Browsing by Author "Valley J.W."
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Browsing by Author "Valley J.W."
Now showing items 1-20 of 24
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Valley J.W.; Lackey J.S.; Cavosie A.J.; Clechenko C.C.; Spicuzza M.J.; Basei M.A.S.; Bindeman I.N.; Ferreira V.P.; Sial A.N.; King E.M.; Peck W.H.; Sinha A.K.; Wei C.S. (2005)Analysis of δ18O in igneous zircons of known age traces the evolution of intracrustal recycling and crust-mantle interaction through time. This record is especially sensitive because oxygen isotope ratios of igneous rocks ...
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Cole D.R.; Horita J.; Polyakov V.B.; Valley J.W.; Spicuzza M.J.; Coffey D.W. (2004)Oxygen isotope fractionations have been determined between magnetite and water from 300 to 800°C and pressures between 10 and 215MPa. We selected three reaction pathways to investigate fractionation: (a) reaction of ...
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Bindeman I.N.; Vinogradov V.I.; Valley J.W.; Wooden J.L.; Natal'in B.A. (2002)We used an ion microprobe (SHRIMP-RG) for U-Pb dating of individual zircons in high-grade metamorphic basements of the felsic Sredinny and mafic Ganal Massifs in Kamchatka. Thirty percent of zircons from paragneisses of ...
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Cavosie A.J.; Valley J.W.; Wilde S.A. (2006)The origins of >3900 Ma detrital zircons from Western Australia are controversial, in part due to their complexity and long geologic histories. Conflicting interpretations for the genesis of these zircons propose magmatic, ...
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Fortier S.M.; Cole D.R.; Wesolowski D.J.; Riciputi L.R.; Paterson B.A.; Valley J.W.; Horita J. (1995)A Cameca 4f ion microprobe has been used in conjunction with laser and conventional analytical techniques to measure the oxygen isotope fractionation between magnetite and water at 350°C. A set of experiments in which large ...
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Valley J.W.; Bindeman I.N.; Peck W.H. (2003)New empirical calibrations for the fractionation of oxygen isotopes among zircon, almandine-rich garnet, titanite, and quartz are combined with experimental values for quartz-grossular. The resulting A-coefficients (‰K 2) ...
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King E.M.; Valley J.W.; Davis D.W.; Kowallis B.J. (2001)Measurements of oxygen isotope fractionations between coexisting igneous titanite (Ttn) and zircon (Zrc) have been used to formulate a self-consistent, empirical calibration of equilibrium oxygen isotope partitioning: 1000 ...
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Schulze D.J.; Harte B.; Valley J.W.; Channer D.M.DeR. (2004)Cathodoluminescence (CL) imaging of polished sections of a diamond from the Guaniamo region of Venezuela suggests a history of the diamond involving two periods of growth separated by a period of resorption and possibly ...
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Kohn M.J.; Schoeninger M.J.; Valley J.W. (1996)The applicability of rapid and precise laser probe analysis of tooth enamel for δ18O has been verified, and the method has been applied to different modern herbivores in East Africa. Sampling and pretreatment procedures ...
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Reeder R.J.; Valley J.W.; Graham C.M.; Eiler J.M. (1997)A synthetic calcite crystal that exhibits surface-structure-controlled, differential incorporation of a trace element was examined by ion microprobe to determine whether the controls causing differential element incorporation ...
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Utsunomiya S.; Palenik C.S.; Ewing R.C.; Valley J.W.; Cavosie A.J.; Wilde S.A. (2004)We report, for the first time, a direct, atomic-scale characterization of Pb in zircon (4.4 3.1 Ga) from the early Archean Yilgarn craton in Australia using high-resolution HAADF-STEM. Two forms of Pb have been identified: ...
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Edwards K.J.; Valley J.W. (1998)The oxygen isotope ratio of diopside correlates with crystal size in many high grade marbles, permitting the intracrystalline self-diffusion rate of oxygen in diopside to be empirically evaluated.Small (75-300 μm) and large ...
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OXYGEN ISOTOPE GEOCHEMISTRY OF THE AMPHIBOLES: ISOTOPE EFFECTS OF CATION SUBSTITUTIONS IN MINERALS Kohn M.J.; Valley J.W. (1998)The occurrence of coexisting amphiboles in rocks and the likelihood of concurrent isotope closure allows equilibrium oxygen isotope fractionations among the amphiboles to be recovered from natural samples. Oxygen isotope ...
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Kohn M.J.; Valley J.W. (1998)The occurrence of coexisting amphiboles in rocks and the likelihood of concurrent isotope closure allows equilibrium oxygen isotope fractionations among the amphiboles to be recovered from natural samples. Oxygen isotope ...
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Eiler J.M.; Farley K.A.; Stolper E.M.; Valley J.W.; Hauri E.; Craig H.; Hart S.R. (1997)Oxygen isotope ratios are reported for olivine phenocrysts from sixty-seven samples of ocean island basalts (OlBs), mid-ocean ridge basalts (MORBs), and related peridotites, including representatives of the various isotopic ...
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Valley J.W. (2003)Isotopic and trace element analysis of zircons can provide reliable and robust estimates of age, compositions of coexisting minerals and melts, and constraints on the genesis and protoliths of host rocks. Recent technological ...
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Eiler J.M.; Graham C.; Valley J.W. (1997)A large instrumental mass fractionation (IMF) occurs during the measurement of oxygen isotope ratios by secondary ion mass spectrometry and the magnitude of this fractionation can be dependent upon sample chemistry, resulting ...
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Valley J.W. (2001)Determination of accurate temperatures for geological events has been the grail of stable isotope geochemistry since the seminal 1947 paper by Urey. In theory, this should be simple. Calibrated mineral pairs are common, ...
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Spicuzza M.J.; Valley J.W.; Kohn M.J.; Girard J.P.; Fouillac A.M. (1998)We describe a laser fluorination technique specifically for quartz that allows both high-accuracy and high-precision determination of oxygen isotope ratios, regardless of grain size. The rapid heating, defocused beam ...
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Eiler J.M.; Valley J.W.; Graham C.M.; Fournelle J. (2002)We present major and trace-element, oxygen isotope, textural, and structural data for carbonates and related phases in the SNC meteorite ALH84001. These data document the existence of at least two distinct carbonate ...
Now showing items 1-20 of 24