Publication Date:
2023-09-12
Description:
The Bundelkhand Craton has a well-developed E-W trending Mouranipur-Babina Greenstone Belt (MBGB), which has excellent preservation of BIFs, cherts, sandstones, greywackes, quartzites, and associated komatiite-basalt-andesites. The pillow, massive basalts, komatiite basalts, andesites of Baragaon, BIFs of Saprar and Babina, chocolate-colored cherts from Babina, sandstones of Bhauti, fuchsite quartzites and metagreywackes from Swargeswarashram are studied for petrology and geochemistry to decipher the tectonic evolution of the Bundelkhand Craton. The CaO/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, (Gd/Yb)〈sub〉N〈/sub〉〉1, positive Nb anomalies, La/Sm, La/Ta, Nb/Th, and high MgO contents (〉20 wt.%) of the komatiite basalts reflect a mantle plume source for the early stage greenstone growth. Bimodal metavolcanics with tholeiitic to calc-alkaline affinity shows basalt-andesite-dacite-rhyolite differentiation trend in a convergent setting (arc-back arc), where partial melts are generated from thick metamorphosed basaltic crust after mantle plume. The metagreywackes, sandstones, and cherts are derived from felsic to mafic sources as indicated by their Cr〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, TiO〈sub〉2〈/sub〉-Al〈sub〉2〈/sub〉O〈sub〉3,〈/sub〉 and Zr, Th/Yb-Ta/Yb relationship. The BIFs of Saprar are characterized by low silica and high iron, whereas for Babina, the opposite is true. The Cu, Zn, Pb, V, Sr, and Ba contents of Babina BIF are very high compared to BIFs of Saprar, which in turn record high Sc, Cr, and Zr contents. ∑REE-Cu+Co+Ni, SiO〈sub〉2〈/sub〉-K〈sub〉2〈/sub〉O/Na〈sub〉2〈/sub〉O, and Cr-Ni discriminations infer that BIFs of MBGB are of Algoma type. Thus, the geochemical signatures of the volcano-sedimentary sequences strongly endorse Neoarchean plume-arc accretion tectonics in this greenstone belt, like other north-south trending greenstone belts of India.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
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