Matches in SemOpenAlex for { <https://semopenalex.org/work/W2034333209> ?p ?o ?g. }
- W2034333209 endingPage "102" @default.
- W2034333209 startingPage "76" @default.
- W2034333209 abstract "A zircon ‘microvein’ composed of several hundred crystals occurs in peralkaline granitic gneiss of western Ethiopian Precambrians. U–Pb ages and trace element (U, Th, Hf, Y, REE, P, Ca, Al, Fe, and Mn) abundances of the ‘microvein’ and host granitic gneiss zircon were determined using a sensitive high mass resolution ion microprobe (SHRIMP) and electron probe microanalyzer (EPMA). Back-scattered electron (BSE) imaging of the ‘microvein’ zircon and host granite zircon, hereafter referred to as Type-I and Type-II zircon, respectively, reveal prevalent low and high mean atomic number contrast domains within individual crystals. Ubiquitous fluorite microinclusions in bright BSE domains of Type-I and less commonly, Type-II zircon suggest an early formation of fluorite that buffers F activity, causing zircon supersaturation and precipitation from a late-magmatic melt/fluid-enriched in high field strength elements (HFSEs) including Zr. The textural make up of the host peralkaline granitic gneiss and internal structural features of Type-I and Type-II zircon indicate that dark-grey BSE domains were formed by dissolution–reprecipitation owing to fluid infiltration and interaction with the primary zircon crystals. The bright and dark-grey BSE domains in Type-I zircon yield U–Pb ages of 779 ± 69 Ma and 780 ± 35 Ma, and similar domains in Type-II zircon dated at 778 ± 49 Ma and 780 ± 31 Ma, respectively. The primary and recrystallized domains in both zircon types have indistinguishable ages, suggesting initial crystallization shortly followed by fluid-driven alteration. The ages are identical, within analytical uncertainties, to the 776 ± 12 Ma zircon U–Pb emplacement age of a protolith of a leucocratic granitic gneiss determined from a different sample. Hence, zircon crystals forming ‘microvein’ and aggregate structures, the relatively high Th/U ratios (reaching up to 1.5) in the primary domains, high LREE/HREE, and the formation of Type-I and Type-II zircon during emplacement support a late-magmatic–hydrothermal origin. Extensive alteration of the host rock, recrystallization of young and non-metamict zircon corroborate the infiltration of orthomagmatic or hydrothermal fluids containing fluorides as a major constituent, which expelled a considerable amount of trace elements, namely, Hf, U, Th, Y, and the REEs, from the recrystallized domains of Type-I and Type-II zircon. The trace element depleted recrystallized domains characteristically contain microfractures apparently caused by differential volume expansion of the U and Th enriched primary domains or volume change during cation exchange reactions, and anomalously high Th/U ratios (∼ 0.5 to 1.0). Furthermore, the ca. 780–776 Ma emplacement age of the protolith of the peralkaline granitic gneiss and late-stage orthomagmatic or hydrothermal activity shed light on the occurrence of older anorogenic granitoid magmatism and associated structures in western Ethiopian Precambrian terranes." @default.
- W2034333209 created "2016-06-24" @default.
- W2034333209 creator A5025443552 @default.
- W2034333209 creator A5026788147 @default.
- W2034333209 creator A5074836720 @default.
- W2034333209 creator A5086861196 @default.
- W2034333209 date "2007-07-01" @default.
- W2034333209 modified "2023-09-27" @default.
- W2034333209 title "Zircon ‘microvein’ in peralkaline granitic gneiss, western Ethiopia: Origin, SHRIMP U–Pb geochronology and trace element investigations" @default.
- W2034333209 cites W1521262137 @default.
- W2034333209 cites W1615451124 @default.
- W2034333209 cites W1869545340 @default.
- W2034333209 cites W1946565071 @default.
- W2034333209 cites W1968013432 @default.
- W2034333209 cites W1968926757 @default.
- W2034333209 cites W1971363808 @default.
- W2034333209 cites W1977650828 @default.
- W2034333209 cites W1979442888 @default.
- W2034333209 cites W1979790829 @default.
- W2034333209 cites W1980513018 @default.
- W2034333209 cites W1984719232 @default.
- W2034333209 cites W1986560096 @default.
- W2034333209 cites W1988801157 @default.
- W2034333209 cites W1995446222 @default.
- W2034333209 cites W1997040345 @default.
- W2034333209 cites W1999166202 @default.
- W2034333209 cites W1999750072 @default.
- W2034333209 cites W2002139305 @default.
- W2034333209 cites W2002831664 @default.
- W2034333209 cites W2002930027 @default.
- W2034333209 cites W2007935173 @default.
- W2034333209 cites W2008056984 @default.
- W2034333209 cites W2008072085 @default.
- W2034333209 cites W2008908076 @default.
- W2034333209 cites W2010781943 @default.
- W2034333209 cites W2017804925 @default.
- W2034333209 cites W2019486616 @default.
- W2034333209 cites W2020139762 @default.
- W2034333209 cites W2020881157 @default.
- W2034333209 cites W2021370058 @default.
- W2034333209 cites W2022295718 @default.
- W2034333209 cites W2022375592 @default.
- W2034333209 cites W2022737532 @default.
- W2034333209 cites W2028625569 @default.
- W2034333209 cites W2029602159 @default.
- W2034333209 cites W2030517190 @default.
- W2034333209 cites W2037378550 @default.
- W2034333209 cites W2037588390 @default.
- W2034333209 cites W2038019149 @default.
- W2034333209 cites W2041007499 @default.
- W2034333209 cites W2042803182 @default.
- W2034333209 cites W2045038743 @default.
- W2034333209 cites W2046961523 @default.
- W2034333209 cites W2048731492 @default.
- W2034333209 cites W2055980863 @default.
- W2034333209 cites W2059642938 @default.
- W2034333209 cites W2067336135 @default.
- W2034333209 cites W2068372312 @default.
- W2034333209 cites W2069101381 @default.
- W2034333209 cites W2081562722 @default.
- W2034333209 cites W2081828501 @default.
- W2034333209 cites W2081995251 @default.
- W2034333209 cites W2089423835 @default.
- W2034333209 cites W2096312949 @default.
- W2034333209 cites W2117310136 @default.
- W2034333209 cites W2127039475 @default.
- W2034333209 cites W2134266912 @default.
- W2034333209 cites W2145467034 @default.
- W2034333209 cites W2146133038 @default.
- W2034333209 cites W2161090395 @default.
- W2034333209 cites W2161738623 @default.
- W2034333209 cites W2167356922 @default.
- W2034333209 cites W2172127771 @default.
- W2034333209 cites W2174216460 @default.
- W2034333209 cites W2385435147 @default.
- W2034333209 doi "https://doi.org/10.1016/j.chemgeo.2007.03.014" @default.
- W2034333209 hasPublicationYear "2007" @default.
- W2034333209 type Work @default.
- W2034333209 sameAs 2034333209 @default.
- W2034333209 citedByCount "27" @default.
- W2034333209 countsByYear W20343332092012 @default.
- W2034333209 countsByYear W20343332092013 @default.
- W2034333209 countsByYear W20343332092014 @default.
- W2034333209 countsByYear W20343332092015 @default.
- W2034333209 countsByYear W20343332092016 @default.
- W2034333209 countsByYear W20343332092018 @default.
- W2034333209 countsByYear W20343332092019 @default.
- W2034333209 countsByYear W20343332092020 @default.
- W2034333209 countsByYear W20343332092021 @default.
- W2034333209 countsByYear W20343332092022 @default.
- W2034333209 countsByYear W20343332092023 @default.
- W2034333209 crossrefType "journal-article" @default.
- W2034333209 hasAuthorship W2034333209A5025443552 @default.
- W2034333209 hasAuthorship W2034333209A5026788147 @default.
- W2034333209 hasAuthorship W2034333209A5074836720 @default.
- W2034333209 hasAuthorship W2034333209A5086861196 @default.
- W2034333209 hasConcept C11872896 @default.
- W2034333209 hasConcept C120806208 @default.