U-Pb Saturn: New U-Pb/Pb-Pb Data Reduction Software for LA-ICP-MS

U-Pb Saturn is new freeware for U-Pb LA-ICP-MS data reduction. It has been developed to provide easy interaction with and visualisation of LA-ICP-MS U-Pb datasets, and allows fast and reliable data reduction of hundreds of data-points. Saturn offers dynamic graphic interfaces to quickly view, evaluate, and plot U-Pb and Pb-Pb isotope data. It operates online (or offline), giving the freedom to change parameters and reprocess data at any stage of data acquisition. The main interface allows the user to: (1) choose the best statistics for drift correction, (2) include/exclude offset factors and (3) apply (or not) Pb_c corrections in different modes. Signal intensities are displayed in a separate graphic interface that allows users to interact with the time-resolved signal of individual spot analyses. All graphic windows are interactive; any modification to data treatment (e.g., inclusion or exclusion of analyses of reference material, or modification of the time-resolved signal windows) is instantaneously updated on the data tables. Saturn is particularly attractive for beginners in LA-ICP-MS U-Pb geochronology as it is non-commercial, easy to install, and very interactive. Coding information and a version of the software can be accessed at http://www.air.ufop.br .     

Modeling Geospatial Uncertainty of Geometallurgical Variables with Bayesian Models and Hilbert–Kriging

Mathematical Geosciences - In mine planning, geospatial estimates of variables such as comminution indexes and metallurgical recovery are extremely important to locate blocks for which the energy...     

Phase equilibria in the KFeS<Subscript>2</Subscript>–Fe–S system at 300–600 °C and bartonite stability

The article deals with phase relations in the KFeS₂–Fe–S system studied by the dry synthesis method in the range of 300–600 °C and at a pressure of 1 bar. At the temperature below 513?±?3 °C, pyrite coexists with rasvumite and there are pyrite–rasvumite–KFeS₂ and pyrite–rasvumite–pyrrhotite equilibria established. Above 513?±?3 °C pyrite and rasvumite react to form KFeS₂ and pyrrhotite, limiting the pyrite–rasvumite association to temperatures below this in nature. The experiments also outline the compositional stability range of the copper-free analog of murunskite (K _x Fe_2?yS₂) and suggest that mineral called bartonite is not stable in the Cl-free system, at least at atmospheric pressure and the temperature in the experiments. Chlorbartonite could be easily produced after adding KCl in the experiment. Possible parageneses in the quaternary K–Fe–S–Cl system were described based on the data obtained in this research and found in the previous studies. The factors affecting the formation of potassium–iron sulfides in nature were discussed.     

Towards sustainable urban development: the social acceptability of high-rise buildings in a Ghanaian city

Over the years, many city managers, policy makers and academics alike have turned to high-rise buildings as pathway to sustainable urban development. However, the sustainability of such types of development in various geographical contexts, especially in sub-Saharan Africa, is a subject less explored. Amidst the promotion of high-rise development in a rapidly urbanizing metropolis in Ghana, Kumasi, the research empirically examined the social acceptability of high-rise residential facilities and the institutional capacity for their effective management. By conducting face-to-face interviews with sampled households, and critical public service providers in the metropolis, the study uncovered that, contrary to the evidence from many Asian cities, there is generally low social acceptability of high-rise developments, and a weak institutional capacity for effective service delivery. The research concludes that, whilst it is tempting to embrace high-rise buildings as sustainable development pathway, it is crucial they are pursued with much circumspection. In addition to their design being tailored to the local needs of the people for whom they are built, the promotion of high-rise development should recognize the importance of effective service delivery, and general social acceptability.     

Collins Glacier Retreat Process and Regional Climatic Variations,King George Island,Antarctica

This paper investigates the recent climatic variability and changes in snow line and ice front position in Collins Glacier, King George Island, South Shetland Islands, Antarctic Peninsula. This region has recorded one of the largest temperature increases in the past fifty years and has been demonstrated to be highly sensitive to climate changes. To monitor recent changes (1983–2006), we determined the fluctuations of the terminus and snow line of the glacier via remote sensing data and field observation in the summer of 2013. We conclude that the Collins Glacier has responded slowly to regional climate changes (decades or even centuries), as glacial responses to climatic events do not depend solely on one environmental variable. The glacier presented more retreat and elevation of the snow line in the north sector. The retreat data are correlated with the mean monthly temperature and annual number of days of melting‐degree variations.     

Geochemistry and palaeotectonic setting of amphibolites from the Western Tatra Mountains,southern Poland

Amphibolites from the crystalline basement of the Western Tatra Mountains, which are found as small lenses within migmatitic gneisses and mica schists, were formed during pre‐ or early Variscan amphibolite‐facies metamorphic events, and subsequently intruded by the post‐metamorphic Variscan Tatra Granite. The amphibolites occur in both the upper and lower metamorphic complexes, which are separated by a major subhorizontal shear zone in the Western Tatra Mountains. The amphibolites can be divided into three types: massive, striped and garnetiferous. The striped and massive amphibolites, concordant with a dominant S₁ foliation, and the garnet amphibolites, which cross‐cut the S₁ banding in the gneisses, were all originally intrusive dolerites. The striped amphibolites (consisting primarily of hornblende, andesine and quartz), and later, cross‐cutting garnet‐hornblende‐andesine‐quartz‐bearing amphibolites, predominate in the lower part of the dominantly migmatitic upper complex, and are exposed mainly on the ridges. The massive amphibolites, which contain a similar mineral assemblage, mainly occur in the usual unmigmatized lower structural unit. Chemical studies indicate that three amphibolite suites are present, which probably originated as a series of enriched tholeiites, similar to more recent plume‐influenced magmas, which were derived by partial melting of a spinel lherzolite with primitive mantle composition and compositionally slightly modified by crustal contamination. The amphibolites were intruded as dolerites into clastic sediments which had accumulated in an extensional basin floored by attenuated continental crust, a situation similar to that of amphibolites found in metamorphic complexes within the Variscan belt, e.g. in the Orlica–Snieznik area of the Sudetes, where amphibolites chemically similar to those in the Western Tatra also occur. Copyright © 2000 John Wiley & Sons, Ltd.     

Development of a drought vulnerability index using MCDM and GIS: study case in São Paulo and Ceará, Brazil

Natural Hazards - Although climate change vulnerability research in general has increased over the last decade, Latin American countries have more directed more limited efforts toward vulnerability...     

Effect of cumulative seismic damage and corrosion on the life‐cycle cost of reinforced concrete bridges

Bridge design should take into account not only safety and functionality, but also the cost effectiveness of investments throughout a bridge life‐cycle. This paper presents a probabilistic approach to compute the life‐cycle cost (LCC) of corroding reinforced concrete (RC) bridges in earthquake‐prone regions. The approach is developed by combining cumulative seismic damage and damage associated with corrosion due to environmental conditions. Cumulative seismic damage is obtained from a low‐cycle fatigue analysis. Chloride‐induced corrosion of steel reinforcement is computed based on Fick's second law of diffusion. The proposed methodology accounts for the uncertainties in the ground motion parameters, the distance from the source, the seismic demand on the bridge, and the corrosion initiation time. The statistics of the accumulated damage and the cost of repairs throughout the bridge life‐cycle are obtained by Monte‐Carlo simulation. As an illustration of the proposed approach, the effects of design parameters on the LCC of an example RC bridge are studied. The results are valuable in better estimating the condition of existing bridges and, therefore, can help to schedule inspection and maintenance programs. In addition, by taking into consideration the two deterioration processes over a bridge life‐cycle, it is possible to estimate the optimal design parameters by minimizing, for example, the expected cost throughout the life of the structure. A comparison between the effects of the two deterioration processes shows that, in seismic regions, the cumulative seismic damage affects the reliability of bridges over time more than the corrosion even for corrosive environments. Copyright © 2008 John Wiley & Sons, Ltd.