Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-02T19:22:06.318Z Has data issue: false hasContentIssue false
  • English
  • Français

Composition of priderite in phlogopitites from the Catalão I carbonatite complex, Brazil

Published online by Cambridge University Press:  05 July 2018

José C. Gaspar ,
Antônio J. G. Conceição e Silva  and
Débora P. de Araújo
José C. Gaspar
Affiliation:
Departamento de Mineralogia e Petrologia, Instituto de Geociências, Universidade de Brasília, 70910-900 Brasilia D.F., Brazil
Antônio J. G. Conceição e Silva
Affiliation:
Departamento de Mineralogia e Petrologia, Instituto de Geociências, Universidade de Brasília, 70910-900 Brasilia D.F., Brazil
Débora P. de Araújo
Affiliation:
Departamento de Mineralogia e Petrologia, Instituto de Geociências, Universidade de Brasília, 70910-900 Brasilia D.F., Brazil
Get access Rights & Permissions [Opens in a new window]

Abstract

Magnetite grains with exsolved ilmenite lamellae may be replaced by pyrite or carbonate in phlogopitites of the Catalão I carbonatite complex, Goiás State, Brazil. The ilmenite is transformed in part to priderite and sometimes to rutile. Priderite occurs as small anhedral grains (< 0.2mm) or composite crystals associated with ilmenite and rutile. Chalcopyrite, magnetite, monazite, and pyrochlore also occur inside the area of original magnetite grains. The priderite belongs to the K2FeTi7O16-BaFeTi7O16 series with K/(K + Ba) ranging from 1.0 to 0.53. The highest contents for other elements are: V2O3 2.65, Cr2O3 4.1, and Nb2O5 1.98 wt.%. Priderites associated with magnetite have the highest V, Cr, and Nb contents whereas others have the highest Ba content. Zoning characterized by K-Ba substitution is patchy but always present. V-and Cr-poor priderites are similar in composition to priderites from lamproites, and the V- and Cr-rich ones are compositionally similar to hollandite-group minerals found in kimberlites.

Keywords

prideritecarbonatitephlogopiteilmeniteBrazil
Type
Mineralogy
Information
Mineralogical Magazine , Volume 58 , Issue 392 , September 1994 , pp. 409 - 415
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1994

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.)

References

Araujo, D. P. and Gaspar, J. C. (1992) Quimica mineral dos carbonatitos e rochas associadas de Catalao I -GO. Boletim de Resumos Expandidos. 37” Congresso Brasileiro de Geologia, Sao Paulo, 2, 90–91.Google Scholar
Araujo, D. P. and Gaspar, J. C. (1993) Fe3+ no sitio tetraedrico de flogopitas das rochas do complexo carbonatitico de Catalao I, Brasil. Volume de Resumos Expandidos. IV Congresso Brasileiro de Geoquimica, Brasilia, 62—63.Google Scholar
Baecker, M. L. (1983) A mineralizacao de niobio do solo residual lateritico e a petrografia das rochas ultramaficas-alcalinas do Domo de Catalao I, Goias. Dissertacao de Mestrado. Universidade de Brasilia.Google Scholar
Carvalho, W. T. (1974) Aspectos geologicos e petrograficos do Complexo Ultramafico-alcalino de Catalao I, GO. Anais XXVIII Cong. Bras. Geol, SGB, 107-23Google Scholar
Danni, J. C. M., Baecker, M. L. and Ribeiro, C. C. (1991) The geology of the Catalao I carbonatite complex. In Field Guide Book. Fifth International Kimberlite Conference, (Leonardos, O. H., Meyer, H. O. A. and Gaspar, J. C., eds.), 25-30.Google Scholar
Gaspar, J. C. and Adusumilli, M. S. (1976) Sobre os carbonatitos de Catalao I, Goias. Bol. Min, 4, 5–22.Google Scholar
Gierth, E., Goldmann, D., Leonardos, O. H. and Baecker, M. L. (1985) Main features of the paragenetic evolution of Catalao I, Goias, Brazil. Geol. Paleont., Teil I, 9/10, 1469–75.Google Scholar
Gierth, E. and Leonardos, O. H. (1989) Some characteristics of the niobium ores in the unweathered sections of the carbonatite complexes Catalao I and II, Goias, Brazil. 79th Annual Meeting of the Geologische Vereinigung, Terra Abstracts, 1, 1–2.Google Scholar
Hasui, U. and Cordani, U. G. (1968) Idades de potassio-argonio de rochas eruptivas mesozoicas do Oeste Mineiro e do Sul de Goias. Anais XXI Congresso Brasileiro de Geologia S.B.G., Belo Horizonte, 139-43.Google Scholar
Jaques, A. L., Lewis, J. D. and Smith, C. B. (1986) The kimberlites and lamproites of Western Australia. Geological Survey of Western Australia, Bulletin 132.Google Scholar
Mitchell, R. H. (1985) A review of the mineralogy of lamproites. Trans. Geol. Soc. South Africa, 88, 411–37.Google Scholar
Mitchell, R. H. (1991) Accessory rare earth, strontium, barium and zirconium minerals in the Benfontein and Wesselton calcite kimberlites, South Africa. In Proceedings of the 5th International Kimberlite Conference. (Meyer, H. O. A. and Leonardos, O. H., eds.) In press.Google Scholar
Mitchell, R. H. and Bergman, S. C. (1991) Petrology of Lamproites. Plenum Press. Mitchell, R. H. and Haggerty, S. E. (1986) A new K-V-Ba titanite related to priderite from the New Elands kimberlite, South Africa. Neues. Jahrb. Mineral. Mh., 1986(8), 376-84.Google Scholar
Mitchell, R. H. and Lewis, R. D. (1983) Priderite-bearing xenoliths from the Prairie Creek mica peridotite, Arkansas. Canad. Mineral., 21, 59–64.Google Scholar
Mitchell, R. H. and Meyer, H. O. (1989) Niobian K-Ba-V titanates from micaceous kimberlite, Star 1993: mine, Orange Free State, South Africa. 1993] Mag., 53, 451–6.Google Scholar