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Geochronological and geochemical signatures of the granitic rocks emplaced at the north‐eastern fringe of the Eastern Dharwar Craton, South India: Implications for late Archean crustal growth
Author(s) -
Mukherjee Sneha,
Ghosh Gautam,
Das Kaushik,
Bose Sankar,
Hayasaka Yasutaka
Publication year - 2017
Publication title -
geological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.721
H-Index - 54
eISSN - 1099-1034
pISSN - 0072-1050
DOI - 10.1002/gj.3007
Subject(s) - geology , dharwar craton , zircon , geochemistry , craton , archean , lithophile , petrogenesis , subduction , magma , crust , volcanic rock , fractional crystallization (geology) , partial melting , petrology , volcano , tectonics , mantle (geology) , paleontology
Geochemical and zircon U–Pb age data on granites of the Chitrial area, situated at the NE part of the Eastern Dharwar Craton, are presented to elucidate their petrogenesis, time(s) of emplacement, and role in crust formation. Based on field and geochemical characters, these granites are classified as alkali feldspar/monzo‐granite. Whole‐rock data of selected samples show evolved calc‐alkaline and peraluminous characters with high SiO 2 , K 2 O, large‐ion lithophile element, and light rare earth elements (LREE), depleted heavy rare earth elements (HREE) and strongly negative Eu anomaly. One sample shows slightly different character with low SiO 2 , enriched light rare earth elements, and depleted heavy rare earth elements without Eu anomaly. Geochemical analyses suggest that the rocks are S‐type granite with syn‐collisional and volcanic arc signatures. These granites define a coherent trend favouring low pressure crystallization of the magma. U–Pb zircon data show that the crystallization ages of the granites vary within 2514 ± 10 to 2525 ± 24 Ma. The geodynamic evolution of the Eastern Dharwar Craton is discussed wherein subduction and deep burial of sediment is envisaged to cause partial melting and granite genesis in the craton.