Littérature scientifique sur le sujet « High-precision Sr isotopes »

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Articles de revues sur le sujet "High-precision Sr isotopes"

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Yobregat, Elsa, Caroline Fitoussi et Bernard Bourdon. « A new method for TIMS high precision analysis of Ba and Sr isotopes for cosmochemical studies ». Journal of Analytical Atomic Spectrometry 32, no 7 (2017) : 1388–99. http://dx.doi.org/10.1039/c7ja00012j.

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Thorrold, Simon R., et Stephen Shuttleworth. « In situ analysis of trace elements and isotope ratios in fish otoliths using laser ablation sector field inductively coupled plasma mass spectrometry ». Canadian Journal of Fisheries and Aquatic Sciences 57, no 6 (1 juin 2000) : 1232–42. http://dx.doi.org/10.1139/f00-054.

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We applied laser ablation sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) to the analysis of trace element and isotopic signatures in fish otoliths. Manganese, Sr, and Ba profiles across juvenile Atlantic croaker (Micropogonias undulatus) otoliths, expressed as ratios to Ca, showed considerable spatial and temporal variations that were presumably reflective of variations in water chemistry over the same scales. Differences in otolith Mn:Ca ratios between adjacent rivers in Pamlico Sound, North Carolina, may be related to dissolved oxygen levels in the rivers through reductive release of Mn2+ from sediments. Strontium and Ba profiles appeared to accurately reflect differences in dissolved Sr and Ba in freshwater end-members, both between Pamlico Sound and Chesapeake Bay and between seasons within Chesapeake Bay. High-precision analyses of Sr:Ca ratios in a black drum (Pogonias cromis) otolith showed distinctive quasi-sinusoidal cycles that were correlated with validated annual bands. Analyses of Sr and Pb isotopes, in otoliths and standard reference material, respectively, found that SF-ICP-MS produced accurate and precise estimates of isotope ratios in both solution-based and laser ablation assays.
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Barnett-Johnson, Rachel, Frank C. Ramos, Churchill B. Grimes et R. Bruce MacFarlane. « Validation of Sr isotopes in otoliths by laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) : opening avenues in fisheries science applications ». Canadian Journal of Fisheries and Aquatic Sciences 62, no 11 (1 novembre 2005) : 2425–30. http://dx.doi.org/10.1139/f05-194.

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Advances in probe-based mass spectrometry allow for high spatial resolution of elemental and isotopic signatures in fish otoliths that can be used to address fundamental questions in fisheries ecology. Analyses of Chinook salmon (Oncorhynchus tshawytscha) otoliths from two river populations yield identical 87Sr/86Sr ratios using laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) and thermal ionization mass spectrometry (TIMS). Results were obtained from freshwater otoliths with low Sr concentrations (300–800 ppm) using high spatial resolution (50 µm) corresponding to temporal histories of ~12 days fish growth. Low natural variation in 87Sr/86Sr among otoliths from the same rivers allows for conservative estimates of external precision of techniques. Thus, we demonstrate that Sr isotope ratios obtained by LA-MC-ICPMS can be accurate and precise, bypassing the time-intensive sample preparation required by microdrilling and TIMS. This technique opens the use of Sr isotopes for broader ecological questions requiring large sample sizes to characterize nursery habitats, metapopulation dynamics, and stock discrimination similar to studies that focus on elemental concentrations, thereby providing a more robust tool for some freshwater and diadromous fishes.
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Nan, Xiaoyun, Huimin Yu, Jinting Kang et Fang Huang. « Re-visiting barium isotope compositions of mid-ocean ridge basalts and the implications ». JUSTC 52, no 3 (2022) : 1. http://dx.doi.org/10.52396/justc-2021-0276.

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Barium (Ba) isotopes can be used as potential tracers for crustal material recycling in the mantle. Determination of the Ba isotope composition of the depleted mantle is essential for such applications. However, Ba isotope data for mantle-derived basalts are still rare. In this study, we reported high-precision Ba isotope data of 30 oceanic basalts including 25 mid-ocean ridge basalts (MORBs) from geochemically and geologically diverse mid-ocean ridge segments and five back-arc basin basalts. The δ<sup>138/134</sup>Ba values of these samples varied from −0.06‰ to +0.11‰, with no systematic cross-region variation. Together with published data, we constrained the average δ<sup>138/134</sup>Ba of global MORBs to +0.05‰±0.09‰ (2 standard deviation, <i>n</i> = 51). Based on depleted MORBs that have (La/Sm)<sub>N</sub> < 0.8, low <sup>87</sup>Sr/<sup>86</sup>Sr (< 0.70263), and low Ba/Th < 71.3, we estimated the average δ<sup>138/134</sup>Ba of the depleted MORB mantle (DMM) as + 0.05‰ ± 0.05‰ (2SD, <i>n</i> = 16) that is significantly lower than the DMM (≈ 0.14‰) reported previously. If a new estimation of the DMM is applied, it is unreasonable to infer that the Ba isotope signatures of the “enriched-type” MORBs (E-MORBs) could be attributed to pervasive sediment recycling in the upper mantle. We, therefore, conclude that the Ba isotope compositions of the E-MORBs could be sourced from the incorporation of subducted altered oceanic crust and/or sediments depending on the Ba isotope composition and other geochemical information of the local mantle.
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Armstrong, Richard Lee, Randall R. Parrish, Peter van der Heyden, Krista Scott, Dita Runkle et Richard L. Brown. « Early Proterozoic basement exposures in the southern Canadian Cordillera : core gneiss of Frenchman Cap, Unit I of the Grand Forks Gneiss, and the Vaseaux Formation ». Canadian Journal of Earth Sciences 28, no 8 (1 août 1991) : 1169–201. http://dx.doi.org/10.1139/e91-107.

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The protolith age of high-grade metamorphic rocks exposed in structurally deep parts of the Omineca Crystalline Belt has been the subject of investigation and controversy for decades. We have applied multiple isotopic dating techniques to rocks of three structural culminations: the Monashee complex (which includes the Frenchman Cap and Thor–Odin gneiss domes), the Grand Forks horst, and the Vaseaux Formation, which lies in the footwall of the Okanagan Valley fault.Frenchman Cap core gneisses contain highly radiogenic Sr that scatters about a 2206 ± 117 Ma (1σ) Rb–Sr isochron with 87Sr/86Sr initial ratio of 0.700 ± 0.002. Monazite and zircon dates for the same rocks are 1851 ± 7 to 2103 ± 16 Ma (only U–Pb dates are given with 2σ errors), with lower intercepts from about 100 to 300 Ma. Sm–Nd whole-rock and crustal-residence (TDM) dates are 2.3 ± 0.2 Ga. Mafic–felsic layering in the core gneiss is also of Early Proterozoic age. There is no geochronometric evidence for Late Proterozoic or Mesozoic migmatization.Frenchman Cap mantling gneisses, including samples from above the Monashee décollement, have radiogenic Sr and unradiogenic Nd compositions that are not consistent with current inferences of a Late Proterozoic to Paleozoic depositional age. Two intrusive granitic rocks, which cut mantling gneiss, are either Early Proterozoic or Mesozoic–Cenozoic with a Proterozoic Sr isotopic signature acquired by assimilation of core gneiss. One other intrusive studied is probably Paleocene Ladybird granite. The age of the mantling gneiss is not yet consistently resolved.Grand Forks Gneiss Unit I paragneiss gives radiogenic whole-rock Sr, zircon U–Pb upper intercept, and Sm–Nd whole-rock crustal-residence dates of 1.7 ± 0.4 Ga, 1681 ± 3 Ma (2σ, but the apparent high precision is very dependent on the assumption made about the time of Pb loss), and 1.9 ± 0.3 Ga, respectively. Unit II and younger Grand Forks Gneiss units are Late Proterozoic or Phanerozoic. All isotope systems have been considerably reset on a centimetre to metre scale by Mesozoic–Cenozoic regional metamorphism. Grand Forks Sr, Pb, and Nd isotope data are much like those for Spokane area pre-Purcell basement.Vaseaux Formation micaceous schist and gneiss give radiogenic whole-rock Sr, zircon U–Pb upper intercept, and Sm–Nd crustal-residence dates of 2.1 ± 0.6 Ga, 1899 ± 49 Ma (2σ), and 2.2 ± 0.1 Ga, respectively. Hornblende-bearing schist and gneiss contain much less radiogenic Sr and more radiogenic Nd. The latter are either tectonic intercalations of Late Proterozoic to Paleozoic eugeosynclinal rocks or Mesozoic–Cenozoic mixtures of mantle-derived magma and older crustal rock. The Vaseaux Formation paragneiss is similar isotopically to paragneiss in the Frenchman Cap core gneiss. This may indicate a similar age, or that Vaseaux sedimentary rocks could be much younger and isochemically derived from a basement of Frenchman Cap character. The first alternative is favored because the three isotope systems are usually not preserved in unison through sedimentary processes. Sr isotopes, in particular, do not usually preserve a provenance age.In all three areas, late Mesozoic to early Cenozoic metamorphic monazite, hornblende, muscovite, and biotite dates provide a record of cooling from a Cretaceous to Paleocene culmination of regional metamorphism, with particularly rapid cooling during Paleocene to Eocene crustal extension and tectonic unroofing.The localities studied are tectonic windows on structural culminations that expose basement that we infer to be part of North America. Their ages fit the pattern of basement ages established for the stable craton. Their extent is consistent with the reconstruction of compressed miogeoclinal rocks. The eastern half of the Cordilleran region on both sides of the United States – Canada border is underlain by Early Proterozoic basement that was attenuated in Late Proterozoic time, compressed during Mesozoic–Cenozoic orogeny, and finally extended in early Cenozoic collapse of the thickened crust. During Mesozoic–Cenozoic orogeny the sedimentary cover of that basement was pushed approximately 200 km eastward and replaced by allochthonous terranes. The tectonic displacements documented in the southern Canadian Cordillera are truly exceptional.
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Ku, Teh-Lung, M. Ivanovich et Shangde Luo. « U-Series Dating of Last Interglacial High Sea Stands : Barbados Revisited ». Quaternary Research 33, no 2 (mars 1990) : 129–47. http://dx.doi.org/10.1016/0033-5894(90)90014-c.

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AbstractU-series chronologies of the emerged coral limestone terraces on Barbados, West Indies, together with those of the terraces from New Guinea, have formed the basis for most late Pleistocene eustatic models. The so-called “Barbados sea level model” has been challenged in recent years, however. A major issue is whether during oxygen isotope stage 5e, when Rendezvous Hill reef complex on Barbados Island formed, the sea rose above the present position for one relatively brief period of <10,000 yr, or for two or more periods spanning approximately from 140,000 to 115,000 yr B.P. Evidence for the latter scenario has not come from initial studies of Barbados but from elsewhere; it is also inconclusive because of the dating uncertainties involved. We have carried out careful redeterminations of U-series ages on a suite of 29 Acropora palmata samples systematically collected from four of the lowest terraces on the island. Diagenetic disturbance may have caused the age spreads at some sampling outcrops. A model for the diagenetic exchange of uranium isotopes in coral samples with those in groundwater explains the anomalous 234U/238U ratios in samples with apparently unaltered mineralogy (aragonite) and trace element (Mg and Sr) chemistry. It shows that age dispersions of 5–10% can be engendered by a U exchange coefficient of the order of 10−6 yr−1. The lower-limit terrace ages, estimated from averaging the multiple measurements, are 81,000 ± 2000 yr (Worthing), 105,000 ± 1000 yr (Ventnor), 120,000 ± 2000 yr (Maxwell), and 117,000 ± 3000 yr (Rendezvous Hill). No evidence was found of previously inferred bipartite sea levels centering around 118,000 and 135,000 yr ago. This study documents the need of dating coral with the high precision/sensitivity mass-spectrometric techniques for future resolution of the temporal relationships among sea level changes, climate oscillations, and astronomical forcing—relationships originally addressed by the Barbados sea level model.
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Di Salvo, Sara, Eleonora Braschi, Martina Casalini, Sara Marchionni, Teresa Adani, Maurizio Ulivi, Andrea Orlando et al. « High-Precision In Situ 87Sr/86Sr Analyses through Microsampling on Solid Samples : Applications to Earth and Life Sciences ». Journal of Analytical Methods in Chemistry 2018 (2018) : 1–20. http://dx.doi.org/10.1155/2018/1292954.

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An analytical protocol for high-precision, in situ microscale isotopic investigations is presented here, which combines the use of a high-performing mechanical microsampling device and high-precision TIMS measurements on micro-Sr samples, allowing for excellent results both in accuracy and precision. The present paper is a detailed methodological description of the whole analytical procedure from sampling to elemental purification and Sr-isotope measurements. The method offers the potential to attain isotope data at the microscale on a wide range of solid materials with the use of minimally invasive sampling. In addition, we present three significant case studies for geological and life sciences, as examples of the various applications of microscale 87Sr/86Sr isotope ratios, concerning (i) the pre-eruptive mechanisms triggering recent eruptions at Nisyros volcano (Greece), (ii) the dynamics involved with the initial magma ascent during Eyjafjallajökull volcano’s (Iceland) 2010 eruption, which are usually related to the precursory signals of the eruption, and (iii) the environmental context of a MIS 3 cave bear, Ursus spelaeus. The studied cases show the robustness of the methods, which can be also be applied in other areas, such as cultural heritage, archaeology, petrology, and forensic sciences.
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Lin, Jie, Yongsheng Liu, Haihong Chen, Lian Zhou, Zhaochu Hu et Shan Gao. « Review of High-Precision Sr Isotope Analyses of Low-Sr Geological Samples ». Journal of Earth Science 26, no 5 (octobre 2015) : 763–74. http://dx.doi.org/10.1007/s12583-015-0593-0.

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Nguyen Thi Kim, Dung, et Thuy Thai Thi Thu. « Study on the removal of interferences for the determination of ⁸⁷Sr/⁸⁶Sr isotopic ratio in petroleum drill-hole water samples using isotope dilution – inductively coupled plasma mass spectrometry (ID – ICP-MS) ». Nuclear Science and Technology 8, no 4 (1 septembre 2021) : 34–43. http://dx.doi.org/10.53747/jnst.v8i4.65.

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87Sr/86Sr isotopic ratio is one of the useful tools that can authenticate the original source of the natural products from the earth-created and/or geological processes. However, the effect of interferences in petroleum drill-holes water sample such as thickness of sample matrix or isotopic signal of 87Rb might cause the low precision of 87Sr/86Sr determination using quadrupole inductively coupled plasma spectrometry (ICP-MS). The elimination of these mentioned effects was thus studied by using the ion - exchange chromatography. Calcium in sample matrix was separated on anionite column (Bio-Rad AG1-X8 resin) in methanol medium with the high efficiency while rubidium wasremoved from strontium on cation exchange resin (Bio-Rad AG50-X8) with strontium recovery over 99%. The isotope dilution technique with 86Sr - enriched isotopic standard solution was used for the control of separation process. The 87Sr/86Sr isotopic ratio was thus determined using ICP-MS with the signal correction by a strontium isotopic ratio standard reference material (NIST SRM 987).
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Zhang, Zhuoying, Jinlong Ma, Le Zhang, Ying Liu et Gangjian Wei. « Rubidium purificationviaa single chemical column and its isotope measurement on geological standard materials by MC-ICP-MS ». Journal of Analytical Atomic Spectrometry 33, no 2 (2018) : 322–28. http://dx.doi.org/10.1039/c7ja00406k.

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A chromatographic procedure for Rb, K, Ba and Sr one-by-one separation from geological materials has been developed by using a single column with packing Sr-spec resin, followed by high-precision Rb isotope measurement by MC-ICP-MS.
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Thèses sur le sujet "High-precision Sr isotopes"

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Xia, Qikai. « High precision TIMS U-Th disequilibrium dating and C, O, Sr isotope-based multi-proxy palaeoclimatic study of Speleothems in Australia / ». [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18421.pdf.

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MARCHIONNI, SARA. « Caratteristiche isotopiche dei prodotti agroalimentari (vino) e dei loro substrati geologici con la finalità di definire parametri utili alla loro tracciabilità geografica ». Doctoral thesis, 2014. http://hdl.handle.net/2158/850903.

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In questo lavoro abbiamo cercato di mettere a punto una nuova procedura analitica per determinare il rapporto 87Sr/86Sr in prodotti della filiera agroalimentare, a partire dai suoli che costituiscono il substrato delle vigne fino al vino come prodotto finito passando per uva e mosto. Il nuovo protocollo analitico mostra un’ottima riproducibilità, comparabile con quella delle rocce in sistemi geologici, così da permettere la valutazione del possibile legame tra vino e substrato geologico delle vigne di produzione (Marchionni et al., 2013). In this work we have tried to develop a new analytical procedure to determine the 87Sr/86Sr ratio in the products of the food chain, from the soils that form the substrate of the vineyards to wine as a finished product by way of grapes and wine. The new analytical protocol shows good reproducibility, comparable with that of the rocks in geological systems, to enable assessment of the possible link between geological substratum of the vineyards and wine production (Marchionni et al., 2013).
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Chapitres de livres sur le sujet "High-precision Sr isotopes"

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Reimold, Wolf Uwe, Toni Schulz, Stephan König, Christian Koeberl, Natalia Hauser, Dschamilja Wannek et Ralf-Thomas Schmitt. « Genesis of the mafic granophyre of the Vredefort impact structure (South Africa) : Implications of new geochemical and Se and Re-Os isotope data ». Dans Large Meteorite Impacts and Planetary Evolution VI. Geological Society of America, 2021. http://dx.doi.org/10.1130/2021.2550(09).

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ABSTRACT This contribution is concerned with the debated origin of the impact melt rock in the central uplift of the world’s largest confirmed impact structure—Vredefort (South Africa). New major- and trace-element abundances, including those of selected highly siderophile elements (HSEs), Re-Os isotope data, as well as the first Se isotope and Se-Te elemental systematics are presented for the felsic and mafic varieties of Vredefort impact melt rock known as “Vredefort Granophyre.” In addition to the long-recognized “normal” (i.e., felsic, &gt;66 wt% SiO2) granophyre variety, a more mafic (&lt;66 wt% SiO2) impact melt variety from Vredefort has been discussed for several years. The hypothesis that the mafic granophyre was formed from felsic granophyre through admixture (assimilation) of a mafic country rock component that then was melted and assimilated into the superheated impact melt has been pursued here by analysis of the two granophyre varieties, of the Dominion Group lava (actually metalava), and of epidiorite mafic country rock types. Chemical compositions, including high-precision isotope dilution–derived concentrations of selected highly siderophile elements (Re, Os, Ir, Pt, Se, Te), and Re-Os and Se isotope data support this hypothesis. A first-order estimate, based on these data, suggests that some mafic granophyre may have resulted from a significant admixture (assimilation) of epidiorite to felsic granophyre. This is in accordance with the findings of an earlier investigation using conventional isotope (Sr-Nd-Pb) data. Moreover, these outcomes are in contrast to a two-stage emplacement model for Vredefort Granophyre, whereby a mafic phase of impact melt, derived by differentiation of a crater-filling impact melt sheet, would have been emplaced into earlier-deposited felsic granophyre. Instead, all chemical and isotopic evidence so far favors formation of mafic granophyre by local assimilation of mafic country rock—most likely epidiorite—by a single intrusive impact melt phase, which is represented by the regionally homogeneous felsic granophyre.
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Actes de conférences sur le sujet "High-precision Sr isotopes"

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Luu, Tu-Han, Edward Inglis, Pamela Gutierrez, Daniel Roberts et Catherine Chauvel. « High-precision Sr and Nd isotope measurements using a Nu TIMS ». Dans Goldschmidt2021. France : European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.4084.

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Di, Yankun, Evgenii Krestianinov et Yuri Amelin. « Effect of Fractionation Rate on High-Precision Multidynamic TIMS Sr Isotope Analysis and the 84Sr Abundance of the Earth ». Dans Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.571.

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Buzenchi, Anda, Hugo Moreira, Olivier Bruguier, Delphine Bosch et Bruno Dhuime. « High precision Sr isotope analyses in apatite by LA-MC-ICP-MS : from mineral inclusions in zircon to crustal evolution models ». Dans Goldschmidt2021. France : European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.5870.

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Yang, Yue-Heng. « High-Precision Sr-Nd-Hf-Pb Isotopic Composition of CGSG-1, CGSG-2, CGSG-4 and CGSG-5 Reference Materials by MC-ICP-MS and TIMS ». Dans Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.3011.

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