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171.
Folco Giacomini Vittorio Boerio Simona Polattini Massimo Tiepolo Riccardo Tribuzio Alberto Zanetti 《Environmental Earth Sciences》2010,61(8):1621-1639
This work is part of the project study for a road tunnel bypassing the town of Genova and was aimed at evaluating the amount of asbestos fibres in the metaophiolites belonging to the Voltri Group and the Sestri–Voltaggio Zone (Liguria, Northern Italy). The 85 studied rock samples (mainly mafic and ultramafic rocks) derive from exposed outcrops and prospecting boreholes. The study of field relations and petrographic/microtextural investigations under the optical microscope allowed for the identification and characterisation of asbestos-bearing settings and lithotypes. Mineralogy and concentration of asbestos fibres in powdered specimens were determined by means of a scanning electron microscope equipped with an energy-dispersive X-ray spectroscopy device. These investigations were combined with petrography on thin-section, X-ray diffraction analysis and phase contrast optical microscopy on rock powders. Mafic and ultramafic rocks commonly contain asbestos in concentrations below 1,000 mg/kg (considered as the contamination threshold under Italian law). However, the fibre concentration rises abruptly within localised zones, where the metaophiolite sequences were involved into late ductile to brittle tectono-metamorphic events. Two groups of asbestos-bearing settings have been so far identified in the area: (a) fracture networks within serpentinites (dominated by fibrous chrysotile), and (b) boudins of chlorite-tremolite schists, likely deriving from dynamic recrystallisation of mafic rocks under greenschist facies conditions (dominated by fibrous amphibole). Even considering the low volumetric incidence of these settings (metres to few tens of metres), their high asbestos content locally controls the total fibre amount in the excavation products, thus requiring special prevention measures during excavation, management and final storage of the contaminated debris. 相似文献
172.
Thomas Higham Fiona Brock Marco Peresani Alberto Broglio Rachel Wood Katerina Douka 《Quaternary Science Reviews》2009,28(13-14):1257-1267
Radiocarbon dating of material from Late Pleistocene archaeological sites is challenging. Small amounts of modern 14C-labelled contamination will significantly affect the reliability of dates from the period, producing erroneous results. Recent developments in sample pre-treatment chemistry have shown that problems in reliable age determination during this period are surmountable. In this paper we provide an example of one such case, from the Middle to Upper Palaeolithic transitional site of the Grotta di Fumane, in northern Italy. We AMS dated two fractions of the same charcoal samples derived from a series of superimposed Mousterian, Aurignacian and Gravettian levels excavated at the site. One fraction was treated using the routine acid–base–acid (ABA) method, the other with the more rigorous acid–base-oxidation/stepped combustion (ABOx–SC) method. The latter method produced consistently older, and almost certainly more reliable, results. The eruption of the known-age Campanian Ignimbrite from the Phlegrean Fields near present-day Naples at 39.3 ka yr BP seals Ulluzzian and Proto Aurignacian levels in the south of Italy. Equivalent cultural levels are present at Fumane and the results obtained with the ABOx–SC methods are consistent with the ages inferred for sites in the south of Italy based on the presence of the Campanian Ignimbrite. New results from a sample found beneath the Campanian Ignimbrite at the Russian site of Kostenki, obtained using both the ABA and ABOx–SC, methods are also presented. They support the conclusion reached at Fumane by demonstrating that, in many cases, the ABOX–SC treatment effectively removes contamination where the ABA treatment does not. The results of the work offer a sobering examination of the problems inherent in the current radiocarbon database relating to the period, and highlight the dangers of an uncritical use of the corpus of 14C results obtained over the last few decades. Based on our results, we predict that more than 70% of the 53 previously available determinations from Fumane are erroneously young. A way forward is suggested, using these improved chemical preparation methods, applying analytical methods to characterise the material dated, and testing existing site chronologies to establish which previous determinations are liable to be inaccurate. 相似文献
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Hilary McMillan Alberto Montanari Christophe Cudennec Hubert Savenije Heidi Kreibich Tobias Krueger 《水文科学杂志》2020,65(Z1):1174-1191
ABSTRACTIn 2013, the International Association of Hydrological Sciences (IAHS) launched the hydrological decade 2013–2022 with the theme “Panta Rhei: Change in Hydrology and Society”. The decade recognizes the urgency of hydrological research to understand and predict the interactions of society and water, to support sustainable water resource use under changing climatic and environmental conditions. This paper reports on the first Panta Rhei biennium 2013–2015, providing a comprehensive resource that describes the scope and direction of Panta Rhei. We bring together the knowledge of all the Panta Rhei working groups, to summarize the most pressing research questions and how the hydrological community is progressing towards those goals. We draw out interconnections between different strands of research, and reflect on the need to take a global view on hydrology in the current era of human impacts and environmental change. Finally, we look back to the six driving science questions identified at the outset of Panta Rhei, to quantify progress towards those aims.
Editor D. Koutsoyiannis; Associate editor not assigned 相似文献
175.
Serena Ceola Alberto Montanari Tobias Krueger Fiona Dyer Heidi Kreibich Ida Westerberg 《水文科学杂志》2020,65(Z1):2803-2817
ABSTRACTWe explore how to address the challenges of adaptation of water resources systems under changing conditions by supporting flexible, resilient and low-regret solutions, coupled with on-going monitoring and evaluation. This will require improved understanding of the linkages between biophysical and social aspects in order to better anticipate the possible future co-evolution of water systems and society. We also present a call to enhance the dialogue and foster the actions of governments, the international scientific community, research funding agencies and additional stakeholders in order to develop effective solutions to support water resources systems adaptation. Finally, we call the scientific community to a renewed and unified effort to deliver an innovative message to stakeholders. Water science is essential to resolve the water crisis, but the effectiveness of solutions depends, inter alia, on the capability of scientists to deliver a new, coherent and technical vision for the future development of water systems.
EDITOR D. Koutsoyiannis; ASSOCIATE EDITOR not assigned 相似文献
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Many applications are multivariate in character and call for stochastic images of the joint spatial variability of multiple variables conditioned by a prior model of covariances and cross- covariances. This paper presents an algorithm to perform cosimulation of such spatially intercorrelated variables. This new algorithm builds on a Markov-type hypothesis whereby collocated information screens further away data of the same type, allowing cosimulation without the burden of a full cokriging. The proposed algorithm is checked against a synthetic multi-Gaussian reference dataset, then against a multi-Gaussian cosimulation approach using full cokriging. The results indicate that the proposed algorithm perform as well as the full cokriging approach in reproducing the univariate and bivariate statistics of the reference set, yet at less cpu cost. 相似文献
180.
Dr. Alberto Marcos Dr. Maria L. Arboleya 《International Journal of Earth Sciences》1975,64(1):278-287
Examples of progressive deformation provided by minor structures are not frequent in the geological literature. In NW Spain some minor structures in Lower Paleozoic inhomogeneous layered material may be interpreted as the result of progressive deformation during the Hercynian Orogeny. The examples described include structures generated by progressive contraction (folded wedges), contraction followed by elongation (folds disrupted by boudinage) and elongation followed by contraction (folded boudins). 相似文献