Matches in SemOpenAlex for { <https://semopenalex.org/work/W2920454975> ?p ?o ?g. }
- W2920454975 endingPage "790" @default.
- W2920454975 startingPage "755" @default.
- W2920454975 abstract "Abstract We examine REE (Rare-Earth Element) and isotopic (Sr–Hf–Nd–Pb) signatures in OIB (Ocean Island Basalts) as a function of lithospheric thickness and show that the data can be divided into thin- (<12 Ma) and thick-plate (>12 Ma) sub-sets. Comparison to geophysically constrained thermal plate models indicates that the demarcation age (∼12 Ma) corresponds to a lithospheric thickness of about 50 km. Thick-plate OIB show incompatible element and isotopic enrichments, whereas thin-plate lavas show MORB-like or slightly enriched values. We argue that enriched signatures in thick-plate OIB originate from low-degree melting at depths below the dry solidus, while depleted signatures in MORB and thin-plate OIB are indicative of higher-degree melting. We tested quantitative explanations of REE systematics using melting models for homogeneous fertile peridotite. Using experimental partition coefficients for major upper mantle minerals, our equilibrium melting models are not able to explain the data. However, using a new grain-scale disequilibrium melting model for the same homogeneous lithology the data can be explained. Disequilibrium models are able to explain the data by reducing the amount of incompatible element partitioning into low degree melts. To explore new levels of detail in disequilibrium phenomena, we employ the Monte-Carlo Potts model to characterize the textural evolution of a microstructure undergoing coarsening and phase transformation processes simultaneous with the diffusive partitioning of trace elements among solid phases and melt in decompressing mantle. We further employ inverse methods to study the thermochemical properties required for models to explain the OIB data. Both data and theory show that OIB erupted on spreading ridges contain signatures close to MORB values, although E-MORB provides the best fit. This indicates that MORB and OIB are produced by compositionally indistinguishable sources, although the isotopic data indicate that the source is heterogeneous. Also, a posteriori distributions are found for the temperature of the thermomechanical lithosphere-asthenosphere boundary (TLAB), the temperature in the source of OIB (Tp, oib) and the extent of equilibrium during melting (i.e. grain size). TLAB has been constrained to 1200–1300°C and Tp, oib is constrained to be <1400°C. However, we consider the constraints on Tp, oib as a description of all OIB to be provisional, because it is a statistical inference from the global dataset. Exceptional islands or island groups may exist, such as the classical ‘hotspots’ (Hawaii, Reunion, etc) and these islands may originate from hot sources. On the other hand, by the same statistical arguments their origins may be anomalously hydrated or enriched instead. Mean grain size in the source of OIB is about 1–5 mm, although this is also provisional due to a strong dependence on knowledge of partition coefficients, ascent rate and the melting function. We also perform an inversion in which partition coefficients were allowed to vary from their experimental values. In these inversions TLAB and Tp, oib are unchanged, but realizations close to equilibrium can be found when partition coefficients differ substantially from their experimental values. We also investigated bulk compositions in the source of OIB constrained by our inverse models. Corrections for crystallization effects provided ambiguous confirmations of previously proposed mantle compositions, with depleted mantle providing the poorest fits. We did not include isotopes in our models, but we briefly evaluate the lithospheric thickness effect on isotopes. Although REE data do not require a lithologically heterogeneous source, isotopes indicate that a minor enriched component disproportionately contributes to thick-plate OIB, but is diluted by high-degree melting in the generation of thin-plate OIB and MORB." @default.
- W2920454975 created "2019-03-11" @default.
- W2920454975 creator A5023489798 @default.
- W2920454975 creator A5074536926 @default.
- W2920454975 date "2019-03-02" @default.
- W2920454975 modified "2023-10-17" @default.
- W2920454975 title "Chemical Disequilibria, Lithospheric Thickness, and the Source of Ocean Island Basalts" @default.
- W2920454975 cites W152113062 @default.
- W2920454975 cites W1564196663 @default.
- W2920454975 cites W1597277273 @default.
- W2920454975 cites W1828329906 @default.
- W2920454975 cites W1941456882 @default.
- W2920454975 cites W1955979307 @default.
- W2920454975 cites W1965806071 @default.
- W2920454975 cites W1967371674 @default.
- W2920454975 cites W1968103236 @default.
- W2920454975 cites W1968565013 @default.
- W2920454975 cites W1975106767 @default.
- W2920454975 cites W1976586737 @default.
- W2920454975 cites W1977202349 @default.
- W2920454975 cites W1979102269 @default.
- W2920454975 cites W1979981614 @default.
- W2920454975 cites W1980308835 @default.
- W2920454975 cites W1985812434 @default.
- W2920454975 cites W1986306336 @default.
- W2920454975 cites W1988520903 @default.
- W2920454975 cites W1990740187 @default.
- W2920454975 cites W1998709443 @default.
- W2920454975 cites W1999950177 @default.
- W2920454975 cites W2003707441 @default.
- W2920454975 cites W2005422429 @default.
- W2920454975 cites W2005739263 @default.
- W2920454975 cites W2007433465 @default.
- W2920454975 cites W2011607179 @default.
- W2920454975 cites W2012300723 @default.
- W2920454975 cites W2016690871 @default.
- W2920454975 cites W2020383655 @default.
- W2920454975 cites W2022364310 @default.
- W2920454975 cites W2027453112 @default.
- W2920454975 cites W2028377358 @default.
- W2920454975 cites W2031894158 @default.
- W2920454975 cites W2033871657 @default.
- W2920454975 cites W2042445838 @default.
- W2920454975 cites W2042791044 @default.
- W2920454975 cites W2043676912 @default.
- W2920454975 cites W2043821182 @default.
- W2920454975 cites W2049044264 @default.
- W2920454975 cites W2049755807 @default.
- W2920454975 cites W2052097819 @default.
- W2920454975 cites W2053278035 @default.
- W2920454975 cites W2054757994 @default.
- W2920454975 cites W2059517119 @default.
- W2920454975 cites W2059750176 @default.
- W2920454975 cites W2060635442 @default.
- W2920454975 cites W2062471756 @default.
- W2920454975 cites W2062687883 @default.
- W2920454975 cites W2062841099 @default.
- W2920454975 cites W2064958765 @default.
- W2920454975 cites W2066410043 @default.
- W2920454975 cites W2067336738 @default.
- W2920454975 cites W2070590123 @default.
- W2920454975 cites W2072900443 @default.
- W2920454975 cites W2075143646 @default.
- W2920454975 cites W2075816964 @default.
- W2920454975 cites W2076195471 @default.
- W2920454975 cites W2076314280 @default.
- W2920454975 cites W2082070401 @default.
- W2920454975 cites W2082596926 @default.
- W2920454975 cites W2083784240 @default.
- W2920454975 cites W2091898245 @default.
- W2920454975 cites W2093630957 @default.
- W2920454975 cites W2102234201 @default.
- W2920454975 cites W2103507727 @default.
- W2920454975 cites W2108298625 @default.
- W2920454975 cites W2110893975 @default.
- W2920454975 cites W2116886881 @default.
- W2920454975 cites W2122777773 @default.
- W2920454975 cites W2125612064 @default.
- W2920454975 cites W2125654971 @default.
- W2920454975 cites W2129333755 @default.
- W2920454975 cites W2134226415 @default.
- W2920454975 cites W213548141 @default.
- W2920454975 cites W2136718826 @default.
- W2920454975 cites W2136892820 @default.
- W2920454975 cites W2137119378 @default.
- W2920454975 cites W2138522501 @default.
- W2920454975 cites W2140036873 @default.
- W2920454975 cites W2141858059 @default.
- W2920454975 cites W2143830780 @default.
- W2920454975 cites W2147703958 @default.
- W2920454975 cites W2148501813 @default.
- W2920454975 cites W2148876776 @default.
- W2920454975 cites W2155747026 @default.
- W2920454975 cites W2159012312 @default.
- W2920454975 cites W2195087649 @default.
- W2920454975 cites W2324661783 @default.
- W2920454975 cites W2329970122 @default.
- W2920454975 cites W2530248222 @default.