Srinivasan, R. ; Naha, K. ; Bhaskar Rao, Y. J. ; Vrevsky, A. B. ; Rybaftov, S. I. ; Golubev, A. I. ; Efimov, M. (1993) Middle to late Archaean geology of the eastern Baltic shield, with a note on its similarity and contrast with the Archaean of Southern India Proceedings of the Indian Academy of Sciences - Earth and Planetary Sciences, 102 (4). pp. 567-585. ISSN 0253-4126
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Official URL: http://www.ias.ac.in/j_archive/epsci/102/4/567-585...
Related URL: http://dx.doi.org/10.1007/BF02871954
Abstract
The middle to late Archaean rocks of Kola and Karelia in the eastern Baltic shield consist of the Infracomplex overlain by the Saamian complex, and the Lopian greenstone belts. The Infracomplex which forms the basement is a polymigmatite, parts of which are at least 3100 Ma old. The Saamian in the central Belomorian region comprises granite gneiss, amphibolite, garnet-kyanite gneiss and high alumina gneisses which belong to the Keret, Hetolombina and Chupa suites. The Lopian greenstone belts ranging in age from 3000 to 2700 Ma are composed of peridotitic, pyroxenitic and basaltic komatiites, tholeiitic basalts, andesites, dacites and rhyolites, together with tuffs, graywackes and iron formations. Whereas there is a dominance of volcanic over sedimentary rocks in the greenstone belts of the Baltic shield, a significant proportion of detrital and chemogenic sedimentary rocks characterizes the Dharwar succession of approximately the same time span in the southern Indian shield. Association of mature and immature detrital sedimentary rocks with bimodal volcanic assemblages points to a back-arc setting for the Dharwar belts. This contrasts with the association of immature sediments with calc-alkaline volcanic rocks in the greenstone belts of the eastern Baltic shield, suggesting an island arc environment there.
Item Type: | Article |
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Source: | Copyright of this article belongs to Indian Academy of Sciences. |
Keywords: | Archaean; Dharwar; Eastern Baltic Shield; Infracomplex; Peninsular Gneiss; Southern India |
ID Code: | 91850 |
Deposited On: | 24 May 2012 14:10 |
Last Modified: | 19 May 2016 05:30 |
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