Geochemistry and Sm-Nd isotope systematics of mafic-ultramafic rocks from the Babina and Mauranipur greenstone belts, Bundelkhand Craton, India: Implications for tectonic setting and Paleoarchean mantle evolution

Autor(es)

Singh, Pradip K. ^[1] ; Verma, Sanjeet K. ^[2] ; Moreno, Juan A. ^[3] ; Singh, Vinod K. ^[4] ; Malviya, Vivek P. ^{[5, 6]} ; Oliveira, Elson P. ^[7] ; Mishra, Sumit ^{[4, 8]} ; Arima, Makoto ^[5]

Afiliação do(s) autor(es)

^[1] IPICYT, Posgrad Div Geociencias Aplicadas, Camino Presa San Jose 2055, San Luis Potosi 78216 - Mexico

^[2] IPICYT, Div Geociencias Aplicadas, Camino Presa San Jose 2055, San Luis Potosi 78216 - Mexico

^[3] Univ Nacl Cordoba, CONICET, Fac Ciencias Exactas Fis & Nat, Ctr Invest Ciencias Tierra CICTERRA, Av Velez Sarsfield 1611, Edificio CICTERRA, Cordoba - Argentina

^[4] Bundelkhand Univ, Inst Earth Sci, Dept Geol, Jhansi, Uttar Pradesh - India

^[5] Yokohama Natl Univ, Grad Sch Environm & Informat Sci, Hodogaya Ku, 79-7 Tokiwadai, Yokohama, Kanagawa 2408501 - Japan

^[6] 24E Mayur Residency Ext, Lucknow 226015, Uttar Pradesh - India

^[7] Univ Campinas UNICAMP, Inst Geosci, Dept Geol & Nat Resources, POB 6152, BR-13083970 Campinas, SP - Brazil

^[8] HNB Garhwal Univ, Sch Earth Sci, Dept Geol, Srinagar 246174, Pauri Garhwal - India

• Tipo de documento: Artigo Científico
• Fonte: LITHOS; v. 330, p. 90-107, APR 2019.
• Citações Web of Science: 0

Resumo

The Paleoarchean geodynamical evolution of the Bundelkhand Craton is discussed based on the geochemistry (major, trace and rare earth elements) and Sm-Nd isotope systematic of mafic-ultramafic rocks from volcanosedimentary succession of the Babina and Mauranipur greenstone belts. The petrography and mineral assemblages of these mafic-ultramafic rocks imply that they were gone through greenschist to amphibolite facies metamorphism. Geochemical analyses indicate that mafic rocks from the Babina are characterized by SiO2 = 43.9-512 wt%, MgO = 5.4-11.0 wt%, TiO2 = 03-1.14 wt% and Mg\# = 44-77, whereas the Mauranipur are characterized by higher silica (51.8-55.6 wt%), MgO = 6.9-9.5 wt% and Mg\# = 59-70. The ultramafic rocks from the Babina and Mauranipur contain SiO2 = 46.9-50.3 wt%, MgO = 20.2-21.1 wt%, TiO2 = 0.33-0.46 wt% and Mg\# = 77-82. Six samples of mafic-ultramafic rocks from the Babina greenstone belt yield Sm-147-Nd-143 whole rock isochron age of ca. 3.4 Ga. Sm-Nd isotopic studies of mafic rocks from the Babina and Mauranipur reveal that they were derived from a depleted mantle source. Bivariate diagrams such as Cr vs. Ni and V suggest that these magmas might have evolved through fractionation of clinopyroxene and olivine. The mafic rocks from the Babina displayed almost a flat REE and HFSE profile {[}(La/Yb)(PM)= 0.87-1.40] with negative Nb (Nb/Nb{*} = 0.13-0.77) and positive Pb anomalies that could be attributed to metasomatic agents derived from subducting crustal rocks. The Mauranipur mafic rocks show slightly enriched REE {[}(La/Yb)(PM) = 1.1-1.7; (La/Sm)(PM) = 1.1-2.0] with negative Nb anomalies (Nb/Nb{*} = 0.13-0.77), which are most likely the effects of crustal contamination. The ultramafic rocks from both areas and ultramafic cumulate rock from the Mauranipur display a progressive enrichment from Th, La to Yb, with negative Nb anomalies (Nb/Nb{*}= 0.40-0.73) with lack of Zr anomalies (Zr/Zr{*} = 0.10-0.30) that could be attributed to their derivation from shallower mantle. These data collectively suggest that the mafic-ultramafic rocks have been interpreted to be derived from oceanic crust in a subduction-related setting with depleted mantle composition. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 12/15824-6 - Evolução de terrenos arqueanos do Cráton São Francisco e Província Borborema: implicações para processos geodinâmicos e paleoambientais globais
• Beneficiário: Elson Paiva de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Temático