First report of eudialyte occurrence from the Sushina hill region, Purulia district, West Bengal

Abstract

Eudialyte is a group of hydrated silicate minerals essentially consisting of Na and Zr with a very complex crystal structure, and generally associated with alkaline rocks. The complexity of the eudialyte structure can be understood from the fact that Na alone exist in five distinct sites and extensive solid solubility can occur in almost all cation sites, sometimes one element occupying multiple sites to the extent of exclusion of other elements. Structurally, eudialyte can be represented as Na15[M 1 ]6[M 2]3Zr3[M 3 ](Si25O73)(O,OH,H2O)3X2 (Johnsen and Grice, 1999), where M 1 and M 2 sites are occupied by Ca, Mn and Fe, M 3 by Nb and X by OH, Cl and F. In addition, cations like Al, Hf, W, Ta, Sr, Ba and various REEs get incorporated into the eudialyte structure by substitution, and additional site vacancies even may develop in order to maintain electrical neutrality. Eudialyte, approximately of the composition Na9Ca8Mn3Nb(Zr,Ce)3Si25O73(OH)2, has hydrothermally replaced albite in the nepheline syenite gneiss exposed south of the Sushina hill of Purulia district, West Bengal. The eudialyte contains ≈2.25 atom% Zr and 0.75 atom% Nb. In addition to eudialyte in nepheline syenite, an unknown Na-Zr silicate (NZS) has also replaced the albite crystals. The NZS contains ≈ 7 atom% Zr with a possible empirical formula of Na12Zr11Si36O95(OH)10. Surface exposures of these rocks are limited at Sushina hill, yet a detailed and systematic investigation on this enigmatic rock is warranted for they may turn out to be a resource for Zr.

This is a preview of subscription content, access via your institution.

References

  1. Bhattacharyya, C. and Chaudhuri, K. (1986) Foid syenites and sodic schists from Sushina Hill, Purulia District, West Bengal. Indian Jour. Earth Sci., v.13(4), pp.339–342.

    Google Scholar 

  2. Chakrabarty, A. (2009) Petrogenesis of Carbonatite and Associated Alkaline Rocks, Purulia, W.B., India. Unpubld. Ph.D. Thesis, Dept. of Earth Sciences, IIT Roorkee, Roorkee.

    Google Scholar 

  3. Dunn, J.A. and Dey, A.K. (1942) The geology and petrology of eastern Singhbhum and surrounding areas. Mem. Geol. Surv. India, v.69, pp.281–450.

    Google Scholar 

  4. Johnsen, O. and Gault, R.A. (1997) Chemical variation in eudialyte. Neues Jahrb. Mineral., Abh., v.171, pp.215–237.

    Google Scholar 

  5. Johnsen, O. and Grice, J.D. (1999) The crystal chemistry of the eudialyte group. Can. Min., v.37, pp.865–891.

    Google Scholar 

  6. Johnsen, O., Ferraris, G., Gault, R.A., Grice, J.D., Kampf, A.R. and Pekov, I.V. (2003) The nomenclature of eudialyte-group minerals. Can. Min., v.43, pp.785–794.

    Article  Google Scholar 

  7. Johnsen, O., Grice, J.D. and Gault, R.A. (1998) Kentbrooksite from the Kangerdlugssuaq intrusion, East Greenland, a new Mn-REE-Nb-F end-member in a series within the eudialyte group: description and crystal structure. European Jour. Mineral., v.10, pp.207–219.

    Google Scholar 

  8. Kogarko, L.N. (1987) Alkaline rocks of the eastern part of the Baltic Shield (Kola Peninsula). In: J.G. Fitton and B.G.J. Upton (Eds.), Alkaline Igneous Rocks. Geol. Soc. Spec. Publ., v.30, pp.531–544.

  9. Larsen, M. and Sørensen, H. (1987) The Ilímaussaq intrusionprogressive crystallization and formation of layering in an agpaitic magma. In: In: J.G. Fitton and B.G.J. Upton (Eds.), Alkaline Igneous Rocks. Geol. Soc. Spec. Publ., v.30, pp.473–488.

  10. Marino, A.N. (1989) Economic geology of rare earth minerals. In: B.R. Lipin and G.A. McKay (Eds.), Geochemistry and Mineralogy of Rare Earth Elements. Rev. Mineral., v.21, pp. 309–337.

  11. Mitchell, R.H. and Liferovich, R.P. (2006) Subsolidus deuteric/hydrothermal alteration of eudialyte in lujavrite from the Pilansberg alkaline complex, South Africa. Lithos, v.91, pp.352–372.

    Google Scholar 

  12. Olivo, G.R. and Jones, A.E.W. (1999) Hydrothermal REE-rich eudialyte from the Pilanesberg complex, South Africa. Can. Min., v.37, pp.653–663.

    Google Scholar 

  13. Schönenberger, J. and Markl, G. (2008) The Magmatic and Fluid Evolution of the Motzfeldt Intrusion in South Greenland: Insights into the Formation of Agpaitic and Miaskitic Rocks. Jour. Petrol., v.49, pp.1549–1577.

    Article  Google Scholar 

  14. Sørensen, H. (1974) Alakli syenites, feldspathoidal syenites and related lavas. In: H. Sørensen (Ed.), The Alkaline Rocks. John Wiley and Sons, New York, pp.22–52.

    Google Scholar 

  15. Stromeyer, F. (1819) Summary of meeting 16 December 1819 [Fossilien...] Göttingische gelehrte Anziegen 3, 1993–2003.

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Amit Kumar Sen.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Chakrabarty, A., Pruseth, K.L. & Sen, A.K. First report of eudialyte occurrence from the Sushina hill region, Purulia district, West Bengal. J Geol Soc India 77, 12–16 (2011). https://doi.org/10.1007/s12594-011-0003-x

Download citation

Keywords

  • Eudialyte
  • Na-Zr silicate (NZS)
  • Agpaitic nepheline syenite
  • Sushina Hill