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Geochemistry and geotectonic implication of basic volcanic rocks in the Lower Gondwana sequence (Upper Palaeozoic) of the Sikkim Himalayas

Published online by Cambridge University Press:  01 May 2009

S. Sinha Roy  and
H. Furnes
S. Sinha Roy
Affiliation:
Geological Survey of India, 27, Chowringhee Road, Calcutta 70016, India
H. Furnes
Affiliation:
Geologisk Institutt, Universitetet i Bergen, Avd. A., J. Frielesgt 1, 5014 Bergen, Norway
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Summary

As in Kashmir and Arunachal Pradesh (NEFA) Himalayas, the Upper Palaeozoic (Lower Gondwana) sequence in Sikkim Himalayas contains basic lavas. These are interbedded with boulder bed/pebble slate, sandstone andshale, exposed in a tectonic window. Geochemically the basic lavas are characterized by high contents of TiO2, K2O, P2O5 and ‘incompatible’ trace elements. The chemistryis compatible with a small degree of partial melting under high pressure ofa titan-phlogopite-bearing peridotite mantle. The only primary quench phases are frequent apatite, magnetite and profuse ilmenite, the latter accounting for the high FeO/Fe2O3 ratio of the rock, and demonstrating rapid crystallization. The geochemistry of the lavas appears to be consistent with basic volcanism associated with the initiation of continental rifting. From this study and from a consideration of the geochemistry of the volcanic rocks of similar age in Kashmir area, it is suggested that rifting of the northern continental margin of the Indian plate and formation of a transitional crust during Upper Palaeozoic times are important geotectonic features in the Himalayan region.

Type
Articles
Information
Geological Magazine , Volume 115 , Issue 6 , November 1978 , pp. 427 - 436
Copyright
Copyright © Cambridge University Press 1978

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References

Auden, J. B. 1935. Traverses in the Himalayas. Rec. geol. Surv. India 69, 123–69.Google Scholar
Burke, K. & Dewey, J. F. 1973. Plume generated triple junctions: key indicators in applying plate tectonics to old rocks. J. geol. 81, 406–33.CrossRefGoogle Scholar
Burke, K. & Whiteman, A. J. 1973. Uplift, rifting and the break-up of Africa. In Implication of Continental Drift to Earth Sciences, vol. 2 (ed. Tarling, D. H. & Runcorn, C. K.), pp. 735–55. London: Academic Press.Google Scholar
Cann, J. R. 1970. Rb, Sr, Y, Zr and Nb in some ocean floor basalt rocks. Earth Planet. Sci. Lett. 10, 7–11.CrossRefGoogle Scholar
Chazen, S. J. & Vogel, T. A. 1974. Distribution of Ti and P in oceanic basalts as a test of origin. Contr. Miner. Petrol. 43, 307–16.CrossRefGoogle Scholar
Crawford, A. R. 1974. The Indus suture line, the Himalayas, Tibet and Gondwanaland. Geol. Mag. 111, 369–83.CrossRefGoogle Scholar
Floyd, P. A. & Winchester, J. A. 1975. Magma type and tectonic setting discrimination trace element analysis. Earth Planet. Sci. Lett. 19, 290–300.Google Scholar
Forbes, W. C. & Flower, M. F. J. 1974. Phase relations of titan-phlogopite K2Mg4TiAl2Si6O20(OH)4: a refractory phase in the upper mantle. Earth Planet. Sci. Lett. 22, 60–6.CrossRefGoogle Scholar
Frakes, L. E., Kemp, E. M. & Crowell, J. C. 1975. Late Paleozoic glaciation: Part VI Asia. Bull. geol. Soc. Am. 86, 454–64.2.0.CO;2>CrossRefGoogle Scholar
Frey, F., Haskin, M. A., Poetz, J. A. & Haskin, L. A. 1968. Rare earth abundances in some basaltic rocks. J. geophys. Res. 73, 6085–98:CrossRefGoogle Scholar
Gansser, A. 1964. Geology of the Himalayas. New York: Interscience.Google Scholar
Gass, I. G. 1970. Tectonic and magmatic evolution of the Afro-Arabian dome. In African Magmatism and Tectonics (ed. Clifford, T. N. and Gass, I. G.), pp. 285–300. Edinburgh: Oliver & Boyd.Google Scholar
Gast, P. W. 1968. Trace element fractionation and the origin of tholeiitic and alkaline magma types. Geochim. cosmochim. Acta. 32, 1057–86.CrossRefGoogle Scholar
Ghosh, A. M. N. 1956. Recent advances in geology and structure of Eastern Himalayas. Proc. 43rd. Indian Sci. Congr. 2, 85–99.Google Scholar
Herrmann, A. G., Potts, M. J. & Knabe, D. 1974. Geochemistry of rare earth elements in spilites from the oceanic and continental crust. Contr. Miner. Petrol. 44, 1–16.CrossRefGoogle Scholar
Kay, R. & Gast, P. W. 1973. The rare earth content and origin of alkali-rich basalts. J. geol. 81, 653–82.CrossRefGoogle Scholar
Kay, R., Hubbard, N. J. & Gast, P. W. 1970. Chemical characteristics and origin of oceanic ridge volcanic rocks. J. geophys. Res. 75, 1585–613.CrossRefGoogle Scholar
Nakazawa, K. & Kapoor, H. M. 1973. Spilitic pillow lava in Panjal Trap of Kashmir, India. Mem. Faculty Sci. Kyoto Univ. Ser. geol. Mineral. 39, 83–98.Google Scholar
Nautiyal, S. P., Jangpangi, B. S., Singh, P., Guha Sarkar, T. K., Bhate, V. D., Raghavan, M. R. & Sahai, T. N. 1964. Preliminary note on the geology of Bhutan Himalayas. Proc. 22nd Int. geol. Congr. New Delhi, 11, 1–12.Google Scholar
Pascoe, E. H. 1973. A Manual of the Geology of India and Burma, 3rd ed.Google Scholar
Pearce, J. A. & Cann, J. R. 1971. Ophiolite origin investigated by discriminant analysis using Ti, Zr and Y. Earth Planet. Sci. Lett. 12, 338–49.CrossRefGoogle Scholar
Pearce, J. A. & Cann, J. R. 1973. Tectonic setting of basic volcanic rocks determined using trace element analysis. Earth. Planet. Sci. Lett. 19, 290–300.CrossRefGoogle Scholar
Philpotts, J. A., Schnetzler, C. C. & Hart, S. R. 1969. Submarine basalts: some K, Rb, Sr, Ba, rare earth, H2O and CO2 data bearing on their alteration, modification by plagioclase and possible source materials. Earth Planet. Sci. Lett. 7, 293–9.CrossRefGoogle Scholar
Rupke, J. 1968. Note on the Blaini boulder bed of Tehri Garhwal, Kumaon Himalayas. J. geol. Soc. India 9, 171–7.Google Scholar
Sahni, M. R. & Srivastava, J. P. 1956. Discovery of Eurydesma and Conularia in Eastern Himalayas and description of associated faunas. J. pal. Soc. India 1, 202–14.Google Scholar
Schnetzler, C. C. & Philpotts, J. A. 1970. Partition coefficients of rare earth elements between igneous matrix material and rock forming mineral phenocrysts II. Geochim. cosmochim. Acta, 34, 331–40.CrossRefGoogle Scholar
Shimizu, N. & Arculus, R. J. 1975. Rare earth element concentrations ina suite of basanoids and alkali olivine basalts from Grenada, Lesser Antilles. Contr. Miner. Petrol. 50, 231–40.CrossRefGoogle Scholar
Sinha Roy, S. 1973 a. Tectonic belts in Sikkim-Darjeeling Himalayas and their geodynamic significance. In Geodynamics of the Himalayan Region (ed. Gupta, H. K.), pp. 156–66. Hyderabad: Nat. Geophysics Res. Inst.Google Scholar
Sinha Roy, S. 1973 b. Gondwana pebble slate in the Rangit valley tectonic window, Darjeeling Himalayas and its significance. J. geol. Soc. India 14, 31–9.Google Scholar
Sinha Roy, S. 1975. Polymetamorphism in the Daling rocks from a part of theEastern Himalayas and some problems of Himalayan metamorphism. Himalayan geol. 4, 74–101.Google Scholar
Sinha Roy, S. 1976 a. On the origin of ophiolite complexes in the Southern Tethys region: Discussion. Tectonophysics, 34, 257–61.CrossRefGoogle Scholar
Sinha Roy, S. 1976 b. A possible Himalayan microcontinent. Nature, Lond. 263, 117–20.CrossRefGoogle Scholar
Sinha Roy, S. 1977 a. Tectonic elements in the Eastern Himalayas and geodynamic model of evolution of the Himalayas. In Tectonics and Metallogeny ofSouth and East Asia (ed. Ray, S.). Miscellaneous Publication. Geol. Surv. India 34, 57–74.Google Scholar
Sinha Roy, S. 1977 b. Gondwana and related rocks in the Himalayas and adjacent areas and their bearing on Palaeozoic-Mesozoic plate tectonics in the eastern Tethys region. Proc. 4th Int. Gondwana Symp. Calcutta (in the press).Google Scholar
Smith, R. E. & Smith, S. E. 1976. Comments on the use of Ti, Zr, Y, Sr, K, P and Nb in classification of basaltic magmas. Earth Planet. Sci. Lett. 32, 114–20.CrossRefGoogle Scholar