible tool for analysis and re-examination of historical midlatitude temperature observations elsewhere around the world.Item Open Access Understanding Traditional Chinese Medicine to strengthen conservation outcomes(Wiley, 2021) Cheung, H.; Doughty, H.; Hinsley, A.; Hsu, E.; Lee, T.M.; Milner-Gulland, E.J.; Possingham, H.P.; Biggs, D.; Molnar, Z.1. Numerous treatments in Traditional Chinese Medicine (TCM) involve the use of wildlife products, including some that utilize ingredients derived from endangered flora and fauna. Demand for such endangered wildlife products in TCM can threaten the survival of species and pose serious challenges for conservation. 2. Chinese medical practice is embedded in the cultural fabric of many societies in East and Southeast Asia, and remains an integral part of everyday life and knowledge. It is grounded in principles and theories that have grown over hundreds of years and differ substantially from those of mainstream allopathic biomedicine. 3. In order to address the threats posed by the medicinal consumption of endangered wildlife, conservation scientists and practitioners will benefit from a basic understanding of TCM. Such knowledge will enable conservationists to craft culturally nuanced solutions and to engage constructively with TCM stakeholders. However, conservationists typically lack familiarity with TCM as the incompatibility of many TCM concepts with those of the biomedical sciences poses a barrier to understanding. 4. In this paper, we examine the core theories and practices of TCM in order to make TCM more accessible to conservation scientists and practitioners. A better understanding of TCM will enable conservationists to deliver more effective and lasting conservation outcomes.Item Metadata only Using apatite to resolve the age and protoliths of mid-crustal shear zones: A case study from the Taxaquara Shear Zone, SE Brazil(Elsevier BV, 2020) Ribeiro, B.V.; Mulder, J.A.; Faleiros, F.M.; Kirkland, C.L.; Cawood, P.A.; O'Sullivan, G.; Campanha, G.A.C.; Finch, M.A.; Weinberg, R.F.; Nebel, O.Shear zones accommodate strain and facilitate migration of hydrothermal fluid and magma through the crust. Unravelling the deformation history of shear zones requires correspondence between the closure temperature of mineral geochronometers and the temperature of deformation. Here, we adopt apatite U–Pb-trace element analysis as a tool for dating deformation and tracing the protoliths of mid-crustal shear zones through a case study of the Taxaquara Shear Zone (TSZ), a major transpressional shear zone in the southern Ribeira Belt of SE Brazil. Apatite from mylonites in the TSZ yield U–Pb ages of 558–536 Ma, considering uncertiainties, which slightly overlap with 40Ar/39Ar ages of 538 ± 2 Ma from muscovite in the lower limit. The closure temperature of apatite is estimated at 500–460 °C, which is slightly higher than that estimated for syn-kinematic muscovite (445–420 °C). Apatite from shear zone mylonites has Sr/Y and LREE systematics typical of apatite from S- and I-type granitoids, suggesting the adjacent and undeformed Pilar do Sul and Piedade granites are the likely protoliths of the mylonites. This interpretation is supported by new U–Pb ages of ca. 605 Ma from prekinematic zircon and titanite from mylonites, which corresponds closely with new U–Pb apatite ages and previously published U–Pb monazites ages from the Pilar do Sul Granite. We suggest the U–Pb system of apatite in the TSZ was reset via volume diffusion during rapid cooling given that it preserves the igneous geochemical signatures. Moreover, this interpretation is consistent with the lower apatite closure temperature (500–460 °C) relatively to the temperature of deformation (530–480 °C). The revised ~560–535 Ma age for the TSZ demonstrates that it post-dates the collisional phase of the Ribeira Belt (620–595 Ma and 595–565 Ma), indicating protracted strain accommodation during the Brasiliano–Pan African orogeny, and supports correlation with the 600–550 Ma and 570–550 Ma transpressional Dom Feliciano and Kaoko Belts. This study demonstrates that apatite is a powerful tool for unravelling the history of mid-crustal shear zones as it is stable in a wide range of lithotypes, has trace element compositions that are sensitive to the environment of formation, and Pb closure temperatures typical of mid-crust conditions. U–Pb-trace element analysis of apatite provides a robust means to date shear zones that can be complimentary to, or independent of, more traditional 40Ar/39Ar analysis of mica or amphibole.Item Metadata only A long-lived active margin revealed by zircon U-Pb-Hf data from the Rio Apa Terrane (Brazil): New insights into the Paleoproterozoic evolution of the Amazonian Craton(Elsevier BV, 2020) Ribeiro, B.V.; Cawood, P.A.; Faleiros, F.M.; Mulder, J.A.; Martin, E.; Finch, M.A.; Raveggi, M.; Teixeira, W.; Cordani, U.G.; Pavan, M.We present the first regional in-situ zircon U–Pb–Hf isotopic data from metaigneous and metasedimentary rocks from the Paleo- to Mesoproterozoic Rio Apa Terrane (RAT), a crustal fragment outcropping in the central-western Brazil and north-eastern Paraguay. These new ages and Hf isotopic data delineate three magmatic events, which record the construction of the temporally and isotopically distinct Western and Eastern Terranes of the RAT. The Western Terrane comprises the 2100–1940 Ma Porto Murtinho Complex and the 1900–1840 Ma Amoguijá Belt, which both define a crustal reworking array in εHfT-time space evolving from a precursor source with Hf TDM age of ca. 2700 Ma. The 1800–1720 Ma Caracol Belt constitutes the Eastern Terrane and yields suprachondritic εHfT signatures up to +7.1, indicating significant juvenile input. The metasedimentary Amolar Group and Rio Naitaca Formation in the Western Terrane have maximum depositional ages of 1850–1800 Ma and subchondritic εHfT signatures down to −5.7, similar to the underlying basement of the Amoguijá Belt. In the Eastern Terrane, the Alto Tererê Formation has a maximum depositional age of 1750 Ma and mostly suprachondritic εHfT signatures, similar to magmatic rocks of the underlying Caracol Belt. Together, the new igneous and detrital zircon age and Hf isotopic data record a temporal and spatial transition from 2100 to 1840 Ma crustal reworking in the west to more juvenile magmatism at 1800–1720 Ma in the east. This transition is interpreted to reflect convergent margin magmatism associated with periods of subduction zone advance and retreat in an accretionary orogenic setting. Comparison of the εHfT-time signature of the RAT with the Amazonian Craton suggest penecontemporaneous development, with the Western and Eastern Terranes of the RAT being correlative with the Ventuari-Tapajós and Rio Negro-Juruena Province of the Amazonian Craton, respectively. Our new data also reveal that the εHfT signatures of the RAT are distinct from the Maz terrane, which refutes the MARA Block hypothesis.Item Open Access Phylogeography of a widespread Australian freshwater fish, western carp gudgeon (Eleotridae: Hypseleotris klunzingeri): Cryptic species, hybrid zones, and strong intra-specific divergences(Wiley, 2023) Unmack, P.J.; Cook, B.D.; Johnson, J.B.; Hammer, M.P.; Adams, M.Despite belonging to the most abundant and widespread genus of freshwater fishes in the region, the carp gudgeons of eastern Australia (genus Hypseleotris) have proved taxonomically and ecologically problematic to science since the 19th century. Several molecular studies and a recent taxonomic revision have now shed light on the complex biology and evolutionary history that underlies this group. These studies have demonstrated that carp gudgeons include a sexual/unisexual complex (five sexual species plus an assortment of hemiclonal lineages), many members of which also co-occur with an independent sexual relative, the western carp gudgeon (H. klunzingeri). Here, we fill yet another knowledge gap for this important group by presenting a detailed molecular phylogeographic assessment of the western carp gudgeon across its entire and extensive geographic range. We use a suite of nuclear genetic markers (SNPs and allozymes) plus a matrilineal genealogy (cytb) to demonstrate that H. klunzingeri s.l. also displays considerable taxonomic and phylogeographic complexity. All molecular datasets concur in recognizing the presence of multiple candidate species, two instances of historic between-species admixture, and the existence of a natural hybrid zone between two of the three candidate species found in the Murray-Darling Basin. We also discuss the major phylogeographic patterns evident within each taxon. Together, these analyses provide a robust molecular, taxonomic, and distributional framework to underpin future morphological and ecological investigations on this prominent member of regional freshwater ecosystems in eastern Australia.Item Metadata only Oxidative dissolution of sulfide minerals in single and mixed sulfide systems under simulated acid and metalliferous drainage conditions(American Chemical Society, 2021) Qian, G.; Fan, R.; Huang, J.; Pring, A.; Harmer, S.L.; Zhang, H.; Rea, M.A.D.; Brugger, J.; Teasdale, P.R.; Gibson, C.T.; Schumann, R.C.; Smart, R.S.C.; Gerson, A.R.Chalcopyrite, galena, and sphalerite commonly coexist with pyrite in sulfidic waste rocks. The aim of this work was to investigate their impact, potentially by galvanic interaction, on pyrite oxidation and acid generation rates under simulated acid and metalliferous drainage conditions. Kinetic leach column experiments using single-minerals and pyrite with one or two of the other sulfide minerals were carried out at realistic sulfide contents (total sulfide <5.2 wt % for mixed sulfide experiments), mimicking sulfidic waste rock conditions. Chalcopyrite was found to be most effective in limiting pyrite oxidation and acid generation with 77-95% reduction in pyrite oxidation over 72 weeks, delaying decrease in leachate pH. Sphalerite had the least impact with reduction of pyrite dissolution by 26% over 72 weeks, likely because of the large band gap and poor conductivity of sphalerite. Galena had a smaller impact than chalcopyrite on pyrite oxidation, despite their similar band gaps, possibly because of the greater extent of oxidation and the significantly reduced surface areas of galena (area reductions of >47% for galena vs <1.5% for chalcopyrite) over 72 weeks. The results are directly relevant to mine waste storage and confirm that the galvanic interaction plays a role in controlling acid generation in multisulfide waste even at low sulfide contents (several wt %) with small probabilities (≤0.23%) of direct contact between sulfide minerals in mixed sulfide experiments.Item Open Access Assessing connectivity in South Australia's Marine Parks Network(Government of South Australia, 2018) Jones, A.R.; Waycott, M.; Bryars, S.; Wright, A.; Gillanders, B.; Department of Environment, Water and Natural ResourcesItem Open Access The palaeoenvironment of the Upper Cretaceous (Cenomanian-Turonian) portion of the Winton Formation, Queensland, Australia(PeerJ, 2018) Fletcher, T.L.; Moss, P.T.; Salisbury, S.W.The Winton Formation is increasingly recognised as an important source of information about the Cretaceous of Australia, and, more broadly, the palaeobiogeographic history of eastern Gondwana. With more precise dating and stratigraphic controls starting to provide temporal context to the geological and palaeontological understanding of this formation, it is timely to reassess the palaeoenvironment in which it was deposited. This new understanding helps to further differentiate the upper, most-studied portion of the formation (Cenomanian–Turonian) from the lower portions (Albian–Cenomanian), allowing a coherent picture of the ecosystem to emerge. Temperatures during the deposition of the Upper Cretaceous portion of the Winton Formation were warm, with high, seasonal rainfall, but not as extreme as the modern monsoon. The landscape was heterogeneous, a freshwater alluvial plain bestrode by low energy, meandering rivers, minor lakes and mires. Infrequent, scouring flood events were part of a multi-year cycle of drier and wetter years. The heavily vegetated flood plains supported abundant large herbivores. This was the final infilling of the great Eromanga Basin.