scholarly journals Preparation and storage of “laboratory standard” for measurement of hydrogen and oxygen isotopic ratio

2015 ◽  
Vol 57 (3) ◽  
pp. 295-306
Author(s):  
Kotaro NAKATA ◽  
Takuma HASEGAWA ◽  
Mari YOSHIOKA ◽  
Takahiro IIDA
Keyword(s):  
Isotopic Ratio ◽  
Oxygen Isotopic ◽  
And Storage ◽  
Oxygen Isotopic Ratio

Stepwise Fluorination Method for Determination of Oxygen Isotopic Ratio of Diatoms

2013 ◽  
Vol 40 (12) ◽  
pp. 1897-1901
Author(s):  
Tie-Jun LI ◽  
Hong-Wei LI ◽  
Xiu-Jin LIU ◽  
Lian-Jun FENG
Keyword(s):  
Isotopic Ratio ◽  
Oxygen Isotopic ◽  
Oxygen Isotopic Ratio

Variation of oxygen isotopic ratio during wine dealcoholization by membrane contactors: Experiments and modelling

2016 ◽  
Vol 498 ◽  
pp. 385-394 ◽  
Author(s):  
Roberto Ferrarini ◽  
Gian Maria Ciman ◽  
Federica Camin ◽  
Serena Bandini ◽  
Carlo Gostoli
Keyword(s):  
Isotopic Ratio ◽  
Oxygen Isotopic ◽  
Membrane Contactors ◽  
Oxygen Isotopic Ratio

scholarly journals Natural variability and anthropogenic effects in a Central Mediterranean core

2012 ◽  
Vol 8 (2) ◽  
pp. 831-839 ◽  
Author(s):  
S. Alessio ◽  
G. Vivaldo ◽  
C. Taricco ◽  
M. Ghil
Keyword(s):  
Isotopic Ratio ◽  
Forecast Error ◽  
Singular Spectrum Analysis ◽  
Low Frequency ◽  
Natural Variability ◽  
Central Mediterranean ◽  
Spectral Content ◽  
Frequency Components ◽  
Oxygen Isotopic ◽  
Complete Series

Abstract. We evaluate the contribution of natural variability to the modern decrease in foraminiferal δ18O by relying on a 2200-yr-long, high-resolution record of oxygen isotopic ratio from a Central Mediterranean sediment core. Pre-industrial values are used to train and test two sets of algorithms that are able to forecast the natural variability in δ18O over the last 150 yr. These algorithms are based on autoregressive models and neural networks, respectively; they are applied separately to each of the δ18O series' significant variability components, rather than to the complete series. The separate components are extracted by singular-spectrum analysis and have narrow-band spectral content, which reduces the forecast error. By comparing the sum of the predicted low-frequency components to its actual values during the Industrial Era, we deduce that the natural contribution to these components of the modern δ18O variation decreased gradually, until it reached roughly 40%, as early as the end of the 1970s.

Geology and footwall alteration of the South Bay massive sulphide deposit, northwestern Ontario, Canada

1983 ◽  
Vol 20 (12) ◽  
pp. 1862-1879 ◽  
Author(s):  
Tetsuro Urabe ◽  
S. D. Scott
Keyword(s):  
Lava Dome ◽  
Isotopic Ratio ◽  
Massive Sulphide Deposit ◽  
Sulphide Deposit ◽  
Ore Formation ◽  
Northwestern Ontario ◽  
Alteration Halo ◽  
Oxygen Isotopic ◽  
Bulk Chemistry ◽  
Kuroko Deposits

South Bay is an Archean volcanogenic massive Cu–Zn sulphide deposit having many features in common with the Kuroko deposits of Japan. The ore lenses overlie a quartz–feldspar porphyritic rhyolite (QFP) lava dome and are covered by or occur within rhyolitic tuff breccia that, together with rhyolite tuffs and lavas, is contained within a caldera-like structure.Footwall hydrothermal alteration at South Bay is detectable for several hundred metres from ore. "Unaltered" footwall QFP lava dome contains a mineral assemblage of quartz + two feldspars + two micas + epidote + calcite + ilmenite. Closer to the orebodies, K-feldspar, epidote, and biotite disappear first, followed by consumption of calcite, ilmenite, and albitized plagioclase. The most altered QFP has an assemblage of quartz + paragonite + phengitic muscovite + chlorite + dolomite + sphene + rutile. The ratio Fe/(Fe + Mg) in dolomite, muscovite (phengite), and chlorite decreases consistently towards the orebodies. Neither bulk chemistry (except for Na2O) nor oxygen isotopic ratio shows consistently systematic lateral changes within the alteration halo. Quartz from the stringer zone, from lenses in massive ore, and from ore-horizon chert all have a very narrow δ18O range of +9.0 to +11.3‰. The δ18O of the QFP is +9.3 to +9.4‰, regardless of the degree of alteration.The temperature of ore formation is estimated to have been around 300 °C based on the paragonite–muscovite geothermometer and the carbonate geothermometer. The δ18O value of the ore-forming solution at 300 °C would have been between +2.1 and +4.4‰, which is similar to that of the Kuroko deposits.

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