49 research outputs found

    Early Badenian transgression on the outer flank of Western Carpathian Foredeep, Hluchov area, Czech Republic

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    This multidisciplinary study, based on borehole cores from the Hluchov area in Czech Republic, docu- ments an early Badenian marine transgression on the outer flank of the Western Carpathian Foredeep . The shallow-marine deposits represent coastal transgression over a terrestrial topography of weathered pre-Cenozoic bedrock. The lower facies association (FA1) consists of siliciclastic sediment derived from local substrate erosion. Facies indicate a wave-dominated environment with unstable bottom, variable rate of sediment supply and an incremental rise of relative sea level. The upper facies association (FA2) consists of carbonates indicating a major landward shift of shoreline, decline in siliciclastic input and further sea-level rise. The succession represents a transgressive to highstand systems tract. The maximum flooding surface, ca . 1 m above the FA1/FA2 boundary, is signified by an anomalous decrease in K and Th, an increased Th/K ratio and highest U concentration. The heavy-mineral assemblages in FA1 confirm local sediment provenance, whereas those in FA2 indicate broader sediment derivation, including volcanic component from contemporaneous rhyolitic to rhyodacitic eruptions. The deposits contain a wide range of marine fauna, with the foraminifers and molluscs indicating an early Badenian age. Molluscs, bryozoans and echinoderms indicate a normal-salinity environment with a decreasing hydraulic energy. Foraminifers indicate salinity fluctua- tions in the lowest part of the succession. The isotopic composition of mollusc shells shows marked inter-species differences and a general negative shift in the d 13 C and d 18 O values, indicating diagenetic alteration. The impact of diagenetic processes appears to have been controlled by sedimentary facies. The highly negative d 13 C and d 18 O values correspond to sediment layers with the highest Th/K ratios and hence low clay content. Sediment permea- bility was thus probably crucial in controlling the differential circulation and impact of diagenetic fluids

    The mineralogical composition of calcium and calcium-magnesium carbonate pedofeatures of calcareous soils in the European prairie ecodivision in Hungary

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    Abstract There is little data on the mineralogy of carbonate pedofeatures in the calcareous soils in Hungary which belong to the European prairie ecodivision. The aim of the present study is to enrich these data. The mineralogical composition of the carbonate pedofeatures from characteristic profiles of the calcareous soils in Hungary was studied by X-ray diffractometry, thermal analysis, SEM combined with microanalysis, and stable isotope determination. Regarding carbonate minerals only aragonite, calcite (+ magnesian calcite) and dolomite (+proto-dolomite) were identified in carbonate grains, skeletons and pedofeatures. The values relating, respectively, to stable isotope compositions (C13, O18) of carbonates in chernozems and in salt-affected soils were in the same range as those for recent soils (latter data reported earlier). There were no considerable differences between the values for the carbonate nodules and tubules from the same horizons, nor were there significant variations between the values of the same pedofeatures from different horizons (BC-C) of the same profile. Thus it can be assumed that there were no considerable changes in conditions of formation. Tendencies were recognized in the changes of (i) carbonate mineral associations, (ii) the MgCO3 content of calcites, (iii) the corrected decomposition temperatures, and (iv) the activation energies of carbonate thermal decompositions among the various substance-regimes of soils. Differences were found in substance-regimes types of soils rather than in soil types

    Moving from contractor to owner operator: Impact on safety culture; a case study

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    Purpose – The purpose of this paper is to investigate whether a change in staffing contractual arrangements, specific training in hazard identification, mentoring of supervisors and the introduction of a robust safety system could improve an organisation\u27s safety culture. How safety conditions change under contracted out labour compared to direct labour and the influence that contracting out has on organisational safety culture is explored. Design/methodology/approach – The study used a case study methodology to detail how the change occurred over a six month period in 2011. As part of the analysis a model of the change process and push-pull factors is offered. Findings – As a result of the change, all areas saw some improvement. Work-related injury statistics dropped significantly, supervisors were clear of their roles, actively monitoring their crews to ensure they worked in a safer manner than before, and staff were actively addressing work-place hazards. With the safety system in place the organisation should be deemed compliant and diligent by the state auditing authorities. This study has also shown that using contractor workers together with in-house workers that are managed under different safety regimes is problematic. The problems don’t occur due to the contractor\u27s safety systems being less robust than the parent company\u27s or that contract workers are themselves less safe; it is the added complexity of managing multiple safety regimes and the lack of trust of the robustness of each system that create conflict. Research limitations/implications – The paper reports on the change process of one mining organisation in Western Australia as a case study from a managerial sample and is thereby limited. Practical implications – This study demonstrates the difficulties in changing safety culture in an underground mining organisation. The paper argues the need for specialised training in identifying hazards by the staff, the mentoring of supervisory staff and the adoption of a robust safety system to support improved safety culture. Originality/value – There is little research conducted in the resources sector researching changes in human resource supply and OHS management, in particular moving from contracted labour to hiring in-house. This case provides an insight into how a change in staffing hiring arrangements, together with specific safety initiatives, has a positive impact on safety performance

    Carbon isotope excursions and microfacies changes in marine Permian-Triassic boundary sections in Hungary

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    Several Permian-Triassic boundary sections occur in various structural units within Hungary. These sections represent different facies zones of the western Palaeotethys margin. The Gardony core in the NE part of the Transdanubian Range typically represents the inner ramp, while the Balvany section in the Bukk Mountains of northern Hungary represents an outer ramp setting. The two sections have different patterns for their delta(13)C values. The Balvany section shows a continuous change towards more negative delta(13)C values starting at the first biotic decline, followed by a sharp, quasi-symmetric negative peak at the second decline. The appearance of the delta(13)C peak has no relationship to the lithology and occurs within a shale with low overall carbonate content, indicating that the peak is not related to diagenesis or other secondary influences. Instead, the shift and the peak reflect primary processes related to changes in environmental conditions. The continuous shift in delta(13)C values is most probably related to a decrease in bioproductivity, whereas the sharp peak can be attributed to an addition of C strongly depleted in (13)C to the ocean-atmosphere system. The most plausible model is a massive release of methane-hydrate. The quasi-symmetric pattern suggests a rapid warming-cooling cycle or physical unroofing of sediments through slope-failure and releasing methane-hydrate. The Gidony-1 core shows a continuous negative delta(13)C shift starting below the P-T boundary. However, the detailed analyses revealed a sharp delta(13)C peak in the boundary interval, just below the major biotic decline, although its magnitude doesn't reach that observed in the Balvany section. Based on careful textural examination and high-resolution stable isotope microanalyses we suggest that the suppression of the delta(13)C peak that is common in the oolitic boundary sections is due to combined effects of condensed sedimentation, sediment reworking and erosion, as well as perhaps diagenesis. (c) 2005 Elsevier B.V All rights reserved
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