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Showing 1 to 8 of 8 for “"delta18O"”.
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Laurentide ice sheet meltwater influences and millennial-scale climate oscillations on the northwestern slope of the Gulf of Mexico during Marine Isotope Stage 6 and Termination II
… II. The results of this study show that the delta18O record of planktonic foraminifer G. ruber contains millennial-scale climate oscillations during MIS 6, a series of meltwater spikes, and a climate reversal during Termination II. Paired delta18O -- Mg/Ca data across these events reveal that …
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Sodium metasomatism and magnesio-riebeckite mineralization in the Wilson Ridge pluton
… containing hydrothermal amphiboles have lower delta18O values (+3.68‰ to +6.97‰) than unaltered granitoid rocks (delta 18O values +6.04‰ to +9.23‰).
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Pedogenic gypsum of southern New Mexico: Genesis, morphology, and stable isotopic signature
… the hydration water of pedogenic gypsum and the delta18O/deltaD ratios of meteoric water. However, a pedogenic origin for the sampled gypsum was not clearly supported and the results from this procedure were not compared to other paleoclimatic indicators. Therefore, the goals of this study were, …
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Nitrate and Ammonium Transformation and Fate in Groundwater of an Agricultural Watershed: An Isotope and Geochemistry Approach
… site. Naturally occurring stable isotopes (delta18O and delta 2H), which are sensitive to seasonality of recharge, were used in groundwater and precipitation to provide an estimate of recharge and mass loading to the aquifer. The significance of direct infiltration through cultivated …
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Spatial variability in modern brachiopod assemblages: paleoecological and geochemical implications
… assemblages. The paleoclimatic utility of delta18O in the phosphatic phase of lingulid brachiopod shells requires valve secretion in equilibrium with seawater, an assumption tested (and rejected) when analyzed at scales ranging from millimeters to kilometers. By contrast, biological …
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The geochemistry of carbonate-hosted Pb-Zn-Ag mineralization in the Lavrion District, Attica, Greece: fluid inclusion, stable isotope, and rare earth element studies
… of calcite (delta13C = -15.6 to -1.5‰ and delta18O = -9.2 to 17.3‰) intergrown with sulfides reflect variable exchange of the ore-bearing fluid with the Upper and Lower marbles and proximity to the Plaka granodiorite. Post Archean Australian Shale (PAAS)-normalized rare earth and yttrium …
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Magnetized models for the formation of the moon
… e.g., the lunar oxygen isotope ratio \delta17O/\delta18O falls atop the terrestrial fractionation line (the “isotope crisis;” see Melosh, 2014). Unless the proto-Earth and impactor were isotopically identical, the giant impact hypothesis requires vigorous mixing between impactor- and …
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Trockenheitsreaktionen und holzanatomische Eigenschaften der Zitter-Pappel (Populus tremula L.) – Physiologie und QTL-Mapping
Holz aus Kurzumtriebsplantagen (KUP) mit Pappeln (Populus spp.) kann eine bedeutende Rolle im Mix der Bioenergieressourcen in Deutschland spielen. Trotz eines günstigen Energieinput-Energieoutput-Verhältnisses ist das Erreichen wirtschaftlich zufriedenstellender Ergebnisse mit KUP jedoch auf den …