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Petrogenetic implication of the Mössbauer hyperfine parameters of Fe3+-chromites from Sukinda (India) ultramafites

Published online by Cambridge University Press:  05 July 2018

Sachinath Mitra
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta 700032, India
Tapan Pal
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta 700032, India
Taraknath Pal
Affiliation:
Department of Geological Sciences, Jadavpur University, Calcutta 700032, India

Abstract

Chromites from two horizons of the Sukinda area (India) marked as ‘grey ore’ and ‘brown ore’ zones have been studied by 57Fe Mössbauer spectroscopy, which revealed that both chromite types are oxidised and have a type of disordered spinel structure in which octahedral sites are occupied by Fe2+ ions.

The spectra of the grey ore sample can be fitted to three doublets corresponding to Fe2+ (A), Fe3+ (A) and Fe2+ (B) sites. This sample is less oxidised than the brown ore, in which progressive oxidation in the magmatic (?) stage led to the complete conversion of Fe2+ in A sites to Fe3+. The spectra of the brown ore are characterised by two doublets correpsonding to two tetrahedral (A) sites of Fe3+ with different next-nearest neighbour configurations and a third doublet for Fe2+ at the B site. The brown ores have higher chromium and Fe3+ content and have lesser amounts of Ni and Al in comparison to the grey ores. Megascopically, the former shows larger crystal sizes. The high Fe3+ content in the brown ore suggests that this type of chromite was formed in a region of high ƒO2 in the magmatic environment. This perhaps occurred at the part of the mantle where the temperature was higher and the rate of cooling was slower than that of the grey ores which crystallised in the magmatic melt.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1991

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References

Arculus, R. J. and Delano, J. W. (1981) Intrinsic oxygen fugacity measurements: techniques and results for spinels from upper mantle peridotites and megacryst assemblages. Geochim. Cosmochim. Ada, 45, 899913.CrossRefGoogle Scholar
Arculus, R. J. Dawson, J. B., Mitchell, R. H., Gust, D. A., and Holmes, R. D. (1984) Oxidation states of the upper mantle recorded by megacryst ilmenite in kimberlite and type A and B spinel Iherzolites. Contrib. Mineral. Petrol, 85, 8594.CrossRefGoogle Scholar
Banerjee, S. K., O'Reilly, W., Gibb, T. C., and Greenwood, N. N. (1969) The behaviour of ferrous ions in iron-titanium spinels. J. Phys. Chem. Solids, 28, 1323–35.CrossRefGoogle Scholar
Bancroft, G. M., Osborne, M. D., and Fleet, M. E. (1983) Next-nearest neighbour effects in the Mossbauer spectra of Cr-spinels: an application of partial quadrupole splitting. Solid State Comm., 47(8), 623-5.CrossRefGoogle Scholar
Canil, D., Virgo, D., and Scarfe, C. M. (1988) Oxidation state of spinel lherzolite xenoliths from British Columbia: a 57Fe Mossbauer investigation. Ann. Rept. Geophys. Lab., Carnegie Inst. Washington (1987-1988) No. 2102, 18-22.Google Scholar
Dyar, M. D., McGuire, A. V., and Ziegler, R. D. (1989) Redox equilibria and crystal chemistry of coexisting minerals from spinel lherzolite mantle xenoliths. Am. Mineral., 74, 969–80.Google Scholar
Engin, T. and Hirst, D. M. (1970) The Alpine chrome ores of the Audizlik-Zinparalik area, Fethiye, S.W. Turkey. Trans. Inst. Min. Metall, 79B, 1629.Google Scholar
Fatseas, G. A., Dormann, J. L., and Blanchard, H. (1976) Study of the Fe3+/Fe2+ ratio in natural chromites (FexMg1-x)(Cr1-y-zFeyAlz)O4 J. Phys., 12, 787–92.Google Scholar
Galvao Da Silva, E., Aloras, A., and Sette Camara, A. O. R. (1976) Mössbauer effect study of cation distribution in natural chromites. Ibid., 12, 783-5.Google Scholar
Galvao Da Silva, E., and Speziali, N. Z. (1980) Mossbauer effect study of natural chromites of Brazilian and Philippine origin. Appl. Phys., 22, 389–92.CrossRefGoogle Scholar
Gillot, B., Delafosse, D., and Barret, P. (1973) Oxidation menagee du chromite de fer stoechiometri-que a basse temperature, reduction du compose obtenu. Mat. Res. Bull., 8, 1431–12.CrossRefGoogle Scholar
Gillot, B., Chassagneux, F., and Rousset, A. (1981) Oxidation in the y-phase of spinels containing iron. II: influence of defects on the oxidation kinetics and electrical properties. J. Solid State Chem., 38, 219–28.CrossRefGoogle Scholar
Jensen, S. D. and Shive, P. N. (1973) Cation distribution in sintered titanomagnetites. J. Geophys. Res., 78, 8474–80.CrossRefGoogle Scholar
Leider, H. R. and Pipkorn, D. N. (1968) Mossbauer effect in MgO:Fe2+; low-temperature quadrupole splitting. Phys. Rev., 165(2), 494500.CrossRefGoogle Scholar
Marshall, L. and Dollase, W. (1984) Cation arrange-ment in Fe-Zn-Cr spinel oxides. Am. Mineral, 69, 928–36.Google Scholar
Mitra, S. (1960) Chromite occurrence around Saruabil, Cuttack, Dt. Orissa. Indian Minerals, 14(4), 347-60.Google Scholar
Mitra, S. (1973) Orthopyroxenes from Sukinda ultramafites and the nature of the parental magma. Ada. Min. Pet. (Szeged), 21(1), 87106.Google Scholar
Mitra, S. (1976a) Mossbauer study of orthopyroxenes from Sukinda, Orissa, India. Neues Jahrb. Mineral. Mh., 169-73.Google Scholar
Mitra, S. (1976b) Compositional variations in chromites from Sukinda, Orissa, India. J. Geol. Soc. India, 17(2), 224-35.Google Scholar
Mizoguchi, T. and Tanaka, M. (1963) The nuclear quadrupole interaction of 57Fe in spinel type oxides. Phys. Soc. Japan, 18, 1301–6.CrossRefGoogle Scholar
Nolet, D. A. and Burns, R. G. (1979) Ilvaite: a study of temperature dependent electron delocalisation by the Mössbauer effect. Phys. Chem. Minerals, 4, 221–34.CrossRefGoogle Scholar
Osborne, M. D. (1984) Next-nearest neighbour effects in the Mossbauer spectra of (Cr, Al) spinels. J. Solid State Chem., 53, 174–83.CrossRefGoogle Scholar
Osborne, M. D. Fleet, M. E., and Bancroft, G. M. (1981) Fe2+-Fe3+ ordering in chromite and Cr-bearing spinels. Contrib. Mineral. Petrol, 77, 251–5.CrossRefGoogle Scholar
Readman, P. W. and O'Reilly, W. (1972) Magnetic properties of oxidised (cation deficient) titanomagnetites (Fe, Ti, ☐)3O4. J. Geomagn. Geoelectr., 24, 6990.CrossRefGoogle Scholar
Robbins, M., Wertheim, G. K., Sherwood, R. C., and Buchanan, D. N. E. (1971) Magnetic properties and site distributions in the system FeCr2O4-Fe3O4-(Fe2+Cr2-xFex 3+O4). J. Phys. Chem. Solids,’ 32, 717–29.CrossRefGoogle Scholar
Schmidbauer, E. (1987) 57Fe Mossbauer spectroscopy and magnetisation of cation deficient Fe TiO4 and FeCr2O4. Part II: magnetisation data. Phys. Chem. Minerals, 15, 201207.CrossRefGoogle Scholar
Shinno, I. (1981) A Mossbauer study of ferric iron in olivine. Phys. Chem. Minerals, 7, 9195.CrossRefGoogle Scholar
Singh, A. K., Jain, B. K., Date, S. K., and Chandra, K. (1978) Structural and compositional study of natural chromites of Indian origin. Appl. Phys., 11, 769–76.Google Scholar
Virgo, D., Luth, R. W., Moats, M. A., and Gene, C. U. (1988) Constraints on the oxidation state of the mantle: an electrochemical and 57Fe Mossbauer study of mantle-derived ilmenites. Geochim. Cosmochim. Ada, 52, 1781–94.CrossRefGoogle Scholar
Zhe, L., Mingzhi, J., Wei, H., and Milan, L. (1988) Next-nearest neighbour effect in chromite. Hf. Int., 41, 819–22.Google Scholar