45 results
Search Results
2. Reflections from the Field: Country in a Plastic Bag.
- Author
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Nova, Stephen
- Subjects
PLASTIC bags ,SHIPPING containers ,ABORIGINAL Australians ,CULTURAL property ,ARCHAEOLOGICAL excavations ,CONTAINER ships ,NONPROFIT sector - Abstract
Australian mining projects frequently undertake cultural salvage, involving archaeological consultants and Aboriginal Elders to identify important artefacts. However, the storage conditions within shipping containers present challenges, such as weather, insects, and limited access for Traditional Owners. The author, reflecting on his experience working as a project heritage advisor in Western Australia's Pilbara region, emphasises the need for collaborative engagement between the mining sector and Aboriginal communities to develop effective storage strategies that prioritise both scientific integrity and cultural significance. The author raises questions about the purpose and sustainability of storing cultural artefacts in containers, while highlighting the need to balance safeguarding heritage with the evolving needs of Indigenous communities. Ultimately, the author emphasises the importance of empowering Traditional Owners in decisions about artefact storage and engaging in meaningful consultation to preserve cultural heritage. The author suggests that the process should prioritise not just tangible artefacts but also intangible aspects like stories and songlines that make up the living Indigenous culture. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Research priorities for the ghost bat (Macroderma gigas) in the Pilbara region of Western Australia.
- Author
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Cramer, Viki A., Armstrong, Kyle N., Bullen, Robert D., Cross, Sophie L., Gibson, Lesley, Hanrahan, Nicola, Knuckey, Chris G., Ottewell, Kym, Reiffer, Scott, Ruykys, Laura, Shaw, Robyn E., Thavornkanlapachai, Rujiporn, Thompson, Scott A., Wild, Suzi, and van Leeuwen, Stephen
- Subjects
BATS ,FERAL cats ,HABITAT destruction ,FEDERAL legislation ,MINERAL industries ,GOVERNMENT agencies - Abstract
The ghost bat (Macroderma gigas) is Australia's largest echolocating bat. It is restricted to several disjunct populations in the north of the continent, including a population in the Pilbara region of Western Australia. In 2016 the ghost bat was listed as Vulnerable under Australian federal legislation, owing to declining numbers across many regional populations. The most severe threat to ghost bats in the Pilbara region is the destruction and disturbance of habitat due to mining operations, but disturbance to their roosts from other infrastructure developments and changes to and loss of foraging habitat also pose significant threats. A set of research priorities for ghost bats in the Pilbara was developed during a workshop attended by mining industry representatives, environmental consultants, scientists and government regulators. Five research priorities were identified: (1) identify and characterise critical diurnal roosts and foraging habitat; (2) improve knowledge of the distribution, movement and dispersal patterns of ghost bats in the region; (3) improve knowledge of population size, persistence and long-term trends; (4) better understand the cumulative, direct and indirect impacts of mining and other development activities; and (5) better understand the threats posed by fence entanglements, cane toads and feral cats. The ghost bat (Macroderma gigas) is Australia's largest echolocating bat and one of its most distinctive. Ghost bats are under threat across northern Australia owing to activities such as mining and infrastructure development that destroys their roosts, vegetation clearing and grazing that diminishes their food resources, and the invasion of poisonous cane toads. This paper outlines research priorities for ghost bats in the Pilbara region, developed through a workshop involving scientists and representatives from the mining industry and government agencies. Photograph by Bruce Thomson. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Sustainable Water in Mining? The Importance of Traditional Owner Involvement in Commercial Water Use and Management in the Pilbara Region of Western Australia.
- Author
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Garlett, Emma and Holcombe, Sarah
- Subjects
- *
MINE water , *WATER management , *WATER use , *IRON mining , *GAS well drilling - Abstract
The mining industry is a significant water user, an issue that gains a particular prominence in arid zone mining regions, such as the Pilbara region in Western Australia (WA). Mining companies extract vast amounts of water from the groundwater aquifers to access orebodies and to dewater the mine pits. Much of this water is dumped in creeks, injected back into the aquifer downstream or used in mining processing. There is increased awareness from community members for sustainable water use in mining beyond life of mine, and the emergence of Environmental, Social and Governance (ESG) principles in the mining and metals sector signals a shift towards recognizing the importance of water stewardship. Much of the land subject to dewatering in the Pilbara is also subject to native title determinations. For Traditional Owners, important cultural values are associated with water. However, water is not adequately covered in native title, especially in relation to commercial use. We argue that Traditional Owner involvement in design and management of the use of excess water from a mining proponent's water licence (dewatering) can assist in sustainable use of groundwater, as well as provide opportunities in social and economic enterprises. As a provocation style piece, this paper is based on secondary literature, rather than ethnographic data. It explores the political and regulatory landscape of mine dewatering and outlines the limitations that have existed historically and currently and which inhibit Traditional Owners to participate in water management or commercial water interests. We also provide a high‐level analysis of several mining proponents' public policy commitments to water stewardship to assess the sustainable use of water which involves stakeholders such as Traditional Owners in water decision‐making. Finally, we identify possible opportunities and provide some recommendations, for water futures in this dry region where iron ore mining and gas extraction, already massive, are expanding further. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Use of expert elicitation in the field of occupational hygiene: Comparison of expert and observed data distributions.
- Author
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Lowry, David Michael, Fritschi, Lin, Mullins, Benjamin J., and O'Leary, Rebecca A.
- Subjects
DATA distribution ,HYGIENE ,OCCUPATIONAL roles ,BETA distribution ,JUDGMENT (Psychology) ,CHANNEL estimation ,POLLUTANTS - Abstract
The concept of professional judgement underpins the way in which an occupational hygienist assesses an exposure problem. Despite the importance placed on professional judgement in the discipline, a method of assessment to characterise accuracy has not been available. In this paper, we assess the professional judgement of four occupational hygienists ('experts') when completing exposure assessments on a range of airborne contaminants across a number of job roles within a surface mining environment in the Pilbara region of Western Australia. The job roles assessed were project driller, mobile equipment operator, fixed plant maintainer, and drill and blast operator. The contaminants of interest were respirable crystalline silica, respirable dust, and inhalable dust. The novel approach of eliciting exposure estimates focusing on contaminant concentration and attribution of an exposure standard estimate was used. The majority of the elicited values were highly skewed; therefore, a scaled Beta distribution were fitted. These elicited fitted distributions were then compared to measured data distributions, the results of which had been collected as part of an occupational hygiene program assessing full-shift exposures to the same contaminants and job roles assessed by the experts. Our findings suggest that the participating experts within this study tended to overestimate exposures. In addition, the participating experts were more accurate at estimating percentage of an exposure standard than contaminant concentration. We demonstrate that this elicitation approach and the encoding methodology contained within can be applied to assess accuracy of exposure judgements which will impact on worker protection and occupational health outcomes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Earth's oldest tsunami deposit? Early Archaean high‐energy sediments in the ca 3.48 Ga Dresser Formation (Pilbara, Western Australia).
- Author
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Runge, Eric A., Duda, Jan‐Peter, Van Kranendonk, Martin J., and Reitner, Joachim
- Subjects
ARCHAEAN ,SEDIMENTATION & deposition ,VOLCANIC eruptions ,CALDERAS ,TSUNAMIS ,PLANETARY surfaces - Abstract
Dynamic sedimentary processes are a key parameter for establishing the habitability of planetary surface environments on Earth and beyond and thus critical for reconstructing the early evolution of life on our planet. This paper presents a sedimentary section from the ca 3.48 Ga Dresser Formation (Pilbara Craton, Western Australia) that contains high‐energy reworked sediments, possibly representing the oldest reported tsunami deposit on Earth to date. Field and petrographic evidence (e.g. up to 20 cm large imbricated clasts, hummocky bedding, Bouma‐type graded sequences) indicate that the high‐energy deposit represents a bi‐directional succession of two debrite–turbidite couplets. This succession can best be explained by deposition related to passage and rebound of tsunami waves. Sedimentary processes were possibly influenced by highly dense silica‐rich seawater. The tsunami was probably triggered by local fault‐induced seismic activity since the Dresser Formation was deposited in a volcanic caldera basin that experienced syndepositional extensional growth faulting. However, alternative triggers (meteorite impact, volcanic eruption) or a combination thereof cannot be excluded. The results of this work indicate a subaquatic habitat that was subject to tsunami‐induced high‐energy disturbance. Potentially, this was a common situation on the early Archaean Earth, which experienced frequent impacts of extraterrestrial bodies. This study thus adds to the scarce record of early Archaean high‐energy deposits and stresses the relevance of high‐energy depositional events for the early evolution of life on Earth. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. Tracing pathways: writing archaeology in Nyiyaparli country.
- Author
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BIRD, CAROLINE, HOOK, FIONA, and RHOADS, JAMES W.
- Subjects
ARCHAEOLOGY ,ARCHAEOLOGICAL surveying ,ARCHAEOLOGICAL excavations ,ABORIGINAL Australians ,CULTURAL landscapes - Abstract
Copyright of Archaeology in Oceania is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
- Full Text
- View/download PDF
8. Depth‐Resolved Groundwater Chemistry by Longitudinal Sampling of Ambient and Pumped Flows Within Long‐Screened and Open Borehole Wells.
- Author
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Poulsen, David L., Cook, Peter G., Simmons, Craig T., Solomon, D. Kip, and Dogramaci, Shawan
- Subjects
CHEMISTRY ,RESOLUTION (Chemistry) ,GROUNDWATER ,GROUNDWATER sampling ,WATER depth ,FLOW measurement - Abstract
Depth‐resolved chemistry samples are critical to a wide range of groundwater investigations. If a well intersects zones of variable concentrations, a pumped sample is a composite of the inflows, which mix in the well. Where discrete concentrations are required, excessive mixing makes samples less useful and potentially misleading. However, installations for depth‐discrete sampling are expensive, particularly for regional studies, so sometimes there is incentive to use existing infrastructure designed for other purposes (e.g., supply wells). This paper shows how the resolution of groundwater chemistry derived from long‐screened and open borehole wells can be improved by measuring and sampling the in‐well vertical flow regimes in ambient (unpumped) and/or pumped conditions. The ambient flow regime, driven by a natural vertical head gradient, is shown to be particularly useful to sample groundwater native to defined inflow zones (head in the zone > head in the well) and avoid zones impacted by the invasion of intraborehole flow (head in the zone < head in the well). Depth‐specific samples are interpreted either as native groundwater from a discrete source, subject only to analytical error, or a mixture from multiple sources that can be deconvolved, incorporating error in both flow and concentration measurements. Depth‐resolved age tracers (chlorofluorocarbons, 14C, and He) in groundwater from three supply wells are verified with samples from a multidepth nest of piezometers. Results show old groundwater at all depths and the simultaneous occurrence of young water at shallower depths in undisturbed dual‐porosity fractured aquifers in the Pilbara region of Western Australia. Key Points: Sampling ambient vertical flows can provide more insightful data than sampling pumped flowsAmbient flows can be sampled without purging or pumping the wellIn‐well samples are either from a discrete source or the mixture that can be deconvolved [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
9. Anomaly detection in Fourier transform infrared spectroscopy of geological specimens using variational autoencoders.
- Author
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Gonzalez, C.M., Horrocks, T., Wedge, D., Holden, E.J., Hackman, N., and Green, T.
- Subjects
- *
FOURIER transform infrared spectroscopy , *ANOMALY detection (Computer security) , *BANDED iron formations , *FERRIC oxide , *ALUMINUM oxide , *SEDIMENT sampling - Abstract
[Display omitted] • Employed a Variational Autoencoder (VAE) to detect anomalies in spectra. • Generate artificial spectra and calculate probability it came from the original spectra. • Spectrum, geochemistry, and latent space combined to analyse anomalous data. • Spectra, Geochemistry, with the VAE act as a powerful anomaly detection tool in unsupervised settings. Fourier Transform infrared spectroscopy (FTIR) is an emerging cost effective and rapid mineralogical characterization technique being applied in the geosciences. Detecting anomalous FTIR spectra is especially relevant to the geoscience domain, as it may indicate abrupt changes in geology or mineralogical composition of the rock sample being examined. Given a large volume of data, detecting anomalies that exhibit significant and abrupt spatial and compositional variability is a time-consuming and challenging task. This paper explores the use of an unsupervised variational autoencoder (VAE) for determining anomalies that may exist within a set of FTIR spectra collected from reverse circulation (RC) drill chip samples spanning several iron ore deposits from the Pilbara region in Western Australia. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were measured from 1,579 two-metre composite samples. Our results showed that the VAE was effective in separating anomalous spectra from spectra typical of unmineralized banded iron formation by leveraging the probabilistic latent representation of the spectra in as few as two latent dimensions. To validate our results, detected anomalous samples were compared with their respective geochemical assays to analyse their mineralogical differences, which may have led to the anomalous spectra. In the iron ore sample data used in this study, the observed spectral anomalies were shown to have elevated concentrations of Al 2 O 3 and TiO 2 wt.% while being several standard deviations below the mean Fe 2 O 3 wt.% indicating mineralogies rich in shale as opposed to iron oxide rich mineralogies. While the paper demonstrates the efficacy of the VAE in anomaly detection, it can also be effective in assuring the quality of the FTIR data as a pre-processing step, which is critically important for machine learning applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
10. Assessment of natural hydrogen systems in Western Australia.
- Author
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Rezaee, Reza
- Subjects
- *
RESERVOIR rocks , *HYDROGEN , *MINERALS in water , *REMOTE-sensing images , *SEDIMENTARY rocks - Abstract
The discovery of a large accumulation of natural hydrogen in Mali has triggered the opportunity to search for hydrogen accumulations in other countries. The generation of hydrogen in Mali is linked to the presence of very old iron-rich basement rocks. Solid-liquid redox reactions between iron-rich minerals and groundwater are a possible source of H 2 in deep basement rocks. The hypothesis is that hydrogen degassing may result in the surface circular shallow depressions. The Archean iron-rich Yilgarn and Pilbara cratons that cover a vast area of Western Australia contain abundant iron-rich mafic-ultramafic rocks. The craton reveals many surficial circular depressions visible through satellite images. The area has abundant fault systems and is blanketed with Eocene sedimentary rocks containing high-quality reservoir rocks. All these characteristics appear to provide most of the required elements, such as a hydrogen source, migration pathway, and reservoir rock for a complete "Hydrogen System" to be developed in the area. • A natural "Hydrogen System" has been assessed for Western Australia in this paper. • Interactions between iron-rich minerals and water are a possible source of H 2. • The Archean Craton of WA reveals depressions that could be location of H 2 emission. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
11. Tropical cyclone impacts on the Western Australian coast and extreme wind speeds in Region D.
- Author
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Holmes, John
- Subjects
- *
WIND speed , *TROPICAL cyclones , *DISTRIBUTION (Probability theory) , *CYCLONES , *COASTS - Abstract
This paper reviews the numbers of tropical cyclones in the southern Indian Ocean, and the land-falling cyclones that have impacted the Pilbara and Gascoyne coastlines of Western Australia since 1970, with particular emphasis on those of Category 4 strength and above. It shows reductions in impacts of severe cyclones on that coastline in the most recent two decades. Nearly as many severe cyclones have impacted the coast outside the current northern boundary of Region D in AS/NZS 1170.2 as have occurred within that boundary, suggesting the limits of Region D may need reviewing. Recorded and corrected extreme wind gusts exceeding 22 m/s from eight coastal stations have been processed as a group, and individually for 3 stations with long records. This indicates that the extreme value distribution in the draft standard DR AS/NZS 1170.2:2020 is quite adequate, without any additional factors, but the predicted extreme wind speeds for Carnarvon are well under the Region D specifications. The calculated wind direction multipliers for Region D show higher values from east and northeast; this can be explained by the wind directions generated by the clockwise rotations created by the cyclonic vortices, as the storms cross the coastline, or as they pass along the coastline at near full strength. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
12. Commemorating the colonial Pilbara: beyond memorials into difficult history.
- Author
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Gregory, Kate and Paterson, Alistair
- Subjects
COLONIES ,IMPERIALISM ,MEMORIALIZATION ,SOCIAL history - Abstract
The colonial Northwest of Western Australia was a harsh frontier, where demands for Aboriginal land, labour and knowledge led to dispossession, loss of rights, massacre and generations encumbered with the colonial legacy. In the Pilbara, there are some rare attempts to engage with this difficult colonial history, mainly in the form of heritage site interpretation and heritage trails. Overall, the difficult colonial history of the Northwest is poorly represented. Colonialism and its legacy are not effectively commemorated, nor are distinct local cultural and civic attributes highlighted as ‘lessons from the past’. In this paper, we explore the memorialization and commemoration of the Northwest's traumatic colonial history and consider a history of how heritage has been represented across the landscape. We suggest that the affective heritage of the Northwest especially cross-cultural or multi-cultural sites and histories can provide a basis for commemorating difficult colonial history or violent events that are underrepresented in dominant heritage regimes. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
13. Archean (3.3 Ga) paleosols and paleoenvironments of Western Australia.
- Author
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Retallack, Gregory J. and Schmitz, Mark D.
- Subjects
PALEOPEDOLOGY ,FOSSIL microorganisms ,ARCHAEAN ,CARBON films ,IRON ,HYDROTHERMAL vents - Abstract
The Pilbara craton of northwestern Australia is known for what were, when reported, the oldest known microfossils and paleosols on Earth. Both interpretations are mired in controversy, and neither remain the oldest known. Both the microfossils and the paleosols have been considered hydrothermal artefacts: carbon films of vents and a large hydrothermal cupola, respectively. This study resampled and analyzed putative paleosols within and below the Strelley Pool Formation (3.3 Ga), at four classic locations: Strelley Pool, Steer Ridge, Trendall Ridge, and Streckfuss, and also at newly discovered outcrops near Marble Bar. The same sequence of sedimentary facies and paleosols was newly recognized unconformably above the locality for microfossils in chert of the Apex Basalt (3.5 Ga) near Marble Bar. The fossiliferous Apex chert was not a hydrothermal vein but a thick (15 m) sedimentary interbed within a sequence of pillow basalts, which form an angular unconformity capped by the same pre-Strelley paleosol and Strelley Pool Formation facies found elsewhere in the Pilbara region. Baritic alluvial paleosols within the Strelley Pool Formation include common microfossil spindles (cf. Eopoikilofusa) distinct from marine microfossil communities with septate filaments (Primaevifilum) of cherts in the Apex and Mt Ada Basalts. Phosphorus and iron depletion in paleosols within and below the Strelley Pool Formation are evidence of soil communities of stable landscapes living under an atmosphere of high CO
2 (2473 ± 134 ppmv or 8.8 ± 0.5 times preindustrial atmospheric level of 280 ppm) and low O2 (2181 ± 3018 ppmv or 0.01 ± 0.014 times modern). [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
14. Establishing Geomorphic Reference Criteria for Design of River Diversions Around Mine Pits in the Pilbara, Western Australia.
- Author
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Flatley, Alissa and Rutherfurd, Ian
- Subjects
REGULATION of rivers ,RIVER channels ,SHEARING force ,MINE closures ,MINING corporations ,BEDROCK - Abstract
Copyright of Mine Water & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
15. Empirical landscape genetic comparison of single nucleotide polymorphisms and microsatellites in three arid‐zone mammals with high dispersal capacity.
- Author
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Skey, Ebony D., Ottewell, Kym M., Spencer, Peter B., and Shaw, Robyn E.
- Subjects
SINGLE nucleotide polymorphisms ,MICROSATELLITE repeats ,LIFE history theory ,FRAGMENTED landscapes ,MAMMALS - Abstract
Landscape genetics is increasingly transitioning away from microsatellites, with single nucleotide polymorphisms (SNPs) providing increased resolution for detecting patterns of spatial‐genetic structure. This is particularly pertinent for research in arid‐zone mammals due to challenges associated with unique life history traits, such as boom‐bust population dynamics and long‐distance dispersal capacities. Here, we provide a case study comparing SNPs versus microsatellites for testing three explicit landscape genetic hypotheses (isolation‐by‐distance, isolation‐by‐barrier, and isolation‐by‐resistance) in a suite of small, arid‐zone mammals in the Pilbara region of Western Australia. Using clustering algorithms, Mantel tests, and linear mixed effects models, we compare functional connectivity between genetic marker types and across species, including one marsupial, Ningaui timealeyi, and two native rodents, Pseudomys chapmani and P. hermannsburgensis. SNPs resolved subtle genetic structuring not detected by microsatellites, particularly for N. timealeyi where two genetic clusters were identified. Furthermore, stronger signatures of isolation‐by‐distance and isolation‐by‐resistance were detected when using SNPs, and model selection based on SNPs tended to identify more complex resistance surfaces (i.e., composite surfaces of multiple environmental layers) in the best‐performing models. While we found limited evidence for physical barriers to dispersal across the Pilbara for all species, we found that topography, substrate, and soil moisture were the main environmental drivers shaping functional connectivity. Our study demonstrates that new analytical and genetic tools can provide novel ecological insights into arid landscapes, with potential application to conservation management through identifying dispersal corridors to mediate the impacts of ongoing habitat fragmentation in the region. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. Kurangara in Queensland?: A Critique of Duncan‐Kemp's Account.
- Author
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Nash, David
- Subjects
LITERATURE - Abstract
A particular historical travelling religious complex in northern Western Australia, usually known as Kurangara, has been the subject of anthropological attention since the late 1930s. Overlooked in all the literature is a similar account assigned to 1912–1918, in the distant Channel Country of southwest Queensland. This is in Alice Duncan‐Kemp's last book, published in 1968. My examination shows that a good deal of Duncan‐Kemp's account repeated parts of a 1954 popular magazine about Kurangara in the Pilbara. In other respects Duncan‐Kemp may have drawn on her own childhood experiences, but in the absence of corroboration her account has to be considered unreliable. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
17. Two new species of burrowing scorpions (Urodacidae: Urodacus) from the Pilbara region of Western Australia with identical external morphology.
- Author
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Buzatto, Bruno A., Clark, Huon L., Harvey, Mark S., and Volschenk, Erich S.
- Subjects
SCORPIONS ,MORPHOLOGY ,SEXUAL dimorphism ,SPECIES ,GENITALIA - Abstract
Two new species of urodacid scorpion are described from the Pilbara region in Western Australia, where they are both patchily distributed along creek lines in the north-east of the region. Urodacus uncinus sp. nov. and Urodacus lunatus sp. nov. are indistinguishable based on external morphology: adults are medium-sized, yellow burrowing scorpions with remarkable sexual dimorphism in the telson, in which males have a uniquely swollen vesicle and an aculeus that is more strongly curved than other known species of Urodacus. The species are superficially similar to Urodacus similis L.E. Koch, 1977 and Urodacus yaschenkoi Birula, 1903 in the morphology of the first four metasomal segments, which are extremely short and not much longer than high. The two new species can only be discerned from each other based on the morphology of their hemispermatophores, which highlights the extremely conserved morphology of species in the genus and suggests that many new species await description with careful examination of their genitalia. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Linking life history to landscape for threatened species conservation in a multiuse region.
- Author
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Shaw, Robyn E., Spencer, Peter B., Gibson, Lesley A., Dunlop, Judy A., Kinloch, Janine E., Mokany, Karel, Byrne, Margaret, Moritz, Craig, Davie, Harriet, Travouillon, Kenny J., and Ottewell, Kym M.
- Subjects
ENDANGERED species ,WILDLIFE conservation ,LIFE history theory ,ALLUVIAL plains ,LANDSCAPES ,HABITATS ,POPULATION dynamics - Abstract
Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
19. Long distance commuting: A tool to mitigate the impacts of the resources industries boom and bust cycle?
- Author
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Haslam McKenzie, Fiona
- Subjects
COMMUTING ,COMMUNITY development ,MINE closures ,INDUSTRIAL relations - Abstract
Western Australia experienced a prolonged resources boom for more than a decade commencing in 2001. The majority of mining industry employees commute long distances from their homes, living onsite in company accommodation and working compressed rosters for a prescribed period before commuting home again for furlough and recommencing the work and commute cycle. Many community leaders, politicians and businesses complain that company policies and industrial relations arrangements, which enabled long distance commuting (LDC), undermine regional economic development. They argue that the host communities closest to mining operations bear the brunt of globally driven boom and bust markets and experience many of the disadvantages but few of the opportunities associated with booms or busts, while source communities, particularly large cities, reap the benefits from repatriated salaries, increased populations and investment derived from mining activities in the host communities. This paper examines the role of long distance commuting as a tool for mitigating the impacts of the boom and bust cycles in the resources industries of Western Australia, focusing on the resources-rich region of the Pilbara. The paper will also speculate the social and economic impact on the mining communities and the state more broadly if government had capitulated and restricted long distance commuting. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
20. Application of a sustainability framework to enhance Australian food literacy programs in remote Western Australian communities.
- Author
-
Aberle, Leisha M., Platts, Julia R., Kioutis, Marie A., Haustead, Louise M., and Godrich, Stephanie L.
- Subjects
LITERACY programs ,COMMUNITIES ,SUSTAINABILITY ,LETTERS of intent ,ECOLOGICAL models - Abstract
Issue addressed: Food literacy programs aim to build individuals' knowledge, skills and self‐efficacy to adopt healthy food choices conducive to reducing the risk of chronic diseases, such as obesity. Foodbank WA's (FBWA) Healthy Food for All® nutrition programs have supported the improvement of food literacy knowledge and skills among vulnerable people living in the Pilbara. Methods: A Sustainability Framework containing ten sustainability factors was overlaid with social ecological model (SEM) levels of influence to form a matrix. The use of this matrix facilitated sustainability strategy appraisal within three food literacy programs delivered in remote WA. Results: Programs included multiple sustainability strategies across levels of influence; all programs addressed all ten sustainability factors at community and organisational SEM levels of influence. Few sustainability strategies were employed at the public policy level of influence. No program employed formal governance structures to guide program direction, such as steering groups; however, school and parent program staff developed Memoranda of Understanding to ensure the continuation of program delivery between the FBWA teams' regional visits. Conclusions: This study has showcased the comprehensive assessment of food literacy program sustainability across levels of influence and identified gaps for improvement by FBWA teams. So What?: The sustainability of food literacy programs aiming to increase knowledge and skills could be enhanced by conducting a similar analysis, during program planning or at program review. Using the matrix provides the opportunity to focus resources to address sustainability; supporting health promotion practitioners to transform the impacts of short‐term food literacy interventions into long‐term sustained outcomes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
21. Recent pegmatite-hosted spodumene discoveries in Western Australia: insights for lithium exploration in Australia and globally.
- Author
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Phelps-Barber, Zoe, Trench, Allan, and Groves, David I.
- Subjects
SPODUMENE ,GREENSTONE belts ,PEGMATITES ,CAPITAL market ,CRATONS - Abstract
The discovery and development of world-class Lithium–Caesium–Tantalum (LCT) spodumene-bearing pegmatites in Western Australia underpins growth of a significant new sector of its mining industry. Recently, several new spodumene discoveries have been delineated in the Yilgarn and Pilbara Cratons. Contrary to exploration narratives that new economic mineral discoveries will generally be made at increasingly greater depths, beneath barren cover rocks, or in remote geological environments, all new lithium discoveries have clear surface expressions in relatively 'mature' greenstone belts. The exploration implication is that the search space for pegmatite-hosted spodumene deposits in Western Australia remains immature. These recently discovered LCT pegmatites have geological features relevant to exploration including their age, amphibolite-facies metamorphic setting and syn-metamorphic timing, and 3D geometry, particularly their typically gentle dips, that match other such world-class pegmatites globally. Further spodumene discoveries within pegmatites at or near surface are likely in the Archean terranes of Western Australia based on these consistent exploration criteria and supportive capital market conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. Cryptic diversity down under: defining species in the subterranean amphipod genus Nedsia Barnard & Williams, 1995 (Hadzioidea: Eriopisidae) from the Pilbara, Western Australia.
- Author
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King, Rachael A., Fagan-Jeffries, Erinn P., Bradford, Tessa M., Stringer, Danielle N., Finston, Terrie L., Halse, Stuart A., Eberhard, Stefan M., Humphreys, Garth, Humphreys, Bill F., Austin, Andrew D., and Cooper, Steven J. B.
- Subjects
ENVIRONMENTAL impact analysis ,SPECIES ,GROUNDWATER monitoring ,POLLUTION monitoring - Abstract
Amphipod crustaceans comprise a significant and enigmatic component of Australian groundwater ecosystems, particularly in the Pilbara region of Western Australia. Many amphipod species in the Pilbara, including species in the genus Nedsia Barnard & Williams, 1995, are considered short range endemics, poorly or contentiously defined by taxonomic treatments based on morphology alone and have uncertain distributions as a consequence of this taxonomy. A modern systematic revision of Nedsia is presented here, utilising both molecular and morphological analyses alongside distributional data to delineate species. We describe 13 new species of Nedsia, confirm three existing species and synonymise eight previously described species. Nedsia species are confirmed to be functionally morphologically cryptic, with COI divergences at the 5–20% level. We present comparatively reduced taxonomic descriptions for these cryptic amphipod species in an effort to provide an accelerated pathway for future taxonomic work. The research provides the basis for future environmental impact assessments involving Nedsia species and ongoing monitoring of the groundwater communities these form part of in the resource-rich Pilbara region. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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23. Resolution of the Eremophila tietkensii (Scrophulariaceae) species complex based on congruence between morphological and molecular pattern analyses.
- Author
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Curtis, Amy L., Grierson, Pauline F., Batley, Jacqueline, Naaykens, Jeremy, Fowler, Rachael M., Severn-Ellis, Anita, and Thiele, Kevin R.
- Subjects
SCROPHULARIACEAE ,SPECIES ,MULTIVARIATE analysis ,HERBARIA - Abstract
Eremophila R.Br. comprises at least 238 species endemic to Australia, with many more having not yet been formally described. Three putative new taxa, namely, E. sp. Hamersley Range (K. Walker KW 136), E. sp. Calvert Range (A. A. Burbidge 738) and E. sp. Rudall River (P. G. Wilson 10512), were segregated from a broadly defined E. tietkensii F.Muell. & Tate by J. Hurter at the Western Australian Herbarium in 2012. Both E. sp. Hamersley Range and E. sp. Rudall River are listed as being of conservation concern in Western Australia, the former occurring in the Pilbara region in areas of prospective interest for mining development. We sought to determine whether these phrase-named entities should be formally described as new species, using multivariate analyses of morphometric and molecular data derived from specimens in the Western Australia Herbarium. Eremophila sp. Rudall River could not be adequately separated from E. tietkensii by either morphological or molecular data, and is here included within that species. By contrast, E. sp. Hamersley Range and E. sp. Calvert Range are clearly morphologically and genetically distinct. We thus describe them here as the new species E. naaykensii A.L.Curtis & K.R.Thiele and E. hurteri A.L.Curtis & K.R.Thiele. The recognition of these taxa will help inform their conservation prioritisation and subsequent management. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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24. Zircon U–Pb Geochronology and Hf–O Isotope Characteristics of Granitoids from the Capricorn Orogen, Western Australia.
- Author
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Jahn, I, Clark, C, Reddy, S, and Taylor, R J M
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GEOLOGICAL time scales ,GRANITE ,ZIRCON ,ISOTOPES ,ZIRCON analysis ,CRATONS - Abstract
The Capricorn Orogen, Western Australia, is a complex orogenic zone that records the convergence and collision of the Archaean Yilgarn and Pilbara cratons in forming the West Australian Craton (WAC), then over one billion years of subsequent intracontinental reworking. Granites associated with these tectonothermal events (the Dalgaringa, Bertibubba, Moorarie, Durlacher and Thirty Three supersuites) are exposed in the western part of the Capricorn Orogen. This study integrates radiogenic (U–Pb and Hf) and stable isotope (O) analysis of zircon grains from granitic rocks in the Capricorn Orogen to determine their ages and magmatic sources, including the relative contributions of mantle versus crustal material. Granites from the margin of the Yilgarn Craton record periods of crustal growth and reworking during the Archaean that influenced later Proterozoic magmatic events. Components of the Capricorn Orogen, collectively termed the Glenburgh Terrane, have previously been considered to be exotic to the adjacent Pilbara and Yilgarn cratons. However, new U–Pb zircon geochronology and Lu–Hf isotope compositions of basement rocks in the Glenburgh Terrane (the Halfway Gneiss) have similarities to some terranes of the Yilgarn Craton, and are interpreted to represent a reworked portion of the craton that was re-accreted during the Glenburgh Orogeny. Arc magmatism during the Ma Glenburgh Orogeny resulted in a period of crustal growth, with magmas representing a mixture of 50–90 % mantle-derived magmas and 50–10 % magmas derived from an evolved crustal component with an isotopic composition equivalent to that of the Halfway Gneiss. Following assembly of the WAC, granite magmatism in the Capricorn Orogen records a significant change from one dominated by mantle-derived magmatism to one dominated by crustal melting and an increased contribution from metasedimentary material. This transition reflects a geodynamic evolution from subduction–accretion to collision and intracratonic reworking. The isotopic characteristics of granites from the Moorarie Supersuite indicate three distinct sources: (1) a metasedimentary component; (2) an evolved crustal component, comparable with the Glenburgh Terrane; (3) a mafic juvenile component. Following this, the Hf–O compositions of the Durlacher Supersuite indicate that they were derived from reworking of the Moorarie Supersuite granites, and require no juvenile contribution or any additional sedimentary source. The isotopic compositions of the Thirty Three Supersuite pegmatites indicate that they were largely derived from reworking of the Moorarie and Durlacher supersuites. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
25. Bedding Angle Identification from BIF Marker Shales via Modified Dynamic Time Warping.
- Author
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George, Mark A., Silversides, Katherine L., Zigman, John, and Melkumyan, Arman
- Subjects
IRON ores ,SHALE ,ORE deposits ,ANGLES ,POINT set theory ,MATTRESSES - Abstract
When modelling a stratified orebody, accurately representing the dip and dip direction is important for accurate resource estimation. In the banded iron formation-hosted iron ore deposits in the Pilbara region of Western Australia, these quantities can be determined using marker shales from nearby holes. These marker shales are identified using natural gamma logs and are generally manually processed. Therefore, an automated method for matching natural gamma logs between holes is desirable. Dynamic time warping (DTW) can match two signals where there is stretching or distortion. This study presents a modified, iterative version of DTW for matching downhole natural gamma logs. This new method accounts for large differences in length of the two signals by comparing different segments of the signals. Several metrics were then used to rank potential matches between signals. The proposed iterative DTW method had an accuracy of 90%, compared with 67% for the standard DTW. Once matched, signals can be used to estimate the bedding angle at each hole. A point in one hole was matched to as many nearby holes as possible, creating a set of points located on the same surface. A localized plane was then fitted to these points. These bedding angles were used to reconstruct a surface representing the bedding. While the signal matching was accurate, the sparsity of correctly matched holes limits the accuracy of the calculated surface. Even with sparse gradient fields, a reasonable approximation of the bedding could be achieved. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
26. A framework of integrated research for managing introduced predators in the Pilbara bioregion, Western Australia.
- Author
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Moro, Dorian, Morris, Keith, van Leeuwen, Stephen, and Davie, Harriet
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INTRODUCED animals ,PREDATION ,WILD dogs ,FERAL cats ,PREDATOR management ,BIODIVERSITY conservation ,PREDATORY animals ,BIODIVERSITY - Abstract
The effective control of wild dogs, feral cats and foxes is of primary interest to land managers, both for biodiversity conservation and for the protection of livestock. Control programs primarily target single species within the context of biodiversity conservation or livestock practices, but their effectiveness in depressing predator densities is unclear because monitoring is limited or not conducted. Here, we review and discuss the outcomes of a workshop to identify research priorities for managing predation on native fauna by introduced predators in the Pilbara bioregion in Western Australia. We suggest that the control of introduced predators will be most effective if it is implemented at a landscape-scale comprising integrated predator management that considers interspecific (predator) interactions combined with standardised monitoring to measure the effectiveness and benefits of control. Four research themes were identified: (1) collation and collection of baseline data, (2) effective monitoring of introduced predators, (3) understanding functional (ecological) roles of introduced predators within the different ecosystem contexts, and (4) identifying novel complementary approaches to protect threatened species. These themes collectively include research areas that invest in foundational, ecological and alternative biological parameters in research to close knowledge gaps related to the functional roles of introduced predators in the landscape. Addressing these research themes will assist land managers to achieve outcomes that address the needs of both biodiversity conservation and pastoral production. This framework is timely given the ongoing investment in offset funding being mobilised in the region. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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27. Characterization of drilling-related noise and curvelet-based evaluation of seismic-interferometric reflections for imaging of iron-bearing formations in Pilbara, Western Australia.
- Author
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Chamarczuk, M, Malinowski, M, Draganov, D, Grant, A, Asgharzadeh, M, and Urosevic, M
- Subjects
NOISE ,SEISMIC waves ,INTERFEROMETRY ,SURFACE waves (Seismic waves) ,DATA structures ,OIL well drilling ,SPECTROGRAMS ,BOREHOLES ,INDUCED seismicity - Abstract
Here we analyse ambient noise (AN) data generated during drilling of exploration boreholes and recorded using a dense array deployed over one of the numerous shallow iron-ore mineralization targets in the Pilbara region (Western Australia). Drilling and drilling-related operations were reoccurring in a sequence as described by the drillers' field notes, which created the rare opportunity to analyse AN data in time segments when only one type of technical process was predominantly active. Consequently, most of the recorded AN sources did not overlap in time and space. We extract the recordings in 15-min-long segments matching the time-span of single field-note entry and identify individually acting AN sources associated with specific field operations. The temporal variations of noise spectrograms and AN cross-correlations show dependency on the sequence of a few consecutive field operations and specific frequency–amplitude patterns associated with single field operations. These changes are directly reflected by the events visible in the retrieved virtual-source gathers (VSG), implying significant changes in noise temporal and spatial stationarity. Some VSGs represent the mixed contributions of surface and air waves. To remove the contributions of these arrivals to the reflection imaging, we visually inspect all data and select only field operations acting as stationary-phase sources specifically for the reflection retrieval. This was done for different receiver configurations inside PilbArray, and as a result, we obtain a collection of VSGs containing coherent body-wave reflections. Database of visually inspected VSGs is used to develop and benchmark a semi-automatic curvelet-based method for accurate parametrization of the reflection events retrieved from passive data and to compare the imaging quality of the different field operations. Common-midpoint stacks from manually and automatically selected VSGs show reflectivity consistent with the one obtained from the active-source data and related to the structure hosting shallow iron mineralization. Our results demonstrate the capacity of AN seismic interferometry to retrieve body-wave reflections and image shallow mineralization. They also provide an intermediate step toward automating the passive reflection imaging with similar data sets. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
28. A rich fauna of subterranean short-range endemic Anillini (Coleoptera, Carabidae, Trechinae) from semi-arid regions of Western Australia.
- Author
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Giachino, Pier Mauro, Eberhard, Stefan, and Perina, Giulia
- Subjects
ARID regions ,GROUND beetles ,FOREST litter ,PROSPECTING ,RAIN forests ,BEETLES - Abstract
Globally, the great majority of Anillini species are endogean, adapted to live in the interstices of soil and leaf litter, while the extremely low vagility of these minute ground beetles gives rise to numerous shortrange endemic species. Until recently the Australian Anillini fauna was known only from leaf litter in rain forests and eucalypt forests in the wetter, forested regions of eastern and south eastern Australia, as well as Lord Howe and Norfolk islands. The first hypogean Anillini in Australia (17 species in six genera) were described in 2016 from mineral exploration drill holes in iron-ore bearing rocks of the Pilbara region in Western Australia, representing the first finding of the tribe deep underground in a semi-arid climate region. A further eight new genera and 20 new species are described herein, mostly from the Pilbara region as well as the semi-arid Kimberley and Goldfields regions; all were collected in mineral exploration drill holes. The following new genera are described: Erwinanillus gen. nov., Gregorydytes gen. nov., Pilbaraphanus gen. nov., Neoillaphanus gen. nov., Kimberleytyphlus gen. nov., Gilesdytes gen. nov., Pilbaradytes gen. nov., and Bylibaraphanus gen. nov. The following new species are described: Erwinanillus baehri sp. nov.; Gracilanillus hirsutus sp. nov., G. pannawonicanus sp. nov.; Gregorydytes ophthalmianus sp. nov.; Pilbaraphanus chichesterianus sp. nov., P. bilybarianus sp. nov.; Magnanillus firetalianus sp. nov., M. sabae sp. nov., M. salomonis sp. nov., M. regalis sp. nov., M. serenitatis sp. nov.; Neoillaphanus callawanus sp. nov.; Kimberleytyphlus carrboydianus sp. nov.; Austranillus jinayrianus sp. nov.; Gilesdytes pardooanus sp. nov., G. ethelianus sp. nov.; Pilbaradytes abydosianus sp. nov., P. webberianus sp. nov.; Bylibaraphanus cundalinianus sp. nov.; and Angustanillus armatus sp. nov. Identification keys are provided for all Australian anilline genera, and Western Australian species. All the described species are known from a single locality and qualify as short-range endemics. The Anillini are recognised as a significant and diverse element making up part of Western Australia's remarkable subterranean fauna, and whose conservation may potentially be impacted by mining developments. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
29. Trace Element Contents of Mantle-Derived Magmas Through Time.
- Author
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Barnes, Stephen J, Williams, Morgan, Smithies, R Hugh, Hanski, Eero, and Lowrey, Jack R
- Subjects
TRACE elements ,MAGMAS ,OCEANIC plateaus ,FLOOD basalts ,ARCHAEAN ,CRATONS - Abstract
A large compilation of quality-curated major and trace element data has been assembled to investigate how trace element patterns of mafic and ultramafic magmas have varied with time through particular settings from the Archean to the Phanerozoic, the primary objective being to recognise at what times particular patterns of variation emerge, and how similar these are to baseline data sets representing tectonic settings in the modern Earth. The most informative element combinations involve Nb, Th and the REE, where REE are represented by 'lambda' parameters describing slope and shape of patterns. Combinations of the ratios of Th, Nb, La and lambda values from Archean and early Proterozoic basalts and komatiites reveal a distinctive pattern that is common in most well-sampled terranes, defining a roughly linear trend in multi-dimensional space from compositions intermediate between modern n-MORB and primitive mantle at one end, towards compositions approximating middle-to-upper continental crust at the other. We ascribe this 'Variable Th/Nb' trend in most instances to varying degrees of crustal contamination of magmas with similar compositions to modern oceanic plateau basalts. Komatiites had slightly more depleted sources than basalts, consistent with the hypothesis of derivation from plume tails and heads, respectively. The most significant difference between Precambrian and Phanerozoic plume-derived basalts is that the distinctive OIB-like enriched source component appears to be largely missing from the Archean and Proterozoic geologic record, although isolated examples of OIB-like trace element characteristics are evident in datasets from even the oldest preserved greenstones. Phanerozoic intra-cratonic LIPs, such as the 260 Ma Emeishan LIP in China, have fundamentally different geochemical characteristics to Archean and Paleoproterozoic assemblages; the oldest Proterozoic LIP we have identified that has this type of 'modern' signal is the Midcontinent Rift at 1100 Ma. The data are consistent with plume tail sources having changed from being dominantly depleted in the Archean Earth to dominantly enriched in the Phanerozoic Earth, while plume head sources have hardly changed at all. Trace element patterns considered to be diagnostic of subduction are locally present but rare in Archean terranes and become more prevalent through the Proterozoic, although this conclusion is tempered by the large degree of overlap in compositional space between continental arc magmas and continental flood basalts. This overlap reflects the difficulty of distinguishing the effects of supra-subduction metasomatizm and flux melting from those of crustal contamination. Additional factors must also be borne in mind, particularly that trace element partitioning systematics may have been different in all environments in a hotter planet, and large-scale asthenospheric overturns might have been predominant over modern-style plumes in the Archean Earth. Some basaltic suites in particular Archean terranes, notably the western parts of both the Yilgarn and Pilbara cratons in Western Australia and parts of the Superior Craton, have restricted, but locally predominant, suites of basalts with characteristics akin to modern oceanic arcs, suggesting that some process similar to modern subduction was preserved in these particular belts. Ferropicrite magmas with distinctive characteristics typical of modern OIBs and some continental LIPs (notably Emeishan) are rare but locally predominant in some Archean and early Proterozoic terranes, implying that plume sources were beginning to be fertilised by enriched, probably subducted, components as far back as the Mesoarchean. We see no evidence for discontinuous secular changes in mantle-derived magmatism with time that could be ascribed to major mantle reorganisation events. The Archean–Proterozoic transition appears to be entirely gradational from this standpoint. The transition from Archean-style to Phanerozoic-style plume magmatism took place somewhere between 1900 Ma (age of the Circum-Superior komatiitic basalt suites) and 1100 Ma (the age of the Midcontinent Rift LIP). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Does aerial baiting for controlling feral cats in a heterogeneous landscape confer benefits to a threatened native meso-predator?
- Author
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Palmer, Russell, Anderson, Hannah, Richards, Brooke, Craig, Michael D., and Gibson, Lesley
- Subjects
FERAL cats ,PREDATION ,FELIDAE ,CATS ,RESOURCE allocation ,LANDSCAPES ,NATIONAL interest - Abstract
Introduced mammalian predators can have devastating impacts on recipient ecosystems and disrupt native predator–prey relationships. Feral cats (Felis catus) have been implicated in the decline and extinction of many Australian native species and developing effective and affordable methods to control them is a national priority. While there has been considerable progress in the lethal control of feral cats, effective management at landscape scales has proved challenging. Justification of the allocation of resources to feral cat control programs requires demonstration of the conservation benefit baiting provides to native species susceptible to cat predation. Here, we examined the effectiveness of a landscape-scale Eradicat® baiting program to protect threatened northern quolls (Dasyurus hallucatus) from feral cat predation in a heterogeneous rocky landscape in the Pilbara region of Western Australia. We used camera traps and GPS collars fitted to feral cats to monitor changes in activity patterns of feral cats and northern quolls at a baited treatment site and unbaited reference site over four years. Feral cat populations appeared to be naturally sparse in our study area, and camera trap monitoring showed no significant effect of baiting on cat detections. However, mortality rates of collared feral cats ranged from 18–33% after baiting, indicating that the program was reducing cat numbers. Our study demonstrated that feral cat baiting had a positive effect on northern quoll populations, with evidence of range expansion at the treatment site. We suggest that the rugged rocky habitat preferred by northern quolls in the Pilbara buffered them to some extent from feral cat predation, and baiting was sufficient to demonstrate a positive effect in this relatively short-term project. A more strategic approach to feral cat management is likely to be required in the longer-term to maximise the efficacy of control programs and thereby improve the conservation outlook for susceptible threatened fauna. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Repeated evolution of an undescribed morphotype of Rhagada (Gastropoda : Camaenidae) from the inland Pilbara, Western Australia.
- Author
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Hamilton, Zoë R.
- Subjects
DNA analysis ,GENES ,LANDFORMS ,GASTROPODA ,HOMOPLASY ,BIVALVE shells ,TAXONOMISTS - Abstract
An undescribed small, banded morphotype of Rhagada land snails occurs widely in the rocky inland Pilbara region, Western Australia. Phylogenetic analysis of mitochondrial COI and 16S rRNA genes revealed that this novel morphotype is polyphyletic, comprising four distinct major clades, with divergences up to 21.4% at COI. These clades are apparently morphologically cryptic, with no obvious shell differences. Two of these species are associated with the major clade of Rhagada in the Pilbara mainland, one of which appears to be a variant of the larger, more globose species R. pilbarana , which occurs within 20 km proximity. The other two small, banded species are phylogenetically distinct from each other and all other known Rhagada. This small, banded morphotype shows evidence for both plesiomorphy and homoplasy. The morphotype has evolved independently at least twice, and is associated with the reasonably uniform habitat and harsh conditions in the elevated hinterland of the inland Pilbara. The broad distribution of the inland, small, banded morphotype conforms to the pattern of broad-scale uniformity of shells of the more coastal species of Rhagada. Its repeated evolution, however, confirms that the morphological uniformity is not simply because of common ancestry, supporting the theory that shell form in Rhagada is adapted to a broadly homogenous environment. Shell morphology in this genus has been demonstrated on more than one occasion to have the potential to adapt to different available environments, and hence shells should be used with a degree of caution for taxonomic interpretation. Analysis of DNA reveals that a recently discovered form of Rhagada land snails in the Pilbara region of Western Australia is actually four species, with indistinguishable shells. This small, banded shell type has evolved multiple times, indicating that common shell form need not mean close relationship, and can thus mislead taxonomists. The uniformity of shell form over large areas of similar habitat is thus not due simply to common ancestry, but instead suggests adaptation to the local environment. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
32. Excess Air Correction of SF 6 and Other Dissolved Gases in Groundwater Impacted by Compressed Air From Drilling or Well Development.
- Author
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Poulsen, David L., Cook, Peter G., and Dogramaci, Shawan
- Subjects
COMPRESSED air ,AIR ,GASES ,GROUNDWATER recharge ,GROUNDWATER ,GROUNDWATER tracers - Abstract
Atmospheric gases that dissolve in groundwater at the time of recharge are valuable tracers of groundwater residence time, but corrections are sometimes required. Low‐solubility gases like SF6 are particularly susceptible to the effects of excess air, which is generally assumed to occur at the time of recharge. If after excess air correction SF6 is still elevated above the expected concentration for water in equilibrium with the atmosphere, this is often attributed to a terrigenic source. We propose that compressed air used during and after well installation is a potential source of excess air, which can sometimes explain elevated SF6 concentrations from wells drilled in the last few decades. This concept is demonstrated by correcting elevated SF6 and CFC‐12 measurements from 55 wells at field sites in the Pilbara region of Western Australia with up to 10 mL(STP)/kg of atmospheric air from the time of drilling (2006–2016). The resulting SF6 and CFC‐12 concentrations are consistent with recharge between 1950 and 1970 for most wells. Excess air in recharge from that period could not have contained enough SF6 to explain the measured concentrations. This decoupling of excess air from recharge is potentially also significant for other gaseous age tracers with limited solubility including SF5CF3, Halon 1301, 39Ar, 85Kr, and 81Kr. Key Points: Compressed air can be a source of excess dissolved gases in groundwaterExcess air from drilling might explain elevated SF6 in samples from wellsCorrections are sometimes possible using SF6‐CFC plots [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
33. Testing multiple substrates for terrestrial biodiversity monitoring using environmental DNA metabarcoding.
- Author
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Heyde, Mieke, Bunce, Michael, Wardell‐Johnson, Grant, Fernandes, Kristen, White, Nicole E., and Nevill, Paul
- Subjects
ENVIRONMENTAL monitoring ,BIODIVERSITY monitoring ,PLANT diversity ,MEDITERRANEAN climate ,COASTAL plains ,PLANT DNA - Abstract
Biological surveys based on visual identification of the biota are challenging, expensive and time consuming, yet crucial for effective biomonitoring. DNA metabarcoding is a rapidly developing technology that can also facilitate biological surveys. This method involves the use of next generation sequencing technology to determine the community composition of a sample. However, it is uncertain as to what biological substrate should be the primary focus of metabarcoding surveys. This study aims to test multiple sample substrates (soil, scat, plant material and bulk arthropods) to determine what organisms can be detected from each and where they overlap. Samples (n = 200) were collected in the Pilbara (hot desert climate) and Swan Coastal Plain (hot Mediterranean climate) regions of Western Australia. Soil samples yielded little plant or animal DNA, especially in the Pilbara, probably due to conditions not conducive to long‐term preservation. In contrast, scat samples contained the highest overall diversity with 131 plant, vertebrate and invertebrate families detected. Invertebrate and plant sequences were detected in the plant (86 families), pitfall (127 families) and vane trap (126 families) samples. In total, 278 families were recovered from the survey, 217 in the Swan Coastal Plain and 156 in the Pilbara. Aside from soil, 22%–43% of the families detected were unique to the particular substrate, and community composition varied significantly between substrates. These results demonstrate the importance of selecting appropriate metabarcoding substrates when undertaking terrestrial surveys. If the aim is to broadly capture all biota then multiple substrates will be required. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
34. Slow Time: Nyaparu (William) Gardiner and the Strike Camps of the Pilbara.
- Author
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Jorgensen, Darren
- Subjects
MIGRANT labor ,STRIKES & lockouts ,INDIGENOUS peoples ,WAITING rooms ,CAMPS ,ART history - Abstract
Nyaparu (William) Gardiner's drawings and paintings bring a lived perspective to histories of the 1946 pastoral workers' strike in the Pilbara in Western Australia. This strike has been documented largely through the dramatic events of 1946 and through the subsequent struggles of strike leaders, including Clancy McKenna and Don McLeod, with the state government. Gardiner was born into the strike, and worked on its mining and pastoral settlements before leaving to take up station work elsewhere. His drawings and paintings document the "slow time" of strike life, of everyday labour and waiting, of his fellow workers on the strike camps, as well as his subsequent work with cattle and horses in the North West. Only beginning to make art in the last years of his life, Gardiner created his portraits of strike leaders, workers and landscapes from memory, and they contain a ghostly quality as they recall an era and many people who have died. His pictures testify to an impoverished autonomy for Aboriginal people and itinerant workers in the North West in the 1950s and 1960s. They offer a history from below, to supplement the political histories of the strike and its aftermath in this region of Australia. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
35. Albinism in Dasyurus species – a collation of historical and modern records.
- Author
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Dunlop, Judy, Peacock, David, Moore, Harry, and Cowan, Mitchell
- Subjects
ALBINISM ,DNA analysis ,SPECIES ,RECORDS ,MARSUPIALS - Abstract
A new record of an albino marsupial, the northern quoll (Dasyurus hallucatus), is described and placed in the context of 10 records since 1874 from all four Australian quoll species. Of the 10 previous records, one was D. hallucatus , seven are likely to be D. viverrinus , one D. maculatus and one unknown. The recent record comprises the live capture of a healthy adult female northern quoll from the Pilbara region of Western Australia. Despite the rarity and likely deleterious nature of the albino condition, this animal appeared to be in good health, carrying eight pouch young, and was released at location of capture following tissue sampling for DNA analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
36. Blind scolopendrid centipedes of the genus Cormocephalus from subterranean habitats in Western Australia (Myriapoda: Scolopendromorpha: Scolopendridae).
- Author
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Edgecombe, Gregory D., Huey, Joel A., Humphreys, William F., Hillyer, Mia, Burger, Mieke A., Volschenk, Erich S., and Waldock, Julianne M.
- Subjects
MYRIAPODA ,CENTIPEDES ,PLANT morphology ,MOLECULAR phylogeny ,ARID regions ,HABITATS - Abstract
Only a single blind species is known in the centipede family Scolopendridae, representing the monotypic genus Tonkinodentus Schileyko, 1992, from Vietnam. All of more than 400 other species have four ocelli on each side of the cephalic plate. A complex of three new blind species of the genus Cormocephalus Newport, 1844, is described from the subterranean fauna of the central Pilbara region of Western Australia. Phylogenies based on sequence data for the barcode region of COI and a concatenated matrix that also includes 12S rRNA, 28S rRNA and ITS2 unite the blind Pilbara species as a monophyletic group, albeit with moderate bootstrap support, informally named the C. sagmus species group. Cormocephalus sagmus , C. pyropygus and C. delta spp. nov. supplement 17 epigean congeners previously described from Australia. The new species are all morphologically similar, but can be distinguished using the shape and spinulation of the ultimate leg prefemur. Two additional genetically distinct lineages were recovered that are not described, owing to the specimens being immature or lacking diagnostic morphological characters. The subterranean radiation in the Pilbara is more closely related to species from forests in the south-west of Western Australia than to congeners from the arid zone. http://zoobank.org/urn:lsid:zoobank.org:pub:6F67FD31-A373-4DC5-A5FD-374D32DEE02C Only 1 of 400 known species of scolopendrid centipedes worldwide is blind. A radiation of blind species of this group occurs in the Pilbara region of Western Australia, being restricted to subterranean habitats. Molecular phylogeny based on three genes permits the relationships of three formally named new species and two unnamed species of blind Cormocephalus to be inferred. The blind arid-zone species are more closely related to congeners from forests in the south-west of Western Australia than to geographically closer species from the arid zone. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
37. Earliest life on Earth: Evidence from the Barberton Greenstone Belt, South Africa.
- Author
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Homann, Martin
- Subjects
- *
GREENSTONE belts , *FOSSIL microorganisms , *MICROBIAL mats , *TRACE fossils , *SEDIMENTARY rocks , *HYDROTHERMAL vents , *MICROBIAL communities - Abstract
Studies investigating the structure and diversity of Earth's record of life older than 3.2 Ga are restricted to two locations worldwide in which sedimentary rocks have escaped regional high-grade metamorphism and penetrative deformation: the Pilbara Craton of Western Australia and the Barberton Greenstone Belt in the Kaapvaal Craton of South Africa. This paper provides a South African perspective on the evidence of Paleoarchean life; a record that is often overlooked in the literature. It aims to summarize and critically review previously reported claims of early life in the BGB, gives an overview of the latest findings, and provides an outlook on potential future discoveries. The ~15 km thick, volcanic-sedimentary succession making up the Barberton Supergroup was deposited between 3.55 to ca. 3.20 Ga and can be subdivided in three stratigraphic units that provide a unique window into a diverse and widespread Paleoarchean microbial ecosystem landscape. Putative biosignatures occur almost throughout the entire BGB stratigraphy and range from carbonaceous cherts containing filamentous, spheroidal, and lenticular microstructures, traces of hydrothermal biofilms, photosynthetic microbial mats, remnants of pseudocolumnar stromatolites, and large, organic-walled spheroidal microfossils of currently unknown affinity. The BGB also contains one of the world's oldest known record of tufted microbial mats, which extensively colonized tidally-influenced, siliciclastic shorelines and were most likely formed by filamentous photosynthesizers. Other mat-associated biosignatures include silicified gas bubbles, domes and lenses that likely formed due to metabolic activity or the decay of buried organic matter. Some of these subsurface voids beneath the cohesive mats were inhabited by the earliest known forms of cavity-dwelling microbial communities that were probably dominated by chemotrophic or photosynthetic microbes. Recently discovered terrestrial microbial mats, once thriving in a fluvial-dominated setting, represent the oldest macroscopically-visible fossil traces of life on land, which is also supported by the occurrence of nearby paleosols that carry signals of biogenic sulfur fractionation. The wealth of preserved microbial biosignatures from marine, fluvial, hydrothermal, and possibly planktonic settings combined with the high spatial and temporal resolution of the Barberton Greenstone Belt deposits is truly exceptional, Consequently, the BGB deserves an equal level of attention and protection for future generations like its Australian counterpart. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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38. New Bathynellidae (Crustacea) taxa and their relationships in the Fortescue catchment aquifers of the Pilbara region, Western Australia.
- Author
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Perina, Giulia, Camacho, Ana I., Huey, Joel, Horwitz, Pierre, and Koenders, Annette
- Subjects
WATERSHEDS ,CRUSTACEA ,POISSON processes ,NUCLEOTIDE sequence ,MINING corporations ,AQUIFERS - Abstract
In the past 20 years, the number of subterranean taxa discovered in Australia, especially in the Pilbara bioregion, has considerably increased due to incidental environmental surveys often associated with mining development. Bathynellidae are an important component of stygofauna and they occur in most Australian aquifers, but their collection and identification are difficult due to their habitat, and small and fragile bodies with conservative morphology. The study of Pilbaranella ethelensis in the upper Fortescue catchment contributed to a better understanding of the group at local scale, but knowledge at larger catchment scale is still limited. Abundant material collected by different environmental consultant companies on behalf of mining companies allowed an accurate analysis of the populations of Central Hamersley Range bathynellids. A new genus and one new species from the lower Fortescue catchment, Fortescuenella serenitatis gen. et sp. nov., is described using an approach that integrates morphological and molecular data. Three additional lineages are defined through morphology and DNA sequencing, using Automatic Barcode Gap Discovery and Poisson Tree Processes species delimitation methods. Based on previous knowledge on bathynellids and other stygofauna we expected to find multiple taxa, geographically restricted, possibly related to each other and to Pilbaranella genus described upstream of the Fortescue catchment. The phylogenetic reconstruction of the relationships among known lineages of the family in the Pilbara highlights a pattern of distribution characterized by a complex evolutionary history that does not reflect contemporary surface water catchments, suggesting a diversification that preceded the aridification processes started in the north of Western Australia during the Miocene. This study also clarifies the status of the 'cosmopolitan' Bathynella by excluding the Australian bathynellids from this genus. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
39. A low number of introduced marine species in the tropics: a case study from Singapore.
- Author
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Wells, Fred E., Koh Siang Tan, Todd, Peter A., Jaafar, Zeehan, and Yeo, Darren C. J.
- Subjects
INTRODUCED species ,BALLAST water ,MARINE ecology ,FISH stocking ,MARINE invertebrates - Abstract
Non-indigenous marine species (NIMS) are being transported around the world by anthropogenic mechanisms, particularly by vessels in ballast water or as biofouling. A small subset of NIMS become invasive marine species (IMS) and can cause considerable damage to local marine ecosystems. Understanding where NIMS originate, how they are transported, and their effects in the new environments are crucial to the management of IMS. As one of the busiest ports in the world that handles tens of thousands of high invasion-risk vessels annually, Singapore is regarded as being at very high risk for the introduction of NIMS and IMS. However, a compilation of 3,650 marine invertebrates, fishes and plants revealed that only 22 species have been confirmed as NIMS. The results are consistent with a growing dataset that suggests biodiverse marine ecosystems in the tropical Indo-West Pacific are less susceptible to introductions than previously thought. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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40. Strategies to breed sterile leucaena for Western Australia.
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REAL, DANIEL, YONG HAN, BAILEY, C. DONOVAN, VASAN, SAIPRIYAA, CHENGDAO LI, CASTELLO, MARIECLAIRE, BROUGHTON, SUE, ABAIR, ALEXANDER, CROUCH, SAM, and REVELL, CLINTON
- Subjects
PLANT breeding ,FORAGE plants ,VEGETATIVE propagation ,LEAD tree ,GENOME editing ,PLANT biotechnology - Abstract
Copyright of Tropical Grasslands / Forrajes Tropicales is the property of International Centre for Tropical Agriculture - CIAT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
41. Conspicuously concealed: revision of the arid clade of the Gehyra variegata (Gekkonidae) group in Western Australia using an integrative molecular and morphological approach, with the description of five cryptic species.
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Kealley, Luke, Doughty, Paul, Pepper, Mitzy, Keogh, J. Scott, Hillyer, Mia, and Huey, Joel
- Subjects
GECKOS ,ENDEMIC animals ,ARID regions ,GEOGRAPHIC boundaries ,SOUTHERN root-knot nematode ,SPECIES ,SEA level - Abstract
The methods used to detect and describe morphologically cryptic species have advanced in recent years, owing to the integrative nature of molecular and morphological techniques required to elucidate them. Here we integrate recent phylogenomic work that sequenced many genes but few individuals, with new data from mtDNA and morphology from hundreds of gecko specimens of the Gehyra variegata group from the Australian arid zone. To better understand morphological and geographical boundaries among cryptic forms, we generated new sequences from 656 Gehyra individuals, largely assigned to G. variegata group members over a wide area in Western Australia, with especially dense sampling in the Pilbara region, and combined them with 566 Gehyra sequences from GenBank, resulting in a dataset of 1,222 specimens. Results indicated the existence of several cryptic species, from new species with diagnostic morphological characters, to cases when there were no useful characters to discriminate among genetically distinctive species. In addition, the cryptic species often showed counter-intuitive distributions, including broad sympatry among some forms and short range endemism in other cases. Two new species were on long branches in the phylogram and restricted to the northern Pilbara region: most records of the moderately sized G. incognita sp. nov. are near the coast with isolated inland records, whereas the small-bodied saxicoline G. unguiculata sp. nov. is only known from a small area in the extreme north of the Pilbara. Three new species were on shorter branches in the phylogram and allied to G. montium. The moderately sized G. crypta sp. nov. occurs in the western and southern Pilbara and extends south through the Murchison region; this species was distinctive genetically, but with wide overlap of characters with its sister species, G. montium. Accordingly, we provide a table of diagnostic nucleotides for this species as well as for all other species treated here. Two small-bodied species occur in isolated coastal regions: G. capensis sp. nov. is restricted to the North West Cape and G. ocellata sp. nov. occurs on Barrow Island and other neighbouring islands. The latter species showed evidence of introgression with the mtDNA of G. crypta sp. nov., possibly due to recent connectivity with the mainland owing to fluctuating sea levels. However, G. ocellata sp. nov. was more closely related to G. capensis sp. nov. in the phylogenomic data and in morphology. Our study illustrates the benefits of combining phylogenomic data with extensive screens of mtDNA to identify large numbers of individuals to the correct cryptic species. This approach was able to provide sufficient samples with which to assess morphological variation. Furthermore, determination of geographic distributions of the new cryptic species should greatly assist with identification in the field, demonstrating the utility of sampling large numbers of specimens across wide areas. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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42. Using Structure-from-Motion Photogrammetry to Improve Roughness Estimates for Headwater Dryland Streams in the Pilbara, Western Australia.
- Author
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Flatley, Alissa, Rutherfurd, Ian, and Sims, Alexander
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EPHEMERAL streams ,WATERSHEDS ,POINT cloud ,PHOTOGRAMMETRY ,MACHINE learning - Abstract
There are numerous situations where engineers and managers need to estimate flow resistance (roughness) in natural channels. Most estimates of roughness in small streams come from humid areas. Ephemeral streams in arid and semi-arid areas have different morphology and vegetation that leads to different roughness characteristics, but roughness in this class of stream has seldom been studied. A lack of high-resolution spatial data hinders our understanding of channel form and vegetation composition. High resolution structure-from-motion (SfM)-derived point clouds allow us to estimate channel boundary roughness and quantify the influence of vegetation during bankfull flows. These point clouds show individual plants at centimetre accuracy. Firstly, a semi-supervised machine learning procedure called CANUPO was used to identify and map key geomorphic features within a series of natural channels in the Pilbara region of Western Australia. Secondly, we described the variation within these reaches and the contribution of geomorphic forms and vegetation to the overall in-channel roughness. Channel types are divided into five reach types based on presence and absence of geomorphic forms: bedrock; alluvial single channel (≥cobble or sand dominated); alluvial multithread; composed of either nascent barforms or more established; stable alluvial islands. Using this reach classification as a guide, we present estimates of Manning's roughness within these channels drawing on an examination of 650 cross sections. The contribution of in-channel vegetation toward increasing channel roughness was investigated at bankfull flow conditions for a subset of reaches. Roughness within these channels is highly variable and established in-channel vegetation can provide between a 35–55% increase in total channel roughness across all channel types. This contribution is likely higher in shallow flows and identifies the importance of integrating vegetation and geomorphic features into restorative practices for these headwater channels. These results also guide Manning's selection for these semi-arid river systems and contribute to the vegetation-roughness literature within a relatively understudied region. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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43. A Hotspot of Arid Zone Subterranean Biodiversity: The Robe Valley in Western Australia.
- Author
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Clark, Huon L., Buzatto, Bruno A., and Halse, Stuart A.
- Subjects
ARID regions ,BOREHOLES ,GEOLOGIC hot spots ,ROBES ,BIODIVERSITY ,RIVER channels - Abstract
Knowledge of subterranean fauna has mostly been derived from caves and streambeds, which are relatively easily accessed. In contrast, subterranean fauna inhabiting regional groundwater aquifers or the vadose zone (between surface soil layers and the watertable) is difficult to sample. Here we provide species lists for a globally significant subterranean fauna hotspot in the Robe Valley of the Pilbara region, Western Australia. This fauna was collected from up to 50 m below ground level using mining exploration drill holes and monitoring wells. Altogether, 123 subterranean species were collected over a distance of 17 km, comprising 65 troglofauna and 58 stygofauna species. Of these, 61 species were troglobionts and 48 stygobionts. The troglofauna occurs in small voids and fissures in mesas comprised mostly of an iron ore formation, while the stygofauna occurs in the alluvium of a river floodplain. The richness of the Robe Valley is not a localized aberration, but rather reflects the richness of the arid Pilbara region. While legislation in Western Australia has recognized the importance of subterranean fauna, mining is occurring in the Robe Valley hotspot with conditions of environmental approval that are designed to ensure species persistence. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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44. Timing and development of sedimentation of the Cleaverville Formation and a post‐accretion pull‐apart system in the Cleaverville area, coastal Pilbara Terrane, Pilbara, Western Australia.
- Author
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Kiyokawa, Shoichi, Aihara, Yuhei, Takehara, Mami, and Horie, Kenji
- Subjects
BANDED iron formations ,STRIKE-slip faults (Geology) ,SHALE ,SEDIMENTATION & deposition - Abstract
Copyright of Island Arc is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
45. Concentrations of some metals in the nearshore marine sediments of Western Australia's Pilbara Region.
- Author
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Stoddart, James A., Welsh, Justin Q., and Stoddart, Christopher W.
- Subjects
MARINE sediments ,METALS ,CHROMIUM ,HEXAVALENT chromium ,SEDIMENTS ,ARSENIC - Abstract
Concentrations of arsenic, nickel and chromium in sediments of the nearshore Pilbara Region of Western Australia's mid -north coast have caused concerns to regulators issuing ocean disposal permits for many years. A meta-analysis of data from a large number of surveys, conducted in support of permit applications over many years and across hundreds of kilometres of coastline, shows that, when assessed as total metal concentrations, chromium and nickel occur routinely at concentrations above those recommended as screening triggers by national guidelines and arsenic more rarely. Arsenic was concentrated in surface sediments, consistent with an organic origin. Concentrations of nickel and chromium were higher in deeper sediment layers, consistent with a natural geological origin. However, sediment particle sizing was a major determinant of total metal concentrations of all three metals, and bioavailability was always much lower and within recommended guidelines. Past dredging activity for channels and berths in the large ports of the Pilbara has most likely led to an elevation of fine fractions of surface sediments within operating port areas, when compared to the undisturbed surrounding areas, and may also have increased the proportion of sediment from deeper substrates at the surface. Whilst total concentrations of chromium and nickel commonly exceed screening guidelines throughout the nearshore Pilbara Region, their bioavailability was low and these metals present a little threat to biota. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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