348 research outputs found

    26Al-26Mg and stable isotopes investigated in ureilites

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    第6回極域科学シンポジウム[OA] 南極隕石11月17日(火) 国立国語研究所 2階 講

    Geochemical evidence (C, N and Pb isotopes) of recent anthropogenic impact in south-central Chile from two environmentally distinct lake sediment records

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Journal of Quaternary Science 25 (2010): 1100-1112, doi:10.1002/jqs.1364.In this paper, we compare the elemental and isotopic (C, N, Pb) geochemistry of lake sediments from two contrasted environments in South-Central Chile. The first lake, Laguna Chica de San Pedro (LCSP), is situated in the urbanized area of the Biobio Region (36°S). The second lake, Lago Puyehue (40°S), is located 400 km to the southeast of LCSP and belongs to an Andean national park. Our aim is to identify environmental impacts associated with increasing industrial activities and land-degradation during the last 150 years. In LCSP, shifts in C/N atomic ratios, δ13C and δ15N from 1915–1937 to the late 80’s are attributed to successive land-degradation episodes in the lake watershed. Based on a Pb isotopic mixing model, we estimate that up to 20% of lead in LCSP sediments is supplied from urban atmospheric pollution. By contrast, human impact in the watershed of Lago Puyehue is very limited. We observe no change in organic geochemistry during the last 150 years and lead contamination remains lower than 5%, even during the last decades. Although contamination levels are much higher in LCSP than in Lago Puyehue, a peak in anthropogenic Pb is recorded during the same period (1974–1976) at both sites. This maximum contamination level is consistent with increased industrial activity in the vicinity of Concepción.This research was partly supported by the Belgian OSTC project EV/12/10B "A continuous Holocene record of ENSO variability in southern Chile", by the Scientific Co-operation Exchange Program between University of Concepción (Chile) and University of Liège (Belgium) funded by the Belgian CGRI (Commissariat Général aux relations internationales de la Communauté Française de Belgique), and by Fondecyt project Nº 1070508. S.B. is supported by a BAEF fellowship (Belgian American Educational Foundation), and by an EU Marie Curie Outgoing Fellowship under the FP6 programme

    Human bones tell the story of atmospheric mercury and lead exposure at the edge of Roman World

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    We thank Museo de Pontevedra and Dirección Xeral de Patrimonio Xuntade Galicia for providing access to skeletal collections. OLC is funded by ED481D 2017/014Xunta de Galicia. This work was supported bythe projects: Galician Paleodiet (ED481D 2017/014), Consiliencia network (ED 431D2017/08), GPC (ED431B 2018/20) all funded by Xunta de Galicia.Peer reviewedPublisher PD
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