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• W925608141 endingPage "163" @default.
• W925608141 startingPage "141" @default.
• W925608141 abstract "In this study, the U isotope composition, n((238)U)/n((235)U), of major components of the upper continental crust, including granitic rocks of different age and post-Archaean shales, as well as that of rivers (the major U source to the oceans) was investigated. Furthermore, U isotope fractionation during the removal of U at mid-ocean ridges, an important sink for U from the oceans, was investigated by the analyses of hydrothermal water samples (including low- and high-temperature fluids), low-temperature altered basalts and calcium carbonate veins. All analysed rock samples from the continental crust fall into a limited range of δ(238)U between -0.45 and -0.21 ‰ (relative to NBL CRM 112-A), with an average of -0.30 ± 0.15 ‰ (2 SD, N = 11). Despite differences in catchment lithologies, all major rivers define a relatively narrow range between -0.31 and -0.13 ‰, with a weighted mean isotope composition of -0.27 ‰, which is indistinguishable from the estimate for the upper continental crust (-0.30 ‰). Only some tributary rivers from the Swiss Alps display a slightly larger range in δ(238)U (-0.29 to +0.01 ‰) and lower U concentrations (0.87-3.08 nmol/kg) compared to the investigated major rivers (5.19-11.69 nmol/kg). These findings indicate that only minor net U isotope fractionation occurs during weathering and transport of material from the continental crust to the oceans. Altered basalts display moderately enriched U concentrations (by a factor of 3-18) compared to those typically observed for normal mid-ocean ridge basalts. These, and carbonate veins within altered basalts, show large U isotope fractionation towards both heavy and light U isotope compositions (ranging from -0.63 to +0.27 ‰). Hydrothermal water samples display low U concentrations (0.3-1 nmol/kg) and only limited variations in their U isotope composition (-0.43 ± 0.25 ‰) around the seawater value. Nevertheless, two of the investigated fluids display significantly lower δ(238)U (-0.55 and -0.59 ‰) than seawater (-0.38 ‰). These findings, together with the heavier U isotope composition observed for some altered basalts and carbonate veins support a model, in which redox processes mostly drive U isotope fractionation. This may result in a slightly heavier U isotope composition of U that is removed from seawater during hydrothermal seafloor alteration compared to that of seawater. Using the estimated isotope compositions of rivers and all U sinks from the ocean (of this study and the literature) for modelling of the isotopic U mass balance, this gives reasonable results for recent estimates of the oceanic U budget. It furthermore provides additional constraints on the relative size of the diverse U sinks and respective net isotope fractionation during U removal." @default.
• W925608141 created "2016-06-24" @default.
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• W925608141 date "2015-06-18" @default.
• W925608141 modified "2023-10-16" @default.
• W925608141 title "²³⁸U/²³⁵U isotope ratios of crustal material, rivers and products of hydrothermal alteration: new insights on the oceanic U isotope mass balance" @default.
• W925608141 cites W1963985336 @default.
• W925608141 cites W1964319225 @default.
• W925608141 cites W1966264684 @default.
• W925608141 cites W1967847114 @default.
• W925608141 cites W1969092428 @default.
• W925608141 cites W1969859799 @default.
• W925608141 cites W1969913793 @default.
• W925608141 cites W1972083835 @default.
• W925608141 cites W1974653767 @default.
• W925608141 cites W1979566720 @default.
• W925608141 cites W1980523565 @default.
• W925608141 cites W1984980690 @default.
• W925608141 cites W1987792566 @default.
• W925608141 cites W1989182282 @default.
• W925608141 cites W1990116280 @default.
• W925608141 cites W1991442438 @default.
• W925608141 cites W1992316766 @default.
• W925608141 cites W1998290559 @default.
• W925608141 cites W1998734655 @default.
• W925608141 cites W1999514717 @default.
• W925608141 cites W2008670387 @default.
• W925608141 cites W2008880971 @default.
• W925608141 cites W2013885099 @default.
• W925608141 cites W2015194455 @default.
• W925608141 cites W2022672057 @default.
• W925608141 cites W2026129668 @default.
• W925608141 cites W2026367284 @default.
• W925608141 cites W2026658965 @default.
• W925608141 cites W2026723150 @default.
• W925608141 cites W2027774423 @default.
• W925608141 cites W2028487454 @default.
• W925608141 cites W2043333595 @default.
• W925608141 cites W2044633001 @default.
• W925608141 cites W2046219145 @default.
• W925608141 cites W2050775407 @default.
• W925608141 cites W2052812669 @default.
• W925608141 cites W2054842898 @default.
• W925608141 cites W2055853410 @default.
• W925608141 cites W2055862951 @default.
• W925608141 cites W2056255377 @default.
• W925608141 cites W2056852542 @default.
• W925608141 cites W2058484309 @default.
• W925608141 cites W2059146037 @default.
• W925608141 cites W2060274344 @default.
• W925608141 cites W2063659084 @default.
• W925608141 cites W2063942616 @default.
• W925608141 cites W2067809411 @default.
• W925608141 cites W2068527782 @default.
• W925608141 cites W2069102547 @default.
• W925608141 cites W2069488139 @default.
• W925608141 cites W2070219421 @default.
• W925608141 cites W2071922154 @default.
• W925608141 cites W2074326614 @default.
• W925608141 cites W2077959484 @default.
• W925608141 cites W2078217501 @default.
• W925608141 cites W2085562887 @default.
• W925608141 cites W2087142813 @default.
• W925608141 cites W2087272845 @default.
• W925608141 cites W2089124355 @default.
• W925608141 cites W2091065826 @default.
• W925608141 cites W2100678868 @default.
• W925608141 cites W2107474811 @default.
• W925608141 cites W2111572490 @default.
• W925608141 cites W2116568181 @default.
• W925608141 cites W2119438235 @default.
• W925608141 cites W2124693898 @default.
• W925608141 cites W2139581884 @default.
• W925608141 cites W2154620771 @default.
• W925608141 cites W2155885199 @default.
• W925608141 cites W2155927888 @default.
• W925608141 cites W2156107051 @default.
• W925608141 cites W2157677644 @default.
• W925608141 cites W2157681159 @default.
• W925608141 cites W2170900766 @default.
• W925608141 cites W2222469210 @default.
• W925608141 cites W2783162205 @default.
• W925608141 cites W2916340484 @default.
• W925608141 doi "https://doi.org/10.1080/10256016.2015.1047449" @default.
• W925608141 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/26085006" @default.
• W925608141 hasPublicationYear "2015" @default.
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