Mineralogy and Petrology

, Volume 55, Issue 1–3, pp 53–69 | Cite as

Nb-Ta-minerals from the cap de creus pegmatite field, eastern Pyrenees: distribution and geochemical trends

  • P. Alfonso Abella
  • J. -C. Melgarejo i Draper
  • M. Corbella i Cordomi
Article

Summary

Internal structure and mineralogy facilitate distinction of four main pegmatite types at the eastern end of the Pyrenees. Three main trends in compositional variations in Nb-Ta-Sn-REE-Ti minerals have been established: a regional trend, with Ta/(Ta + Nb) ratio increasing towards the more evolved pegmatites, Mn/(Mn + Fe) being relatively low and increasing only slightly; a single-body trend, with similar enrichment toward the late pegmatite units; a single-crystal trend, with zoning related to both Ta/(Ta + Nb) and Mn/(Mn + Fe) ratios and a tendency toward Ta-enrichment in the late growth stages. The regional geochemical enrichment trends in the Mn/(Mn + Fe) ratios and Ta/(Ta + Nb) are those expected for a beryl-columbite pegmatite type. In a single pegmatite, the evolution depends on the simultaneous growth of other mineral species. Three factors seem to control the development of zoning in columbite-tantalite crystals: availability of Mn, Ta, Fe, Nb, significant differences in solubility between mineral group end members and re-equilibria with late pegmatite fluids.

Keywords

Pyrenees Regional Trend Simultaneous Growth Late Growth Stage Similar Enrichment 

Nb-Ta-Minerale aus dem Pegmatit-Feld vom Cap de Creus, östliche Pyrenäen: Verteilung und geochemische Trends

Zusammenfassung

Am Ostrand der Pyrenäen können anhand des inneren Aufbaus und der Mineralogie vier Haupttypen von Pegmatiten unterschieden werden. Die Zusammensetzungen von Nb-Ta-Sn-SEE-Ti-Mineralen folgen drei Haupttrends: einem regionalen Trend, bei dem das Verhältnis Ta/(Ta + Nb) zu den höher entwickelten Pegmatiten hin zunimmt, während Mn/(Mn + Fe) relativ niedrig ist und nur leicht zunimmt; einem lokalen (auf das jeweilige Vorkommen beschränkten) Trend mit einer ähnlichen Anreicherung zu den spätpegmatitischen Einheiten hin; einem auf Einzelkristalle bezogenen Trend mit Zonierung in bezug auf die Verhältnisse Ta/(Ta + Nb) und Mn/(Mn + Fe) und einer Tendenz zur T a-Anreicherung in den späten Wachstumsphasen. Die regionalen geochemischen Anreicherungstrends in den Mn/(Mn + Fe)- und Ta/(Ta + Nb)-Verhältnissen entsprechen jenen, wie sie für den Beryll-Columbit-Pegmatit-Typ erwartet werden. In einem einzelnen Pegmatit hängt die Entwicklung vom gleichzeitigen Wachstum anderer Mineral-Spezies ab. Drei Faktoren scheinen die Ausbildung einer Zonierung in Columbit-Tantalit-Kristallen zu kontrollieren: das Angebot an Mn, Ta, Fe und Nb, deutliche Unterschiede in der Löslichkeit der Endglieder von Mineralgruppen und die Iteequilibrierung mit spätpegmatitischen Lösungen.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Ayora C, Casas JM (1986) Strata-bound As-Au mineralization in pre-Caradocian rocks from the Vall de Ribes, Eastern Pyrenees, Spain. Mineral Deposita 21: 278–287Google Scholar
  2. Carreras J, Orta JM, San Miguel A (1975) El área pegmatitica del litoral N de la Península del Cap de Creus y su contexto metamòrfico y estructural. Rev Inv Geol Univ Barcelona 30: 11–34Google Scholar
  3. Carreras J, Casas JM (1987) On folding and shear zone development: a mesoscale structural study on the transition between two different tectonic styles. Tectonophysics 135: 87–98Google Scholar
  4. Cavet P (1957) Le Paléozoique de la zone axiale des Pyrénées Orientales françaises entre le Roussillon et l'Andorre. Bull Serv Carte Géol Fr 55, 254: 303–518Google Scholar
  5. Černý P (1982) Anatomy and classification of granitic pegmatites. In: Černý P (ed) Granitic pegmatites in science and industry. M A C Short Course Handbook 8: 1–40Google Scholar
  6. Černý P (1989) Characteristics of pegmatite deposits of tantalum. In:Möller P, Černý P, Saupé F (ed) Lanthanides, tantalum and niobium. Springer, Berlin Heidelberg New York Tokyo, pp195–239Google Scholar
  7. Černý P (1990) Distribution, affiliation and derivation of rare-element granitic pegmatites in the Canadian Shield. Geol Rundschau 79/2: 183–226Google Scholar
  8. Černý P (1991) Rare-element granitic pegmatites, part 1. Anatomy and internal evolution of pegmatite deposits. Geosc Canada 18, 2: 49–67Google Scholar
  9. Černý P, Turnock AC (1971) Niobium-Tantalum minerals from granitic pegmatites at Greer Lake, Southeastern Manitoba. Can Mineral 10: 755–772Google Scholar
  10. Černý P, Ercit TS (1989) Mineralogy of niobium and tantalum: crystal chemical relationships, paragenetic aspects and their economic implications. In:Möller P, Černý P, Saupé F (eds) Lanthanides, tantalium and niobium. Springer, Berlin Heidelberg New York Tokyo, pp27–79Google Scholar
  11. Černý P, Ercit TS (1985) Some recent advances in the mineralogy and geochemistry of Nb and Ta in rare-element granitic pegmatites. Bull Mineral 108: 499–532Google Scholar
  12. Černý P, Čech F, Povondra P (1964) Review of ilmenorutile-striiverite minerals. N Jb Mineral Abh 101: 142–172Google Scholar
  13. Černý P, Meintzer RE, Anderson AJ (1985) Extreme fractionation in rare-element granitic pegmatites: selected examples of data and mechanisms. Can Mineralogist 23: 381–421Google Scholar
  14. Černý P, Goad BE, Hawthorne FC, Chapman R (1986) Fractionation trends of the Nb- and Ta-bearing oxide minerals in the Greer Lake pegmatitec granite and its pegmatite aureole, southeastern Manitoba. Am Mineral 71: 501–517Google Scholar
  15. Černý P, Novák M, Chapman R (1992a) Effects of sillimanite-grade metamorphism and shearing on Nb-Ta oxide minerals in granitic pegmatites: Maršikov, Northern Moravia, Czechoslovakia. Can Mineral 30: 699–718Google Scholar
  16. Corbella M, Melgarejo JC (1990a) Rare-element pegmatites of the Cap de Creus Peninsula, Northeast Spain: a new field of the Beryl-Phosphate subtype. In: Taylor RP (ed) 8th Quadrennial IAGOD Symposium Volume, Ottawa 1990. E Schweizerbart śche Verlagsbuchhandlung, StuttgartGoogle Scholar
  17. Corbella M, Melgarejo JC (1990b) Caracteristicas y distribución de los fosfatos de las pegmatites graniticas de la Peninsula del Cap de Creus (Pirineo Oriental Catalán). Bol Soc Esp Min 13: 169–182Google Scholar
  18. Druguet E (1992) Petrologia del complex migmatitic de l'àrea de la Punta dels Furallons (Cap de Creus). Thesis, Universitat de Barcelona, 235 p (unpublished)Google Scholar
  19. Foord EE (1982) Minerals of Sn, Ti, Nb and Ta. In: Černý P (ed) Granitic pegmatites in science & industry. Mineral Assoc Canada, Short Course Handbook 8: 187–238Google Scholar
  20. Grice JD, Černý P, Ferguson RB (1972) The Tanco pegmatite at Bernic Lake, Manitoba. II. Wodginite, tantalite, pseudo-ixiolite and related minerals. Can Mineral 11: 609–642Google Scholar
  21. Jacobson R, Webb JS (1947) The occurrence of nigerite, a new tin mineral in quartzsillimanite rocks from Nigeria. Mineral Mag 28: 118–128Google Scholar
  22. Kloosterman JB (1974) Nigerite in the tin-tantalum pegmatites of Amapá, Brazil. Mineral Mag 39: 837–846Google Scholar
  23. oVon Knorring 0, Condliffe E (1984) On the occurrence of niobium-tantalum and other rare element minerals in the Meldon aplite, Devonshire. Mineral Mag 48: 443–448Google Scholar
  24. Lahti SI (1981) On the granitic pegmatites of the Eräjärvi area in Orivesi, Southern Finland. Geol Surv Finland Bull 314: 82 pGoogle Scholar
  25. Lahti SI (1987) Zoning in columbite-tantalite crystals from the granitic pegmatites of the Erdjdrvi area, Southern Finland. Geochim Cosmochim Acta 51: 509–517Google Scholar
  26. Putnis A, Fernández-Díaz L, Prieto M (1992) Experimentally produced oscillatory zoning in the (Ba,Sr)SO4 solid solution. Nature 358: 743–745Google Scholar
  27. Spilde MN, Shearer ChK (1992) A comparison of tantalum-niobium oxide assemblages in two mineralogically distinct rare-element granitic pegmatites, Black hills, South Dakota. Can Mineral 30: 719–737Google Scholar
  28. Uher H (1991) Be-Nb-Ta Granitic pegmatites- a new type of rare-element mineralization in the western Carpathians. Geol Carpathica 42, 6: 331–339Google Scholar
  29. Wise M, Turnock AC, Černý P (1985) Improved unit cell dimensions for ordered columbitetantalite end members. N Jb Mineral Mh 8: 372–378Google Scholar
  30. Wise MA (1987) Geochemistry and crystal chemistry of Nb, Ta and Sn Minerals from the Yellowknife Pegmatite Field, N.W.T. Thesis, University of Manitoba, 326 p (unpublished)Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • P. Alfonso Abella
    • 1
  • J. -C. Melgarejo i Draper
    • 1
  • M. Corbella i Cordomi
    • 1
  1. 1.Departament de Cristallografia Mineralogia i Dipòsits MineralsUniversitat de BarcelonaBarcelonaSpain

Personalised recommendations