FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2052985280> ?p ?o ?g. }

• W2052985280 endingPage "451" @default.
• W2052985280 startingPage "439" @default.
• W2052985280 abstract "Many of the oldest ∼3.5 Ga komatiites have low Al2O3/TiO2 and depleted HREE, features that are attributed to garnet fractionation at some stage during their formation. It is not known, however, whether this fractionation took place at the time of melting, or well before, perhaps during the crystallization of an early magma ocean. We report here the Hf isotope compositions of four Al-depleted komatiites from the 3.45 Ga Barberton Greenstone Belt in South Africa and six Al-undepleted komatiites from 2.7 to 1.9 Ga belts in Canada and Zimbabwe. We also measured the Hf isotope compositions of five tholeiites from Barberton and two tholeiites from the 1.9 Ga Canadian Belt, to provide information about the composition of ambient Precambrian mantle. All the komatiites have high initial 176Hf/177Hf ratios. All initial ɛHf values are positive, in the range of +2.6 to +7.8. Almost this entire range is also present in the 3.45 Ga Barberton komatiites (+2.6 to +7.3). ɛHf(T) correlates with ɛNd(T) and defines a crude linear array that coincides with compositions of both modern oceanic basalts and of Phanerozoic to Archean juvenile crustal rocks. The composition of Bulk Silicate Earth [J. Blichert-Toft, F. Albarède, Earth Planet. Sci. Lett. 148 (1997) 243–258] plots below this array, at slightly lower ɛHf. To explain the positive initial ɛHf values of 3.45 Ga Barberton komatiites, the source must have had high Lu/Hf. This implies a source enriched in garnet, a result contrary to earlier models in which the low Al2O3/TiO2 and low Lu/Hf of this type of komatiite was thought to be inherited directly from mantle depleted in garnet. The low Al2O3/TiO2 and low Lu/Hf are features of the primary komatiite magmas, not of their mantle source, and result from garnet fractionation during komatiite formation. To explain the bias to high initial ɛHf values of the komatiites and other terrestrial rocks, we consider two alternatives: (a) a reservoir with low Lu/Hf formed very early in Earth history; (b) accepted values for the Hf isotopic composition of Bulk Silicate Earth are inappropriate and the actual composition has higher 176Hf/177Hf and lower 176Lu/177Hf. A problem with the latter interpretation is that the proposed composition lies off the achondrite meteorite isochron, which implies that the Earth has a different age, or accreted from material with composition different from that of meteorites." @default.
• W2052985280 created "2016-06-24" @default.
• W2052985280 creator A5002563422 @default.
• W2052985280 creator A5075189526 @default.
• W2052985280 date "1999-09-01" @default.
• W2052985280 modified "2023-10-18" @default.
• W2052985280 title "Hf isotope compositions of komatiites" @default.
• W2052985280 cites W1587965322 @default.
• W2052985280 cites W1964865374 @default.
• W2052985280 cites W1967349852 @default.
• W2052985280 cites W1973278816 @default.
• W2052985280 cites W1973726990 @default.
• W2052985280 cites W1993449388 @default.
• W2052985280 cites W2009683688 @default.
• W2052985280 cites W2015648501 @default.
• W2052985280 cites W2017286445 @default.
• W2052985280 cites W2018984275 @default.
• W2052985280 cites W2020304604 @default.
• W2052985280 cites W2028191949 @default.
• W2052985280 cites W2028446699 @default.
• W2052985280 cites W2030111153 @default.
• W2052985280 cites W2049135286 @default.
• W2052985280 cites W2059308444 @default.
• W2052985280 cites W2067123129 @default.
• W2052985280 cites W2074212603 @default.
• W2052985280 cites W2074924691 @default.
• W2052985280 cites W2088337974 @default.
• W2052985280 cites W2090206242 @default.
• W2052985280 cites W2119438235 @default.
• W2052985280 cites W2150851598 @default.
• W2052985280 cites W2156985625 @default.
• W2052985280 doi "https://doi.org/10.1016/s0012-821x(99)00151-x" @default.
• W2052985280 hasPublicationYear "1999" @default.
• W2052985280 type Work @default.
• W2052985280 sameAs 2052985280 @default.
• W2052985280 citedByCount "108" @default.
• W2052985280 countsByYear W20529852802012 @default.
• W2052985280 countsByYear W20529852802013 @default.
• W2052985280 countsByYear W20529852802014 @default.
• W2052985280 countsByYear W20529852802015 @default.
• W2052985280 countsByYear W20529852802016 @default.
• W2052985280 countsByYear W20529852802017 @default.
• W2052985280 countsByYear W20529852802018 @default.
• W2052985280 countsByYear W20529852802019 @default.
• W2052985280 countsByYear W20529852802020 @default.
• W2052985280 countsByYear W20529852802021 @default.
• W2052985280 countsByYear W20529852802022 @default.
• W2052985280 countsByYear W20529852802023 @default.
• W2052985280 crossrefType "journal-article" @default.
• W2052985280 hasAuthorship W2052985280A5002563422 @default.
• W2052985280 hasAuthorship W2052985280A5075189526 @default.
• W2052985280 hasConcept C11872896 @default.
• W2052985280 hasConcept C127313418 @default.
• W2052985280 hasConcept C147894010 @default.
• W2052985280 hasConcept C149347711 @default.
• W2052985280 hasConcept C151730666 @default.
• W2052985280 hasConcept C161509811 @default.
• W2052985280 hasConcept C16942324 @default.
• W2052985280 hasConcept C173776410 @default.
• W2052985280 hasConcept C17409809 @default.
• W2052985280 hasConcept C2778849375 @default.
• W2052985280 hasConcept C2779417233 @default.
• W2052985280 hasConcept C2780733770 @default.
• W2052985280 hasConcept C67236022 @default.
• W2052985280 hasConcept C77928131 @default.
• W2052985280 hasConcept C79572550 @default.
• W2052985280 hasConceptScore W2052985280C11872896 @default.
• W2052985280 hasConceptScore W2052985280C127313418 @default.
• W2052985280 hasConceptScore W2052985280C147894010 @default.
• W2052985280 hasConceptScore W2052985280C149347711 @default.
• W2052985280 hasConceptScore W2052985280C151730666 @default.
• W2052985280 hasConceptScore W2052985280C161509811 @default.
• W2052985280 hasConceptScore W2052985280C16942324 @default.
• W2052985280 hasConceptScore W2052985280C173776410 @default.
• W2052985280 hasConceptScore W2052985280C17409809 @default.
• W2052985280 hasConceptScore W2052985280C2778849375 @default.
• W2052985280 hasConceptScore W2052985280C2779417233 @default.
• W2052985280 hasConceptScore W2052985280C2780733770 @default.
• W2052985280 hasConceptScore W2052985280C67236022 @default.
• W2052985280 hasConceptScore W2052985280C77928131 @default.
• W2052985280 hasConceptScore W2052985280C79572550 @default.
• W2052985280 hasIssue "3" @default.
• W2052985280 hasLocation W20529852801 @default.
• W2052985280 hasOpenAccess W2052985280 @default.
• W2052985280 hasPrimaryLocation W20529852801 @default.
• W2052985280 hasRelatedWork W1973212983 @default.
• W2052985280 hasRelatedWork W2025758104 @default.
• W2052985280 hasRelatedWork W2030142526 @default.
• W2052985280 hasRelatedWork W2039380987 @default.
• W2052985280 hasRelatedWork W2052985280 @default.
• W2052985280 hasRelatedWork W2058494426 @default.
• W2052985280 hasRelatedWork W2062769982 @default.
• W2052985280 hasRelatedWork W2081032602 @default.
• W2052985280 hasRelatedWork W2885009804 @default.
• W2052985280 hasRelatedWork W2925357404 @default.
• W2052985280 hasVolume "171" @default.
• W2052985280 isParatext "false" @default.
• W2052985280 isRetracted "false" @default.

• next