FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2901866369> ?p ?o ?g. }

• W2901866369 abstract "During solidification of magma chambers as systems closed to chemical exchange with environs, the residual siliceous melt may follow a trend of rising, constant, or decreasing oxidation state, relative to reference buffers such as nickel + nickel oxide (NNO) or fayalite + magnetite + quartz. Titanomagnetite–hemoilmenite thermometry and oxybarometry on quenched volcanic suites yield temperature versus oxygen fugacity arrays of varied positive and negative slopes, the validity of which has been disputed for several years. We resolve the controversy by introducing a new recorder of magmatic redox evolution employing temperature- and redox-sensitive trace-element abundances in zircon. The zircon/melt partition coefficients of cerium and uranium vary oppositely in response to variation of magma redox state, but vary in tandem as temperature varies. Plots of U/Pr versus Ce4+/Ce3+ in zircon provide a robust test for change in oxidation state of the melt during zircon crystallisation from cooling magma, and the plots discriminate thermally induced from redox-induced variation of Ce4+/Ce3+ in zircon. Temperature-dependent lattice strain causes Ce4+/Ce3+ in zircon to increase strongly as zircon crystallises from cooling magma at constant Ce4+/Ce3+ ratio in the melt. We examine 19 zircon populations from igneous complexes in varied tectonic settings. Variation of zircon Ce4+/Ce3+ due to minor variation in melt oxidation state during crystallisation is resolvable in 11 cases but very subordinate to temperature dependence. In many zircon populations described in published literature, there is no resolvable change in redox state of the melt during tenfold variation of Ce4+/Ce3+ in zircons. Varied magmatic redox trends indicated by different slopes on plots of zircon U/Pr versus Ce4+/Ce3+ are corroborated by Fe–Ti-oxide-based T–ƒO2 trends of correspondingly varied slopes. Zircon and Fe–Ti-oxide compositions agree that exceptionally, H2O-rich arc magmas tend to follow a trend of rising oxidation state of the melt during late stages of fluid-saturated magmatic differentiation at upper-crustal pressures. We suggest that H2 and/or SO3 and/or Fe2+ loss from the melt to segregating fluid is largely responsible. Conversely, zircon and Fe–Ti-oxide compositions agree in indicating that H2O-poor magmas tend to follow a T–ƒO2 trend of decreasing oxidation state of the melt during late stages of magmatic differentiation at upper-crustal pressures, because the precipitating mineral assemblage has higher Fe3+/Fe2+ than coexisting rhyolitic melt. We present new evidence showing that the Fe–Ti-oxide oxybarometer calibration by Ghiorso and Evans (Am J Sci 308(9):957–1039, 2008) retrieves experimentally imposed values of ƒO2 in laboratory syntheses of Fe–Ti-oxide pairs to a precision of ± 0.2 log unit, over a large experimental temperature range, without systematic bias up to at least log ƒO2 ≈ NNO + 4.4. Their titanomagnetite–hemoilmenite geothermometer calibration has large systematic errors in application to Ti-poor oxides that precipitate from very oxidised magmas. A key outcome is validation of Fe–Ti-oxide-based values of melt TiO2 activity for use in Ti-in-zircon thermometry and Ti-in-quartz thermobarometry." @default.
• W2901866369 created "2018-11-29" @default.
• W2901866369 creator A5028967721 @default.
• W2901866369 creator A5035843659 @default.
• W2901866369 creator A5085685423 @default.
• W2901866369 date "2018-11-23" @default.
• W2901866369 modified "2023-10-18" @default.
• W2901866369 title "Divergent T–ƒO2 paths during crystallisation of H2O-rich and H2O-poor magmas as recorded by Ce and U in zircon, with implications for TitaniQ and TitaniZ geothermometry" @default.
• W2901866369 cites W1220526507 @default.
• W2901866369 cites W1484243411 @default.
• W2901866369 cites W1964097615 @default.
• W2901866369 cites W1964337024 @default.
• W2901866369 cites W1969375798 @default.
• W2901866369 cites W1975384952 @default.
• W2901866369 cites W1978647936 @default.
• W2901866369 cites W1981226676 @default.
• W2901866369 cites W1984215952 @default.
• W2901866369 cites W1988339658 @default.
• W2901866369 cites W1991492676 @default.
• W2901866369 cites W1994057479 @default.
• W2901866369 cites W1994876715 @default.
• W2901866369 cites W1997120104 @default.
• W2901866369 cites W1999075746 @default.
• W2901866369 cites W2001764658 @default.
• W2901866369 cites W2002403064 @default.
• W2901866369 cites W2002945718 @default.
• W2901866369 cites W2004828174 @default.
• W2901866369 cites W2005616801 @default.
• W2901866369 cites W2019693008 @default.
• W2901866369 cites W2020316016 @default.
• W2901866369 cites W2023491467 @default.
• W2901866369 cites W2026700549 @default.
• W2901866369 cites W2028048720 @default.
• W2901866369 cites W2028905891 @default.
• W2901866369 cites W2029157156 @default.
• W2901866369 cites W2031928338 @default.
• W2901866369 cites W2034767561 @default.
• W2901866369 cites W2035383650 @default.
• W2901866369 cites W2036918177 @default.
• W2901866369 cites W2036966012 @default.
• W2901866369 cites W2040120198 @default.
• W2901866369 cites W2040549377 @default.
• W2901866369 cites W2041389048 @default.
• W2901866369 cites W2042692134 @default.
• W2901866369 cites W2043760612 @default.
• W2901866369 cites W2044975996 @default.
• W2901866369 cites W2046345979 @default.
• W2901866369 cites W2046961523 @default.
• W2901866369 cites W2052332245 @default.
• W2901866369 cites W2053051490 @default.
• W2901866369 cites W2054653182 @default.
• W2901866369 cites W2056910670 @default.
• W2901866369 cites W2062650796 @default.
• W2901866369 cites W2063711039 @default.
• W2901866369 cites W2064110430 @default.
• W2901866369 cites W2067333889 @default.
• W2901866369 cites W2071329652 @default.
• W2901866369 cites W2073005734 @default.
• W2901866369 cites W2073889251 @default.
• W2901866369 cites W2074293173 @default.
• W2901866369 cites W2075031500 @default.
• W2901866369 cites W2076321735 @default.
• W2901866369 cites W2076587292 @default.
• W2901866369 cites W2078366028 @default.
• W2901866369 cites W2078580374 @default.
• W2901866369 cites W2078601513 @default.
• W2901866369 cites W2080539747 @default.
• W2901866369 cites W2082437012 @default.
• W2901866369 cites W2085438407 @default.
• W2901866369 cites W2090711726 @default.
• W2901866369 cites W2092678733 @default.
• W2901866369 cites W2095298264 @default.
• W2901866369 cites W2096680403 @default.
• W2901866369 cites W2097932174 @default.
• W2901866369 cites W2098301317 @default.
• W2901866369 cites W2100772541 @default.
• W2901866369 cites W2116080110 @default.
• W2901866369 cites W2119949381 @default.
• W2901866369 cites W2122878872 @default.
• W2901866369 cites W2128225906 @default.
• W2901866369 cites W2140657107 @default.
• W2901866369 cites W2147064838 @default.
• W2901866369 cites W2151760199 @default.
• W2901866369 cites W2154727657 @default.
• W2901866369 cites W2155146104 @default.
• W2901866369 cites W2162359721 @default.
• W2901866369 cites W2165599725 @default.
• W2901866369 cites W2167590372 @default.
• W2901866369 cites W2170357552 @default.
• W2901866369 cites W2277995190 @default.
• W2901866369 cites W2306321048 @default.
• W2901866369 cites W2310657756 @default.
• W2901866369 cites W2318881081 @default.
• W2901866369 cites W2319043448 @default.
• W2901866369 cites W2319555640 @default.
• W2901866369 cites W2321796051 @default.
• W2901866369 cites W2334964922 @default.
• W2901866369 cites W2335771695 @default.
• W2901866369 cites W2463058753 @default.
• W2901866369 cites W2515657422 @default.

• next