377 research outputs found
Last interglacial (MIS 5e) sea-level determined from a tectonically stable, far-field location, Eyre Peninsula, southern Australia
The last interglacial maximum (Marine Isotope Substage 5e [MIS 5e], 128Âż116 ka) is a distinctive event in recent Earth history. Shoreline successions of this age are important for calibrating climate models and defining the overall behaviour of the crustÂżmantle system to fluctuating ice and ocean-water volumes. In a global context, the recently intensified interest in last interglacial shoreline successions has revealed considerable variability in the magnitude of sea-level rise during this time interval and highlighted the need to examine paleosea-level evidence from tectonically stable, far-field settings. Situated in the far-field of continental ice sheets and on the tectonically stable Gawler Craton, the 300 km coastal sector of western Eyre Peninsula between Fowlers Bay and Lake Newland in southern Australia represents an important region for defining the glacio-eustatic (ice-equivalent) sea-level attained during the last interglacial maximum based on the relative sea-level observations from this region. Low-energy, shoaling upward, peritidal bioclastic carbonate successions of the last interglacial (locally termed Glanville Formation) formed within back-barrier, estuarineÂżlagoonal environments in the lee of eolianite barrier complexes (locally termed Bridgewater Formation) along this coastline. The well-preserved shelly successions (coquinas) contain diverse molluscan fossil assemblages including species no longer living in the coastal waters of South Australia (e.g. the Sydney cockle Anadara trapezia and the benthic foraminifer Marginopora vertebralis). The extent of amino acid racemisation (a measure of fossil age based on increasing d/l value) in a range of species, and in particular A. trapezia and Katelysia sp., confirms the time equivalence of the isolated embayment-fill successions, correlated with the informal type section of the Glanville Formation at Dry Creek, north of Adelaide. Preliminary U-series analyses on A. trapezia also suggest a correlation with the last interglacial maximum, but further highlight the complexity in dating fossil molluscs by the U-series method in view of their open-system behaviour. The shelly successions of the Glanville Formation occur at elevations higher than attained by sea-level in the current, Holocene interglacial. A higher sea-level of between 2.1 Âą 0.5 and 4 Âą 0.5 m above present sea-level is inferred for the last interglacial maximum (MIS 5e) along this coastline based on the elevation of sedimentary successions host to the shallow subtidalÂżintertidal fossil molluscs Katelysia sp., and Anadara trapezia. The paleosea-level observations place a lower limit on the sea-level attained during the last interglacial maximum and suggest that caution be exercised in the definition of the upper limit of sea-level during this interglacial
Mapping of bioavailable strontium isotope ratios in France for archaeological provenance studies
Strontium isotope ratios (â¸âˇSr/â¸âśSr) of archaeological samples (teeth and bones) can be used to track mobility and migration across geologically distinct landscapes. However, traditional interpolation algorithms and classification approaches used to generate Sr isoscapes are often limited in predicting multiscale â¸âˇSr/â¸âśSr patterning. Here we investigate the suitability of plant samples and soil leachates from the IRHUM database (www.irhumdatabase.com) to create a bioavailable â¸âˇSr/â¸âśSr map using a novel geostatistical framework. First, we generated an â¸âˇSr/â¸âśSr map by classifying â¸âˇSr/â¸âśSr values into five geologically-representative isotope groups using cluster analysis. The isotope groups were then used as a covariate in kriging to integrate prior geological knowledge of Sr cycling with the information contained in the bioavailable dataset and enhance â¸âˇSr/â¸âśSr predictions. Our approach couples the strengths of classification and geostatistical methods to generate more accurate â¸âˇSr/â¸âśSr predictions (Root Mean Squared ErrorâŻ=âŻ0.0029) with an estimate of spatial uncertainty based on lithology and sample density. This bioavailable Sr isoscape is applicable for provenance studies in France, and the method is transferable to other areas with high sampling density. While our method is a step forward in generating accurate â¸âˇSr/â¸âśSr isoscapes, the remaining uncertainty also demonstrates that fine-modelling of â¸âˇSr/â¸âśSr variability is challenging and requires more than geological maps for accurately predicting â¸âˇSr/â¸âśSr variations across the landscape. Future efforts should focus on increasing sampling density and developing predictive models to further quantify and predict the processes that lead to â¸âˇSr/â¸âśSr variability.Funding was provided by ARC
DP110101415 (Grßn, Spriggs, Armstrong, Maureille and Falguères)
Understanding the migrations of prehistoric populations through direct
dating and isotopic tracking of their mobility patterns. Part of this research
was supported by the Australian French Association for Science &
Technology through the ACT Science Fellowship program (2013) to M.
Willme
"Poof! a'm heppily saving the Lord...": multimodality and evaluative discourses in male toilet graffiti at the University of the Western Cape
This paper explores the use of punctuation, capitalisation, linguistic forms and
images in the construction of evaluative discourses in male toilet graffiti at the
University of the Western Cape. Of particular interest is how male students use
these devises in the discursive construction of the appraisal resource of Attitude,
Graduation and Evaluation. Using over 150 tokens of graffiti, the paper uses a multimodal
approach employing notions of resemiotisation and remediation to show
how taboo language, font size, images and sketches are repurposed to aid the evaluation
of the 'self' and the 'other' in toilet graffiti. The paper shows that through utilising
multimodal texts, graffiti writers are able to reformulate and situate novel
meanings in contexts; and in terms of appraisal, the verbal and non-verbal semiotic
material are strategically combined to engender novel evaluations
Positive self-evaluation versus negative other-evaluation in the political genre of pre-election debates.
The present study explores the language of evaluation in a sub-genre of political discourse, pre-electoral debates, and its potential persuasive function for gaining voters via a contraposition of positive self-evaluation and negative evaluation of the other candidate. A further aim of this research is to check whether the candidateÂżs ideology has a bearing on the entities that get evaluated. After a brief examination of the characteristics of the sub-genre at hand, specifically in the Spanish context, we present the results of an evaluation analysis carried out in a corpus of 19,849 words, which is the extension of the most recent pre-electoral debate held in Spain between the candidates of the two main political parties. Taking into account Van DijkÂżs CDA framework (2005) for parliamentary debates as global semantic strategies of positive self-presentation and negative other-presentation, Martin and WhiteÂżs (2005) method was adopted as an analytical tool. The results showed that, although each candidate had different preferences in the choice of evaluative devices, they both used them as a strategy to win electoral votes while deprecating the opposing party and, therefore, minimizing their chances of winning the elections. On the other hand, and despite their opposing ideology, they both seem to defend those policies that are more widely accepted in order not to risk losing voters: public services and egalitarian social policies
Mapping of bioavailable strontium isotope ratios in France for archaeological provenance studies
Š 2017 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/
This author accepted manuscript is made available following 24 month embargo from date of publication (Dec 2017) in accordance with the publisherâs archiving policyStrontium isotope ratios (87Sr/86Sr) of archaeological samples (teeth and bones) can be used to track mobility and migration across geologically distinct landscapes. However, traditional interpolation algorithms and classification approaches used to generate Sr isoscapes are often limited in predicting multiscale 87Sr/86Sr patterning. Here we investigate the suitability of plant samples and soil leachates from the IRHUM database (www.irhumdatabase.com) to create a bioavailable 87Sr/86Sr map using a novel geostatistical framework. First, we generated an 87Sr/86Sr map by classifying 87Sr/86Sr values into five geologically-representative isotope groups using cluster analysis. The isotope groups were then used as a covariate in kriging to integrate prior geological knowledge of Sr cycling with the information contained in the bioavailable dataset and enhance 87Sr/86Sr predictions. Our approach couples the strengths of classification and geostatistical methods to generate more accurate 87Sr/86Sr predictions (Root Mean Squared ErrorâŻ=âŻ0.0029) with an estimate of spatial uncertainty based on lithology and sample density. This bioavailable Sr isoscape is applicable for provenance studies in France, and the method is transferable to other areas with high sampling density. While our method is a step forward in generating accurate 87Sr/86Sr isoscapes, the remaining uncertainty also demonstrates that fine-modelling of 87Sr/86Sr variability is challenging and requires more than geological maps for accurately predicting 87Sr/86Sr variations across the landscape. Future efforts should focus on increasing sampling density and developing predictive models to further quantify and predict the processes that lead to 87Sr/86Sr variability
Power and knowledge-building in teacher inquiry: negotiating interpersonal and ideational difference
Professional collaboration in schools features prominently in contemporary approaches to educational change. Advocates highlight the importance of situated knowledge to continuous teacher learning, sustained school reform and improved student learning. Critics portray collaboration as an invisible and coercive means of official control. The framework presented in this paper aims to treat these perspectives not as ideological positions but as starting points for empirical investigation into the dynamics of power in professional collaboration. The framework draws on social semiotic theories of language and functional linguistics to portray the ways in which the development of ideas and the development of social relations ideational and interpersonal meaning move in concert. Excerpts from an in-depth study of interaction among science teachers and teacher-leaders in a secondary school undergoing broad reform illustrate the application of this framework. Attention to the dynamics of support and challenge in the most generative of these interactions reveals distinctive patterns of the negotiation of interpersonal and ideational meaning. These patterns of control provide a means of connecting the microprocesses of building knowledge with the broader dynamics of power at play in educational change
Assessing social responsibility::A quantitative analysis of Appraisal in BPâs and IKEAâs social reports
A growing public awareness of the potential negative impacts of corporate activities on the natural environment and society compels large companies to invest increasing resources in the communication of their responsible conduct. This article employs Appraisal theory in a comparative analysis of BPâs and IKEAâs 2009 social reports, each companyâs record of their non-financial performance. The main objective is to explore how, through Appraisal resources, BP and IKEA construct their corporate identity and relationship with their stakeholders. The analysis reveals two markedly different approaches to the construction of a responsible corporate identity. While BP deploys interpersonal resources to portray itself as a trustworthy and authoritative expert, IKEA discloses itself as a sensitive and caring corporation, engaged in a continual effort to improve. These differences are interpreted in light of the legitimization challenges the two companies face
Connected parents: combining online and off-line parenthood in vlogs and blogs
This article explores evaluative discourse in a corpus sample of parents' vlogs (video
blogs) and blogs (henceforth v/ blogs) dealing with family tasks and responsibilities, as a reflection of underlying values concerning parenthood. It pays special attention to the important role played by the expression of attitude, understood as "ways of feeling" and
including the meanings of affect, judgement and appreciation, together with positive
politeness in the social practices of the discursive construction of online and off-line parenthood. Analysis and description of the data show two main patterns in parents' practices, either aiming at perfection through juggling and multi-tasking or building resistance to the demands of families and society. Results show that parents frequently exploit the system of affect for building positive face and rapport, while indirectly expressing judgement of social esteem and social sanction, which construct their identities as mothers and fathers and those of the members of their communities of practice. The corpus for the study consists of a random sample of 400 evaluative units in
posts and comments on v/ blogs dealing with family tasks and responsibilities (200 in English and 200 in Spanish, with half the sample being drawn from fathers' and the other half from mothers' v/ blogs). I will approach the analysis of the data from appraisal (Martin and White 2005, Bednarek 2008) and politeness theory (Brown and Levinson 1987) in order to explore the features of evaluative discourse and the management of face. The methodology for processing the data borrows quantitative techniques from Corpus Linguistics, including the coding and statistical treatment of the sample with UAM Corpus Tools (O'Donnell 2011), together with Pragmatics and Discourse Analysis (DA), as done in some previous research (SantamarĂa-GarcĂa 2011, 2014).Project "EMO-FUNDETT: EMOtion and language at work", I+D FFI2013-47792-C2-1-P, sponsored by the Spanish Ministry of Science and Innovatio
On Being Negative
This paper investigates the pragmatic expressions of negative evaluation (negativity) in two corpora: (i) comments posted online in response to newspaper opinion articles; and (ii) online reviews of movies, books and consumer products. We propose a taxonomy of linguistic resources that are deployed in the expression of negativity, with two broad groups at the top level of the taxonomy: resources from the lexicogrammar or from discourse semantics. We propose that rhetorical figures can be considered part of the discourse semantic resources used in the expression of negativity. Using our taxonomy as starting point, we carry out a corpus analysis, and focus on three phenomena: adverb + adjective combinations; rhetorical questions; and rhetorical figures. Although the analysis in this paper is corpus-assisted rather than corpus-driven, the final goal of our research is to make it quantitative, in extracting patterns and resources that can be detected automatically
The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia
Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35â50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the â20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546Âą12 ka (sdÂą5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/â17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted
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