U-Pb and Hf isotope study of detrital zircon and Cr-spinel in the Banavara quartzite and implications for the evolution of the Dharwar Craton, south India
| Autor: | Argyrios Kapsiotis, J. N. Goswami, B. Maibam, Elena Belousova, Davide Lenaz, Jasper Berndt, Monica Wangjam, Stephen F. Foley |
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| Přispěvatelé: | Maibam, Bidyananda, Lenaz, Davide, Foley, Stephen, Berndt, Jasper, Belousova, Elena, Wangjam, Monica, Goswami, Jitendra N., Kapsiotis, Argyrios |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Provenance
010504 meteorology & atmospheric sciences Archean Metamorphic rock Geochemistry geochronology Metamorphism Geology Provenance X-ray refinement Cr-spinel zircon geochronology Dharwar craton zircon X-ray refinement 010502 geochemistry & geophysics 01 natural sciences Cr-spinel Dharwar Craton Ultramafic rock Geochronology Dharwar craton 0105 earth and related environmental sciences Zircon |
| Popis: | The Sargur Group has been considered to be the oldest group (>3.0 Ga) in the Archaean sequence of the Dharwar Craton in south India, whereas the rocks of the Dharwar Supergroup are younger (between 3.0 and 2.55 Ga). The supracrustal units of the Sargur Group were deposited during the Archaean period. The Banavara quartzite forms part of the supracrustal Sargur Group and contains significant amounts of chromian spinel (Cr-spinel). Here, U–Pb and Hf isotopes of detrital zircons are integrated with compositional data and X-ray refinement parameters for Cr-spinels to decipher the provenance of the metasediments. Zircons show an age spectrum from 3.15 to 2.50 Ga, and juvenile Hf isotopic compositions (ϵHf = +0.8 to +6.4) with model ages between 3.3 and 3.0 Ga. Major- and trace-element contents of the Cr-spinels do not resemble those in the Sargur ultramafic rocks, but resemble well-characterized Archaean anorthosite-hosted chromites. Cr-spinel trace-element signatures indicate that they have undergone secondary alteration or metamorphism. X-ray refinement parameters for the Cr-spinels also resemble the anorthosite-hosted chromites. We conclude that the detrital minerals were probably derived from gneissic and anorthositic rocks of the Western Dharwar Craton, and that the Sargur Group sequences have experienced a younger (2.5 Ga) metamorphic overprint. |
| Databáze: | OpenAIRE |
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