Neoarchean suprasubduction zone arc magmatism in southern India: Geochemistry, zircon U-Pb geochronology and Hf isotopes of the Sittampundi Anorthosite Complex

Mohan, M. Ram; Satyanarayanan, M.; Santosh, M.; Sylvester, Paul J.; Tubrett, Michael; Lam, Rebecca

doi:10.1016/j.gr.2012.04.004

Cited by 130 publications

(58 citation statements)

References 56 publications

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“…20 in Jayananda et al 2013 for a cartoon version of the overall DC genetic model). Mohan et al (2013) support this model of Jayananda et al (2013), and stress the importance of a conver-gent margin tectonic setting for the EDC, the importance of sub-duction processes (with more recycled crust within this inferred subduction framework in the western part of the EDC), and supra-subduction arc settings. They also see a systematic decrease in involvement of older crust from west to east, which concurs with the systematic younging of dated rocks in the EDC in the same direction.…”

Section: Towards a Coherent Genetic Model For The Dharwar Cratonsupporting

confidence: 66%

A review of the inferred geodynamic evolution of the Dharwar craton over the ca. 3.5–2.5 Ga period, and possible implications for global tectonics

et al. 2014

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Abstract:The geological history and evolution of the Dharwar craton from ca. 3.5-2.5 Ga is reviewed and briefly compared with a second craton, Kaapvaal, to allow some speculation on the nature of global tectonic regimes in this period. The Dharwar craton is divided into western (WDC) and eastern (EDC) parts (separated possibly by the Closepet Granite Batholith), based on lithologi-cal differences and inferred metamorphic and magmatic genetic events. A tentative evolution of the WDC encompasses an early, ca. 3.5 Ga protocrust possibly forming the basement to the ca. 3.35-3.2 Ga Sargur Group greenstone belts. The latter are interpreted as having formed through accretion of plume-related ocean plateaux. The approximately coeval Peninsular Gneiss Complex (PGC) was possibly sourced from beneath plateau remnants, and resulted in high-grade metamorphism of Sargur Group belts at ca. 3.13-2.96 Ga. At about 2.9-2.6 Ga, the Dharwar Supergroup formed, comprising lower Bababudan (largely braided fluvial and subaerial volcanic deposits) and upper Chitradurga (marine mixed clastic and chemical sedimentary rocks and subaqueous volcanics) groups. This supergroup is preserved in younger greenstone belts with two distinct magmatic events, at 2.7-2.6 and 2.58-2.54 Ga, the latter approximately coincident with ca. 2.6-2.5 Ga granitic magmatism which essentially completed cratonization in the WDC. The EDC comprises 2.7-2.55 Ga tonalite-trondhjemitegranodiorite (TTG) gneisses and migmatites, approximately coeval greenstone belts (dominated by volcanic lithologies), with minor inferred remnants of ca. 3.38-3.0 Ga crust, and voluminous 2.56-2.5 Ga granitoid intrusions (including the Closepet Batholith). An east-to-west accretion of EDC island arcs (or of an assembled arc -granitic terrane) onto the WDC is debated, with a postulate that the Closepet Granite accreted earlier onto the WDC as part of a "central Dharwar" terrane. A final voluminous granitic cratonization event is envisaged to have affected the entire, assembled Dharwar craton at ca. 2.5 Ga. When Dharwar evolution is compared with that of Kaapvaal, while possibly global magmatic events and freeboard-eustatic changes at ca. 2.7-2.5 Ga may be identified on both, the much earlier cratonization (by ca. 3.1 Ga) of Kaapvaal contrasts strongly with the ca. 2.5 Ga stabilization of Dharwar. From comparing only two cratons, it appears that genetic and chronologic relationships between mantle thermal and plate tectonic processes were complex on the Archaean Earth. The sizes of the Kaapvaal and Dharwar cratons might have been too limited yet to support effective thermal blanketing and thus accommodate Wilson Cycle onset. However, tectonically driven accretion and amalgamation appear to have predominated on both evolving cratons.Résumé : L'histoire géologique et l'évolution du craton de Dharwar (ϳ3,5-2,5 Ga) sont examinées et sommairement comparées a` celles d'un second craton, celui de Kaapvaal, afin de permettre une certaine spéculation sur la nature des régimes tectoniques globaux duran...

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Section: Towards a Coherent Genetic Model For The Dharwar Cratonsupporting

confidence: 66%

A review of the inferred geodynamic evolution of the Dharwar craton over the ca. 3.5–2.5 Ga period, and possible implications for global tectonics

et al. 2014

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“…The parental magmas of these rocks show tholeiitic composition and were generated in an oceanic arc environment (Dutta et al, 2011). Although previous Sm-Nd studies on the anorthosites in this complex yielded age from 3000 to 2900 Ma (Bhaskar Rao et al, 1996), in a recent study, Mohan et al (2013) reported zircon U-Pb age of 2541 ± 13 Ma. (iii) The Chalk hills of Salem Mafic-Ultramafic Complex (SMUC) with large magnesite deposits (Murthy, 1979;Kutty et al, 1986;Reddy et al, 1995) exposed north of Salem town, in the north-central part of the CSZ.…”

Section: Introductionmentioning

confidence: 91%

The mafic–ultramafic complex of Aniyapuram, Cauvery Suture Zone, southern India: Petrological and geochemical constraints for Neoarchean suprasubduction zone tectonics

Yellappa

Venkatasivappa

Koizumi

et al. 2014

Journal of Asian Earth Sciences

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“…A cyclic opening and closing within the Madurai Block therefore could not be ruled out. In this regard, the two periods with significant magmatic and metamorphic activity are also marked by largely mantle-derived anorthositegabbro suite of rocks, Sittampundi (at northern extreme of the Madurai Block generally included within CSZ domain) in the Neoarchaean (Bhaskar Rao et al 1996;Ram Mohan et al 2013) and Kadavur (Kooijman et al 2011;Teale et al 2011) in mid-Neoproterozoic. These episodes of maficultramafic magmatism could be taken as evidences to support the hypothesis that the mantle-derived magma was the much sought after heat-source for the magmatism and metamorphism.…”

Section: Previous Geochronological Studies and Link Between Magmatismmentioning

confidence: 99%

Rb–Sr and Sm–Nd study of granite–charnockite association in the Pudukkottai region and the link between metamorphism and magmatism in the Madurai Block

2016

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Pudukkottai region in the northeastern part of the Madurai Block exposes the garnetiferous pink granite that intruded the biotite gneiss. Charnockite patches are associated with both the rock types. Rb-Sr biotite and Sm-Nd whole-rock isochron ages indicate a regional uplift and cooling at ∼550 Ma. The initial Nd isotope ratios (ε t Nd = −20 to −22) and Nd depleted-mantle model ages (T DM = 2.25 to 2.79 Ga) indicate a common crustal source for the pink-granite and associated charnockite, while the biotite gneiss and the charnockite within it represent an older crustal source (ε t Nd = −29 and T DM = >3.2 Ga). The Rb-Sr whole-rock data and initial Sr-Nd isotope ratios also help demonstrate the partial but systematic equilibration of Sr isotope and Rb/Sr ratios during metamorphic mineral-reactions resulting in an 'apparent whole-rock isochron'. The available geochronological results from the Madurai Block indicate four major periods of magmatism and metamorphism: Neoarchaean-Paleoproterozoic, Mesoproterozoic, mid-Neoproterozoic and late-Neoproterozoic. We suggest that the high-grade and ultrahigh-temperature metamorphism was preceded by magmatism which 'prepared' the residual crust to sustain the high P -T conditions. There also appears to be cyclicity in the tectono-magmatic events and an evolutionary model for the Madurai Block should account for the cyclicity in the preserved records.

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Neoarchean suprasubduction zone arc magmatism in southern India: Geochemistry, zircon U-Pb geochronology and Hf isotopes of the Sittampundi Anorthosite Complex

Cited by 130 publications

References 56 publications

A review of the inferred geodynamic evolution of the Dharwar craton over the ca. 3.5–2.5 Ga period, and possible implications for global tectonics

A review of the inferred geodynamic evolution of the Dharwar craton over the ca. 3.5–2.5 Ga period, and possible implications for global tectonics

The mafic–ultramafic complex of Aniyapuram, Cauvery Suture Zone, southern India: Petrological and geochemical constraints for Neoarchean suprasubduction zone tectonics

Rb–Sr and Sm–Nd study of granite–charnockite association in the Pudukkottai region and the link between metamorphism and magmatism in the Madurai Block

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