Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-18T18:50:30.931Z Has data issue: false hasContentIssue false
  • English
  • Français

Petrology of Mg-Mn amphibole-bearing assemblages in manganese silicate rocks of the Sausar Group, India

Published online by Cambridge University Press:  05 July 2018

Somnath Dasgupta ,
P. K. Bhattacharya ,
G. Chattopadhyay ,
H. Banerjee ,
N. Majumdar ,
M. Fukuoka  and
Supriya Roy
Somnath Dasgupta
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta-700 032, India
P. K. Bhattacharya
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta-700 032, India
G. Chattopadhyay
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta-700 032, India
H. Banerjee
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta-700 032, India
N. Majumdar
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta-700 032, India
M. Fukuoka
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta-700 032, India
Supriya Roy
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta-700 032, India
Get access Rights & Permissions [Opens in a new window]

Abstract

Mg-Mn amphibole (tirodite), with or without pyroxmangite in the total absence of pyroxenes and high-calcic pyroxenoids, occurs in the Mn silicate rocks of the Sausar Group, India. The rocks were metamorphosed to amphibolite facies condition (T ∼ 650°C, P ∼ 6 kbar). Tirodite-pyroxmangite pairs developed in both carbonate-free and rhodochrosite-bearing assemblages. Also tirodite coexists with either kutnahorite or manganoan calcite in the absence of pyroxmangite. Mineral reactions inferred from modal abundances and compositions of the phases indicate stabilization of the amphibole alone from a bivalent cation-bearing residual unbuffered XCO2 system with XMn < 0.3. On the other hand, tirodite-pyroxmangite pairs appeared in unbuffered low to intermediate XCO2 assemblages with XMn > 0.35. Pyroxenes and high-calcic pyroxenoids did not appear in the present situation, though they occur elsewhere in rocks with broadly similar contents of immobile components. Closely associated assemblages of diverse mineralogy suggest that the XMn and XCO2, rather than the physical conditions of metamorphism, are the decisive factors in promoting the observed phase assemblages.

Keywords

magnesiummanganeseamphiboletiroditeSausar GroupIndia
Type
Mineralogy
Information
Mineralogical Magazine , Volume 52 , Issue 364 , March 1988 , pp. 105 - 111
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

*

Dept. of Geology, Kyushu University, Fukuoka, Japan.

References

Abrecht, J., and Peters, T.J. (1980) Contrib. Mineral. Petrol. 74, 261–9.CrossRefGoogle Scholar
Bhattacharya, P.K., Dasgupta, S., Fukuoka, M., and Roy, S. (1984) Ibid. 87, 65–71.Google Scholar
Bilgrami, S.A. (1955) Mineral. Mag. 30, 633–47.Google Scholar
Brown, P.E., Essene, E.J., and Peacor, D.R. (1980) Contrib. Mineral. Petrol. 74, 417-25.CrossRefGoogle Scholar
Calvert, S.E., and Price, N.B. (1970) Ibid. 29, 215–33.Google Scholar
Dasgupta, S., Banerjee, H., and Majumdar, N. (1984) Neus Jahrb. Mineral. Abh. 150, 95–102.Google Scholar
Dunn, J.A., and Roy, P.C. (1938) Rec. G.S.I. 73, 295–8.Google Scholar
Ghose, S., Forbes, W.C., and Phakey, P.P. (1974) Ind. J. Earth Sci. 1, 3742.Google Scholar
Huebner, J.S. (1967) Stability relations of minerals in the system Mn-Si-C-O. Ph.D. Thesis. The Johns Hopkins University, Baltimore.Google Scholar
Huebner, J.S. (1986) Am. Mineral. 71, 111–22.Google Scholar
Jaffe, H.W., Groenveld, M.W., and Selchow, D.H. (1961) Ibid. 46, 642–53.Google Scholar
Klein, C. (1966) J. Petrol. 7, 246–305.CrossRefGoogle Scholar
Kobayashi, H. (1977) J. Geol. Soc. Japan 83, 537- 42.CrossRefGoogle Scholar
Leake, B.E. (1978) Am. Mineral. 63, 1023–52.Google Scholar
Maresch, W.V., and Czank, M. (1983) Ibid. 68, 744–53.Google Scholar
Peters, Tj. (1971) Contrib. Mineral. Petrol. 32, 267- 73.CrossRefGoogle Scholar
Peters, Tj. Valarelli, J.V., Coutinho, J.M. V., Sommerauer, J., and Van Raumer, J. (1977) Schweiz. Mineral. Petrog. Mitt. 57, 313-27.Google Scholar
Peters, Tj. Trommsdorff, V., and Sommerauer, J. (1980) In Geology and Geochemistry of Manganese. Vol. I (Varentsov, I.M., and Grasseley, G., eds.) 271–83.Google Scholar
Petersen, E.U., Amovitz, L.M., and Essene, E.J. (1984) Am. Mineral. 69, 472-80.Google Scholar
Roy, S. (1966) Syngenetic manganese formations of lndia. J.U. Press.Google Scholar
Roy, S. (1974) Acta Mineral. Petrog. 21, 269–73.Google Scholar
Roy, S. Dasgupta, S., Majumdar, N., Banerjee, H., Bhattacharya, P.K., and Fukuoka, M. (1986) Neus Jahrb. Mineral. Mh. 251-9.Google Scholar
Tavera, I.A., and Alexandri, R. (1972) Acta Mineral. Petrog. 20, 387–8.Google Scholar
Varentsov, I.M. (1964) Sedimentary manganese ores. Elsevier.Google Scholar
Winter, G.A., Essene, E.J., and Peacor, D.R. (1981) Am. Mineral. 66, 278–89.Google Scholar