1,720,961 research outputs found
Whole rock geochemistry, electron microprobe and laser ablation ICP-MS geochemistry of the Georgina Basin phosphorites
No full textThis dataset comprises whole rock geochemistry of the Georgina Basin (Queensland, northern Australia) phosphorites and their locations, along with the underlying basement rocks (Sybella Granites, Proterozoic Schists and McNamarra Group metasediments of the Lawn Hill Platform). Phosphorite samples were collected in 2020 by the Geological Survey of Queensland from drillholes provided by individual companies that hold the tenements over the analysed prospects (Ardmore, Phosphate Hill, Duchess, Lily Creek, Sherrin Creek, DTREE, Barr Creek, Paradise North and Paradise South). Basement rock sample were collected during a field campaign in June-July 2021. Whole rock geochemistry was obtained through external laboratory (ALS Global) using lithium borate fusion method, with full dataset published previously by authors (Valetich et al., 2022 - Chemical Geology, v.588, 120654). Laser ablation and microprobe geochemistry of the individual phosphate (carbonate fluorapatite) clasts (phosclasts and microcrystalline carbonate fluorapatite) was carried out at Adelaide Microscopy (The University of Adelaide) using the procedures detailed in the publication linked to this dataset in the Geochemistry, Geophysics, Geosystems (G Cubed) journal
Electron microprobe data of carbonate fluorapatite pellets from the Phosphate Hill phosphorite prospect in the Georgina Basin
No full textLaser ablation ICPMS trace element data of microcrystalline carbonate fluorapatite and individual peloids (phosclasts) of the granular phosphorites from the Georgina Basin phosphorite prospects
No full textSample locations and whole rock geochemistry for phosphorite samples from the Cambrian Georgina Basin
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Chalcophile Evolution in Arc Magmas: The Story of Boninites
Get PDFBoninites are magmas derived by partial melting of highly refractory (prior melt-depleted) mantle sources. Their high-MgO at intermediate silica contents are generally restricted to supra-subduction zone, mantle wedge settings. A comprehensive study of silicate glass (formerly melt) inclusions (MI), volcanic groundmass glasses, and sulfide inclusions in boninites from the Bonin (Ogasawara) Ridge has been undertaken to constrain the behaviour of trace elements, with a particular focus on chalcophile element (Cu, Ag, PGE) abundances in these types of melt. An emphasis on high-resolution, in situ analyses has shed light on processes that control chalcophile element behaviour including, but not exclusively sulfide saturation. A broad compositional array of boninite series melts were characterised and compared to existing datasets of both in-situ glass (groundmass glass and MI), and whole rock analyses. Direct comparison between bulk and in situ datasets in the literature has revealed erroneous conclusions regarding the petrogenesis of different parental boninite melts along the Ogasawara Ridge. An alternative classification method is presented here, utilising trace elements rather than major elements, and an unsupervised machine learning algorithm to classify boninite series glasses in high dimension geochemical space. The results show that the most fractionated boninite series melts preserve geochemical fingerprints of their parentage. In conjunction with the comprehensive trace element dataset, Fe K-edge XANES of MI are presented. Fe-XANES of MI show the first direct evidence that parental boninites are equally or more reduced than MORB and become oxidised during fractionation. This suggests that the oxidised nature of arc magmas may not be a parental trait, which is of profound significance to the speciation of S and therefore the behaviour of chalcophile elements. Sulfide saturation is considered the dominant process controlling chalcophile elements in magmas, however the formation of metallic nanoparticles is evident in boninites and influences the behaviour of Ag and PGE. The formation of nanoparticles is perhaps enhanced in boninites relative to other melts due to their reduced nature and lack of S. Understanding the processes that control chalcophile elements in evolving magmas is important for constraining models describing the genesis of magmatic ore deposits, for example porphyry Cu-Au (Mo, Ag, W) deposits. To complement the study of magmatic chalcophile evolution in boninites, an experimental study of magmatic volatile phase (MVP) saturation was undertaken. Previous studies have shown that major ore-forming components, Cl and S, decouple during staggered MVP saturation. However, the behaviour of chalcophile elements during these processes has not previously been characterized. Results from this study show that Cu and Cl decouple from S during MVP saturation, which has potentially far-reaching implications for our understanding of porphyry deposit formation
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