Semi-automatic determination of the carbon and oxygen stable isotope compositions of calcite and dolomite in natural mixtures
| Autor: | Giovanni Aloisi, Christophe Lécuyer, Gilles Escarguel, M. Baudrand, François Martineau, Vincent Grossi, Jean-Marie Rouchy, M. M. Blanc-Valleron, François Fourel |
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| Přispěvatelé: | Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), French National Research Agency (ANR) Institut Universitaire de France, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
SAMPLES
Dolomite Mineralogy chemistry.chemical_element [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Fractionation 010502 geochemistry & geophysics Mass spectrometry 01 natural sciences chemistry.chemical_compound Geochemistry and Petrology Environmental Chemistry Phosphoric acid TEMPERATURE 0105 earth and related environmental sciences BASIN Calcite Isotope Stable isotope ratio FRACTIONATION SPAIN 010401 analytical chemistry Pollution RATIOS 0104 chemical sciences SEDIMENTARY chemistry Carbon MARINE Geology |
| Zdroj: | Applied Geochemistry Applied Geochemistry, Elsevier, 2012, 27 (1), pp.257-265. ⟨10.1016/j.apgeochem.2011.11.003⟩ Applied Geochemistry, 2012, 27 (1), pp.257-265. ⟨10.1016/j.apgeochem.2011.11.003⟩ |
| ISSN: | 0883-2927 |
| Popis: | International audience; A semi-automatic, on-line method was developed to determine the delta(13)C and delta(18)O values of coexisting calcite and dolomite. An isotopic mass balance is used to calculate the compositions of dolomite after having measured that of calcite and of the "bulk'' sample. The limit of validity of this method is established by performing isotopic measurements of artificial mixtures made of precisely weighted and isotopically-characterised dolomite and calcite. The accuracy and repeatability of the calculation of dolomite delta(13)C and delta(18)O are statistically determined with a Monte-Carlo procedure of error propagation. Stable isotope ratios are determined by using an automated MultiPrep T system on-line with an isotope-ratio massspectrometer (IRMS). The reaction time and the temperature of reaction were optimised by comparing the results with the isotopic composition of known mixtures. The best results were obtained by phosphoric acid digestion after 20 min at 40 degrees C for calcite and 45 min at 90 degrees C for dolomite. This procedure allows an accurate determination of the isotopic ratios from small samples (300 mu g). Application of this protocol to natural mixtures of calcite and dolomite requires the accurate determination of the relative abundance of calcite and dolomite by combining Melieres manocalcimetry (MMC) and X-ray diffractometry (XRD). |
| Databáze: | OpenAIRE |
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