Abstract
Deccan volcanism with a tremendous burst of volcanic activity marks a unique episode in Indian geological history and covers nearly two third of Peninsular India. Occurrences of mafic sill in the continental basalts are rather rare throughout the flood basalt provinces and only few sporadic reports have been described from different Continental Flood Basalts of the world. In the present article, petrology of mafic sill from the Narshingpur-Lakhnadon section of Eastern Deccan province of India has been presented. The mafic sill in the field is found to occur in a relatively deep valley amidst Gondwana rocks, which occur as the basement of the extrusion. The sill is spatially associated with three initial flows viz. flow I, II and III of adjacent Narshingpur-Harrai-Amarwara section. The sill in its central part is a medium grained rock and petrographically corresponds to dolerite containing augite, plagioclase and rare olivine grains; the chilled facies of the sill is characterized by phenocrysts of olivine, plagioclase and augite that are set in groundmass consisting predominantly of plagioclase, olivine and glass. Mineral chemistry indicates that olivine phenocrystal phase is magnesian (Fo61). Plagioclase phenocrystal composition ranges from An 51 to An 71 whereas the same variation of the groundmass plagioclase composition corresponds to An 31 to An 62. The overlap in the compositions for groundmass and phenocrystal plagioclase may be explained due to fluctuating PH2O condition. The pyroxene compositions (both groundmass and phenocryst) in majority of the cases are clubbed well within the augite field, however, in a few cases, groundmass compositions are found to fall in the sub-calcic augite and pigeonite field. Some zoned pyroxene phenocrysts, characteristically display different types of zoning patterns. Opaque minerals in the mafic sill are found to be magnetite and ilmenite and this coexisting iron-oxide composition helps to constrain the prevalent fO2 condition in the parent magma. The geochemistry of the mafic sill and associated basaltic lava flows indicates close genetic link amongst them. Critical consideration of trace elements indicates a distinct enriched mantle source (EM-I/EM-II/HIMU) for the parental magma. Trace element modeling indicates that equilibrium batch-melting of plume source followed by fractionation of olivine, clinopyroxene and plagioclase and subsequent heterogeneous mixing of melt and settled crystals can very well explain the genesis of the mafic sill and the associated basaltic flows.
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References
Alexander, P.O. and Paul, D.K. (1977) Geochemistry and Sr isotopic composition of basalts from Eastern Deccan basaltic province, India. Min. Mag., v.41, pp.165–172.
Bakshi, A.K. (1994) Geological studies on whole rock basalts, Deccan traps, India: evalution of the timing of volcanism relative to the K-T boundary. Earth Planet. Sci. Lett., v.121, pp.43–56.
Beane, J.E., Turner, C.A., Hooper, P.R., Subbarao, K.V. and Walsh, J.N. (1986) Stratigraphy, composition and form of the Deccan Basalts, Western Ghats, India. Bull. Volcanol., v.48, pp.61–83.
Buddington, A.F. and Lindsley, D.H. (1964) Iron Titanium oxide minerals and their synthetic equivalents. Jour. Petrol., v.5, pp.310–357.
Cartwright, J. and Hansen, D.M. (2006) Magma transport through the crust via interconnected Sill Complexes. Geology, v.34, pp.929–932.
Chayes, F. (1949) A simple point counter for thin section. Amer. Min., v.36, pp.1–11.
Courtillot, V., Feraud, Maluski, D., Moreau, M.G. and Besse, J. (1988) Deccan Flood basalts and the Cretaceous/Tertiary boundary. Nature, v.333, pp.843–846.
Crookshank, H. (1936) Geology of the northern slopes of the Satpura between the Morand and Sher rivers. Mem. Geol. Surv. India, v.66(2), 56p.
De, A. (1972) Structural feature of the Deccan Trap tholeiitic basalts flows of southern Kutch. Proc. Indian Sci. Congress 56th Session, Part III, pp.180.
De, A. (1974) Short and Long distance correlation of Deccan Trap Lava Flows. Bull. Geol. Min. Met. Soc. India (Abst), v.47, pp.50.
De, A. (1996) Entablature structure in Deccan Trap flows: its nature and probable mode of origin. Gondwana Geol. Mag., v.2, pp.439–447.
Deshmukh, S.S, Sano, T. and Nair, K.K.K. (1996) Geology and chemical stratigraphy of the Deccan basalts of Chikaldara and Behramghat sections of the eastern part of the Deccan Trap province, India. Gondwana Geol. Mag., v.2, pp.1–22.
Duncan, R.A. and Pyle, D.G. (1988) Rapid eruption of the Deccan flood basalts at the Cretaceous/Tertiary boundary. Nature, v.333, pp.841–843.
Fermor, L.L. (1934) On the chemical composition of the Deccan Trap flows of Linga, Chhindwara district, Central province. Rec. Geol. Surv. India, v.64, 344p.
Green, J. and Poldervaart, A. (1958) Petrochemical fields and trends. Geochim Cosmochim. Acta., v.13, pp.87–122.
Henderson, P. (1984) General geochemical properties and abundance of the rare earth elements. In: P. Henderson (Ed.), Rare Earth Element Geochemistry, Elsevier, Amsterdam, pp.1–32.
Irvine, T.N. and Baragar, W.R.A. (1971) A guide to the chemical classification of common volcanic rocks. Canadian Jour. Earth. Sci., v.8, pp.523–528.
Ishii, T. (1975) The relations between temperature and composition of pigeonite in some lavas and their application to geothermometry. Mineral Jour., v.8, pp.48–57.
Jensen, L.S. (1976) A new cationic plots for classifying subalkalic volcanic rocks. Ontario Division of Mines. MP66, pp.22.
Krishnamurthy, P. and Cox, K.G. (1977) Picrite basalts and related lavas from the Deccan Traps and Western India. Contrib. Mineral. Petrol., v.62, pp.53–75.
Kuno, H. (1968) Differentiation of Basalt magmas In: H.H. Hess and A. Poldervaart (Eds.), Basalts, v.2, pp.623–688.
Kushiro, I. (1972) Effects of water on the composition of magmas formed at high pressures. Jour. Petrol., v.13, pp.311–334.
Lindsley, D.H. (1983) Pyroxene thermometry. Amer. Mineral., v. 68, pp.477–493.
Mahoney, J.J, Sheth, H.C. and Chandrasekharam, D. (2000) Geochemistry of flood basalts of the Toranmal section, Northern Deccan Traps, India: implications for regional Deccan stratigraphy. Jour. Petrol., v.41,pp.1099–1120.
Mcdonald, G.A. (1967) Forms and structures of Extrusive basaltic rocks. In: H.H. Hess and A. Poldervaart (Eds.), Basalts:The Poldervaat Treatise on rocks of Basaltic composition. New York, Interscience Publ., pp.1–62.
Momme, P. and Wilson, J.R. (2002) The Kraemer Island macrodyke, East Greenland: solidification of a flood basalt conduit. Geol. Mag., v.139, pp.171–190.
Morgan, W.J. (1972) Plate motions and deep mantle convection. Mem. Geol. Soc. Amer., v.132, pp.7–22.
Morimoto, N. (1989) Nomenclature of pyroxenes. Canad. Min., v.27, pp. 143–156.
Morse, S.A. (1980) Basalts and phase diagrams. Springer, New York, 493p.
Muir, I. and Tilley, C.E. (1964) Iron enrichment and pyroxene fractionation in tholeiites. Geol. Jour., v.4, pp.143–156.
Nair, K.K.K., Chatterjee, A.K. and Sano, T. (1996) Stratigraphy and geochemistry of the Deccan basalts along Toranmal section, western Satpura region. Gondwana Geol. Mag., v.2, pp.23–48.
Papike, J.J., Cameron, K.L. and Baldwin, K. (1974) Amphiboles and Pyroxenes: characterization of other than quadrilateral components and estimates of ferric iron from microprobe data. EOS Trans., Amer.Geophysics. Union, v.60, pp.420–421.
Pattanayak, S.K. and Shrivastava, J.P. (1999) Petrography and major-oxide geochemistry of Basalts from Eastern Deccan volcanic province. Mem. Geol. Soc. India no.43, pp.233–270.
Paul, D.K., Ray, A., Das, B., Patil, S.K. and Biswas, S.K. (2008) Petrology, geochemistry and paleomagnetism of the earliest magmatic rocks of Deccan volcanic Province, Kutch, Northwest India. Lithos, v.102, pp.237–259.
Peng, Z.X. and Mahoney, J.J. (1995) Drill hole lavas from the northwestern Deccan Traps and the evolution of Reunion hot spot mantle. Earth and Planet Sci Lett., v.134, pp.169–185.
Peng, Z.X, Mahoney, J.J., Hooper, P.R., Macdougall, J.D. and Krishnamurthy, P. (1998) Basalts of the north eastern Deccan Traps, India: isotopic and elemental geochemistry and relation to southwestern Deccan stratigraphy. Jour. Geophys. Res., v.103(B-12), pp.29843–29865.
Poldervaat, A. and Hess, H.H. (1951) Pyroxene in the crystallization of basaltic magma. Jour. Geol., v.59, pp.472–489.
Ray, A., Patil, S.K., Paul, D.K., Biswas, S.K., Das, B. and Pant, N.C. (2006) Petrology, geochemistry and magnetic properties of Sadara Sill: evidence of rift related magmatism from Kutch basin, northwest India. Jour. Asian Earth Sci., v.27, pp.907–921.
Roedder, P.L. and Emslie, R.F. (1970) Olivine-liquid equilibrium. Contrib. Mineral. Petrol., v.29, pp.275–289.
Self, S., Jay, A.E., Widowson, M. and Keszthelyi, L.P. (2008) Correlation of the Deccan and Rajahmundry Trap Lavas: Are these the longest and largest lava flows on the earth? Jour. Volcanol. Geoth. Res., v.172, pp.3–19.
Sen, G. (1980) Mineralogical variations in the Delakhari Sill, Deccan Trap Intrusion, Central India. Contrib. Mineral. Petrol., v.75, pp.71–78.
Sen, G. and Cohen, T.H. (1994) Deccan intrusion, crustal extension, doming and the size of the Deccan-Reunion plume head; In: K.V. Subbarao (Ed.), Volcanism. Mem. Geol. Soc. India, no.10, pp.69–90.
Sengupta, P. (2005) Structure, Petrology and Geochemistry of the Deccan Traps, south of Narsingpur, Madhya Pradesh. Unpubl. Ph.D. thesis, Univ. Calcutta, 188p.
Sheth, H.C., Duncan, R.A., Chandrasekharam, D. and Mahoney, J.J. (1997) Early alkaline magmatism in the Deccan Traps: implications for plume incubation and lithospheric rifting. Phys. Earth Planet. Inter., v.104, pp.371–376.
Storey, M., Mahoney, J.J. and Saunders, A.D. (1997) Cretaceous Basalts in Madagascar and the transition between plume and continental lithosphere Mantle sources. Geophys. Monograph.. v.100, pp.95–122.
Stormer, J.C. (1983) The effects of recalculation on estimates of temperature and oxygen fugacity from analyses of multicomponent iron-titanium oxides. Amer. Mineral., v.68, pp.586–594.
Streckeisen, A. (1976) To each plutonic rock its proper name. Earth Sci. Rev., v.12, pp.1–33.
Sun, S.S. and Mcdonough, W.F. (1989) Chemical and isotopic systematics of ocean basalts, implications for mantle composition and processes. Geol. Soc. London Spec. Publ., v.42, pp.313–345.
Svensen, H., Planke, S. and Corfu, F. (2010) Zircon dating ties NEAtlantic sill emplacement to initial Eocene global warming. Jour. Geol. Soc. London, v.167, pp.433–436.
Swanson (1967) Stratigraphic and lithologic variations in the Columbia River Basalt. Amer. Jour. Sci., v.259, pp.583–611.
Thornton, C.P. and Tuttle, O.F. (1960) Chemistry of Igneous Rocks. I. Differentiation index. Amer. Jour. Sci., v.258, pp.664–684.
Venkatesan, T.R., Pande, K. and Gopalan, G. (1993) Did ocean volcanism predate the Cretaceous/Tertiary transition? Earth Planet. Sci. Lett., v.119, pp.181–189.
Vouri, S.K. and Luttinen, A.V. (2003) The Jurassic Gabbroic intrusions of Utpostane and Muren: insight into Karoo-related plutonism in Dronning Maud Land, Antarctica. Antartic Science, v.15, pp.283–301.
Waters, A.C. (1961) Stratigraphic and lithologic variations in the Columbia River Basalts. Amer. Jour. Sci., v.259, pp.583–611.
Watson, S. and Mckenzie, D. (1991) Melt generation by plumes: a study of Hawaiian volcanism. Jour. Petrol., v.32, pp.501–537.
Weaver, B.L. (1991) The origin of ocean island basalt end-member compositions: trace elements and isotopic constraints. Earth Planet. Sci. Lett., v.104, pp.381–397.
West, W.D. (1958) The petrography and petrogenesis of fortyeight flows of Deccan Traps penetrated by borings in western India. Trans. Indian Nat. Inst. Sci., v.4, pp.1–56.
Yedekar, D.B., Aramaki, S., Fujii, T. and Sano, T. (1996) Geochemical signature and stratigraphy of the Chhindwara-Mandla sector of the Eastern Deccan volcanic province and problems of its correlation. Gondwana Geol. Mag., v.2, pp.49–68.
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Sengupta, P., Ray, J. Petrology of the mafic sill of Narshingpur-Lakhnadon section, Eastern Deccan volcanic province. J Geol Soc India 77, 309–327 (2011). https://doi.org/10.1007/s12594-011-0037-0
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DOI: https://doi.org/10.1007/s12594-011-0037-0