Inter-calibration of a proposed new primary reference standard AA-ETH Zn for zinc isotopic analysis

We have prepared a large volume of pure, concentrated and homogenous zinc standard solution. This new standard solution is intended to be used as a primary reference standard for the zinc isotope community, and to serve as a replacement for the nearly exhausted current reference standard, the so-called JMC-Lyon Zn. The isotopic composition of this new zinc standard (AA-ETH Zn) has been determined through an inter-laboratory calibration exercise, calibrated against the existing JMC-Lyon standard, as well as the certified Zn reference standard IRMM-3702. The data show that the new standard is isotopically indistinguishable from the IRMM-3702 zinc standard, with a weighted δ66/64Zn value of 0.28 ± 0.02‰ relative to JMC-Lyon. We suggest that this new standard be assigned a δ66/64Zn value of +0.28‰ for reporting of future Zn isotope data, with the rationale that all existing published Zn isotope data are presented relative to the JMC-Lyon standard. Therefore our proposed presentation allows for a direct comparison with all previously published data, and that are directly traceable to a certified reference standard, IRMM-3702 Zn. This standard will be made freely available to all interested labs through contact with the corresponding author

Late Permian–Early Triassic environmental changes recorded by multi-isotope (Re-Os-N-Hg) data and trace metal distribution from the Hovea-3 section, Western Australia

The temporal coincidence between the Late Permian mass extinction (LPME) and the emplacement of Siberian Trap basalts suggests a causal link between the two events. Here, we discuss stratigraphic changes of organic and inorganic (including isotopic) geochemical properties of marine sediments across the Permian–Triassic boundary (PTB) in the Hovea-3 core, Western Australia, a key PTB section in the southern Neo-Tethys ocean. These data are compared with published data from the Meishan section, southern China, and from the Opal Creek section in western Canada, providing a view of Tethys and Panthalassa changes at the PTB. Trace metal and N-isotopic data, together with organic matter properties suggest that anoxic conditions were established prior to the LPME, intensified close to the LPME, and continued with photic-zone euxinia into the Early Triassic. For the Hovea-3 section, Re-Os ages confirm Changhsingian (253.5 ± 1.4 Ma) deposition of the dated interval sampled immediately below the stratigraphic level characterized by major lithological and isotopic changes. Evaluation of Re-Os, N, and Hg elemental and isotopic data for Hovea-3 suggests that anoxic conditions in the latest Permian were generally unrelated to direct magmatic contributions. A major increase in the initial Os isotopic ratio of Lower Triassic shales suggest an ~8× increase in the Early Triassic continental runoff, based on moderately conservative assumptions for end-members contributing Os to the Permian–Triassic ocean. Comparison to other PTB sections confirms a global signal of increasing Re/Os ratios in the Late Permian, and major and long-lived changes in the isotopic composition of the post-extinction ocean. A distinct peak in Hg concentrations carrying a volcanic isotopic signature, also identified in other PTB sections, likely represents a major pulse of Siberian Trap volcanism. This Hg peak in the Hovea-3 section, however, is detected above the stratigraphic level containing multiple other widely recognized and more permanent geochemical changes. Therefore, direct volcanic inputs to the Permian–Triassic Ocean likely post-date the LPME in this Western Australian section

Earliest evidence of pollution by heavy metals in archaeological sites

Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.Francisco J. Jiménez Palacios and to the Analytical Chemistry Department (Sevilla University) are gratefully acknowledged for their help in the use of Carbolite electric oven. A.G.-A. was supported by a Marie Curie Intra-European Fellowship of the 7th Framework Programme for Research, Technological Development and Demonstration (European Commission). R.B. is a Beatriu de Pinós-A post-doctoral fellowship recipient (Generalitat de Catalunya and COFUND Marie Curie Actions, EU-FP7). This work also was partially financed by projects 19434/PI/14 Fundación Séneca, HARP2013-44269P, CGL-BOS-2012-34717, CGL2012-38434-C03-03 and CGL2012-38358 Ministerio de Economía y Competitividad, 2014 SGR 900 and 2014/100573 Generalitat de Catalunya-AGAUR, RNM 432 Research Group 179 (Junta de Andalucia) and MEXT-Japan

Bem-morar em São Paulo, 1880-1910: Ramos de Azevedo e os modelos europeus

Domestic architecture achieves a great impulse in the second half of XIXth-century. From Europe to the whole world, models are conformed to the new social order and spread as industrialization takes command. Dwelling becomes the main concern among architects. New concepts are developed for the ideal house for 011 social strata: working class, middle-class, bourgeoisie. This essay traces the introduction in São Paulo of European formal patterns and principies Ihygiene, salubrity, comfort, social and domestic rites, social visibility) through the activity of F. P. Ramos de Azevedo! 1851-19281. The main projects he conceived for the local bourgeoisie are analysed.A arquitetura doméstica tem um grande impulso no século XIX. Da Europa são difundidos, para todo mundo, os modelos conformados à nova ordem social e à industrialização. A residência se transforma numa preocupação central dos arquitetos. Desenvolvem-se novos conceitos para casa ideal para todas as camadas sociais: operários, classe média, burguesia. Este artigo retrata, em São Paulo, a introdução de padrões formais e princípios (de higiene, salubridade, conforto, ritos sociais e domésticos, as aparências). a partir da atividade de F. P. Ramos de Azevedo (1851-19201. Analisam-se os principais projetos que ele desenvolveu para a burguesia local

Strontium isotope analysis in ancient glass from South Asia using portable laser ablation sampling

International audienceIn order to carry out strontium isotope analysis, glass artifacts from South Asia were sampled with portable laser (pLA), a relatively novel sampling technique, that leaves damages invisible to the naked eye. Subsequently, thermal ionization mass spectrometry (TIMS) was used to obtain strontium isotope ratios after sample dissolution and separation. With this study, the goal was two-fold: to determine whether the measurements of strontium isotope ratios were impacted by using a portable laser as a sample tool, and also to assess the pertinence of using strontium isotope ratios to provenance Indian glass. Despite a deterioration of the precision of the measurement of the strontium isotope ratios for artifacts sampled with pLA compared to traditional sampling method, the strontium isotope ratios of certain Indian glass are so different that this does not affect their separation but comparison of datasets obtained using standard methods and pLA might be challenging

Availability of soil cadmium using stable and radioactive isotope dilution

The aim of this research was (i) to compare the use of stable (111Cd) and radioactive (109Cd) isotopes for assessing the isotopically exchangeable pool of Cd (ECd), (ii) to evaluate a simpler alternative method, the extraction by 1 M CaCl2, (iii) to determine ECd in a wide range of soil and contamination types and (iv) to assess how ECd can be affected by the soil characteristics. Measurement with 111Cd gave equivalent but more repeatable results than those of 109Cd. Increasing the acidity of the spike solution led to an overestimation of ECd. Extraction by 1 M CaCl2 generally gave similar values to isotope dilution. Measured on 29 soil samples, ECd was on average 44% of the total Cd (CdT). The cultivated soils showed the highest relative cadmium availability (ECd/CdT = 46% on average) and the geochemically enriched soils the lowest (20%). For the whole sample set, ECd variance was mainly explained by the correlation with CdT (r = 0.86), while ECd/CdT was negatively correlated with pH (r = − 0.73). In the cultivated soils, ECd increased with CEC (r = 0.94), while ECd/CdT decreased with increasing iron content (r = − 0.91)

Urban/peri-urban aerosol survey by determination of the concentration and isotopic composition of Pb collected by transplanted lichen Hypogymnia physodes

In the northeastern part of France, around the city of Metz, lichens (Hypogymnia physodes) have been transplanted from a single reference site to five different sites: (i) the reference site itself, (ii and iii) two peri-urban sites, (iv) a site in the proximity of a highway, and (v) a final one close to an industrial site. The dynamics of two different system set-ups (one covered and one uncovered) were evaluated. Samples have been collected 14, 34, and 68 days after transplantation. Lead concentrations already accumulated in the thallus, and the corresponding Pb isotopic compositions have been measured by quadrupole-based ICP-mass spectrometry. A systematic difference between the two setups is found for Pb concentrations, with the higher concentrations measured in lichens from the uncovered devices. Lead concentrations in lichens from the covered devices were found to be lower than or equal to the original concentration. Also the Pb isotopic compositions show a systematic difference between the devices, with the Pb isotopic composition have been present in lichens from the uncovered device being more radiogenic. Substantial changes in the isotopic composition of Pb are recorded for lichens from the uncovered device (from about 1.15 up to 1.22 for the Pb-206/Pb-207 ratio), in some cases already after only 34 days of exposure. The increases in the Pb concentration and the Pb-206/Pb-207 ratio and the differences between the devices are explained by hypothesizing that (i) different Pb sources give rise to a different size distribution of aerosol particles and (ii) in the lichens present in the covered setup, a part of the aerosol particles cannot be incorporated. Also the influence of the source of the aerosols to lichens after transplantation is evaluated and the potential influence of biological reactions is discussed