UWG-2, a garnet standard for oxygen isotope ratios: Strategies for high precision and accuracy with laser heating

Valley, John W.; Kitchen, Nami; Kohn, Matthew J.; Niendorf, Christopher R.; Spicuzza, Michael J.

doi:10.1016/0016-7037(95)00386-x

Cited by 639 publications

(322 citation statements)

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“…Measurements of the UWG-2 garnet reference material gave δ 18 O = 5.66 ± 0.08 ‰ (1σ, n=9), in good agreement with the reference value of + 5.74 ± 0.15 ‰ given by Valley et al (1995). Based on long-term reproducibility, an analytical uncertainty of ±0.2 ‰ is assumed for the samples analyzed in this study.…”

Section: Oxygen Isotopic Analysessupporting

confidence: 85%

A stable (Li, O) and radiogenic (Sr, Nd) isotope perspective on metasomatic processes in a subducting slab

et al. 2011

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Two distinct types of eclogites from the Raspas Complex (Ecuador), which can be distinguished based on petrography and trace element geochemistry, were analyzed for their stable (Li, O) and radiogenic (Sr, Nd) isotope signature to constrain metasomatic changes due to fluid-overprinting in metabasaltic rocks at high-pressure conditions and to identify fluid sources. MORB-type eclogites are characterized by a relative LREE depletion similar to MORB. High-pressure (HP) minerals from this type of eclogite have highly variable oxygen isotope compositions (garnet: +4.1 to +9.

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Section: Oxygen Isotopic Analysessupporting

confidence: 85%

A stable (Li, O) and radiogenic (Sr, Nd) isotope perspective on metasomatic processes in a subducting slab

et al. 2011

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“…Oxygen isotope ratios (δ 18 O, per mil notation) of 26 fresh, microphenocryst-free glass chips, covering the range of rock types (Table 1), were determined at the CO 2 -laser-fluorination laboratory at the University of Wisconsin, Madison, following methods described in Valley et al (1995) and Spicuzza et al (1998). Aliquots of 2.4-3.2 mg were treated with BrF 5 overnight, and then individually heated with a CO 2 laser in the presence of BrF 5 .…”

Section: Oxygen Isotope Analyses and Resultsmentioning

confidence: 99%

“…Aliquots of 2.4-3.2 mg were treated with BrF 5 overnight, and then individually heated with a CO 2 laser in the presence of BrF 5 . Measurements were standardized with 4-5 analyses of UWG-2 garnet standard per day (δ 18 O = 5.8‰; Valley et al, 1995), and are reported in standard δ-notation relative to Standard Mean Ocean Water (SMOW). Reproducibility of the standard during each session was better than ±0.15‰ (2SD).…”

Section: Oxygen Isotope Analyses and Resultsmentioning

confidence: 99%

Volatile abundances and oxygen isotopes in basaltic to dacitic lavas on mid-ocean ridges: The role of assimilation at spreading centers

et al. 2011

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a b s t r a c t a r t i c l e i n f oMost geochemical variability in MOR basalts is consistent with low-to moderate-pressure fractional crystallization of various mantle-derived parental melts. However, our geochemical data from MOR highsilica glasses, including new volatile and oxygen isotope data, suggest that assimilation of altered crustal material plays a significant role in the petrogenesis of dacites and may be important in the formation of basaltic lavas at MOR in general. MOR high-silica andesites and dacites from diverse areas show remarkably similar major element trends, incompatible trace element enrichments, and isotopic signatures suggesting similar processes control their chemistry. In particular, very high Cl and elevated H 2 O concentrations and relatively light oxygen isotope ratios (~5.8‰ vs. expected values of~6.8‰) in fresh dacite glasses can be explained by contamination of magmas from a component of ocean crust altered by hydrothermal fluids. Crystallization of silicate phases and Fe-oxides causes an increase in δ 18 O in residual magma, but assimilation of material initially altered at high temperatures results in lower δ 18 O values. The observed geochemical signatures can be explained by extreme fractional crystallization of a MOR basalt parent combined with partial melting and assimilation (AFC) of amphibole-bearing altered oceanic crust. The MOR dacitic lavas do not appear to be simply the extrusive equivalent of oceanic plagiogranites. The combination of partial melting and assimilation produces a distinct geochemical signature that includes higher incompatible trace element abundances and distinct trace element ratios relative to those observed in plagiogranites.

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“…The following δ 18 O values were obtained for international standards in the course of the study: NBS-28 quartz 9.66 ±0.05‰ (n=10; theoretical value: 9.58‰), NBS-30 biotite 5.12 ±0.08‰ (n=4; theoretical value: 34 A. Demény et al Central European Geology 50, 2007 5.1‰), UWG-2 garnet 5.88 ±0.13‰ (n=20; theoretical value: 5.8‰, Valley et al 1995). Based on these data and the reproducibilities of duplicate data, the δ 18 O values of samples are precise within 0.15‰.…”

Section: Methodsmentioning

confidence: 99%

Stable isotope compositions of the Penninic ophiolites of the Kõszeg-Rechnitz series

Demény¹,

Vennemann²,

Koller³

2007

Central European Geology

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The ophiolitic rocks of the easternmost Penninic unit, the Kõszeg-Rechnitz series, were analyzed for their H, C and O stable isotope compositions. Serpentinite, gabbro, blueschist, talc deposits, ophicarbonates, as well as calcite and inclusion fluids from quartz segregation veins were analyzed in order to determine the effects of different metamorphic events on the stable isotope compositions.The oxygen isotope compositions have a wide range depending on rock type and locality. Gabbro and serpentinite of Bienenhütte (Bernstein Window) have preserved mantle-like δ 18 O values (5.9 to 6.3‰; all values are in ‰ relative to V-SMOW), whereas the serpentinite of Glashütten and Rumpersdorf (Kõszeg-Rechnitz Window) and the silicate minerals of the ophicarbonate rocks show a strong 18 O-enrichment (up to 16.2‰). The 18 O-enrichment may have been induced by lowtemperature serpentinization or interaction with 18 O-rich fluids that had been in equilibrium with sedimentary rocks. Contrary to the O isotope compositions, the H isotope compositions seem to be homogeneous in the entire series, with D values of -63 ± 7‰. Only some serpentinite rocks were depleted in D (down to -106‰), usually regarded as a result of interaction with meteoric water infiltrating during late-stage metamorphism. The meteoric water infiltration was rather limited, as even samples taken directly from slickensides within serpentinite bodies preserved isotopic compositions close to those of the bulk series. H and O isotope compositions of fluids mobilized in the metasedimentary rocks of the Penninic unit during the main metamorphic stage were determined by analyzing inclusion fluids and calcites in quartz-carbonate veins. The isotope compositions indicate interaction between these fluids and the ophiolite series, although relative deuterium enrichment has been preserved in the ophiolitic rocks.The strong D-enrichment characteristic for oceanic crust that has experienced high-temperature interaction with seawater was not detected. However, the H isotope compositions obtained for the Kõszeg-Rechnitz series indicate that subduction of the Penninic oceanic crust and the associated devolatilization may have been potentially responsible for mantle metasomatism, resulting in H Addresses: A. Demény: H-1112 Budapest, Budaörsi út 45, Hungary, e-mail: demeny@geochem.hu T. W. Vennemann: L'Anthropole, CH-1015 Lausanne, Switzerland F. Koller: Althanstr. 14, 1090 Vienna, Austria Received: January 2, , accepted: March 28, 2007 1788-2281/$ 20.00 © 2007 Akadémiai Kiadó, Budapest Central European Geology, Vol. 50/1, pp. 29-46 (2007 DOI: 10.155610. /CEuGeol.50.2007 isotope compositions of about -40‰, similar to the range determined from mantle-derived amphibole megacrysts (Demény et al. 2005). To conclude, the present dataset is discussed in the light of earlier studies on the formation of the Sopron leucophyllite.

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UWG-2, a garnet standard for oxygen isotope ratios: Strategies for high precision and accuracy with laser heating

Cited by 639 publications

References 18 publications

A stable (Li, O) and radiogenic (Sr, Nd) isotope perspective on metasomatic processes in a subducting slab

A stable (Li, O) and radiogenic (Sr, Nd) isotope perspective on metasomatic processes in a subducting slab

Volatile abundances and oxygen isotopes in basaltic to dacitic lavas on mid-ocean ridges: The role of assimilation at spreading centers

Stable isotope compositions of the Penninic ophiolites of the Kõszeg-Rechnitz series

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