Comunicações Geológicas

  Previous Article | Back to Volume | Next Article
  Abstract | References | Citation | Download | Preview | Statistics
Sample volume 1
Title Occurrence and Origin of Alluvial Xenotime from Central Eastern Portugal (Central Iberian Zone/Ossa-Morena Zone)
Author D. Rosa, R. Salgueiro, C. Inverno, D. de Oliveira, F. Guimaraes
Trace amounts of alluvial xenotime (YPO4) were identified in black sands from pan concentrates collected during a rare earth reconnaissance survey, carried by the Instituto Geológico e Mineiro (IGM) in Central Eastern Portugal. The xenotime occurs as sub-rounded grains with an average size of ≈ 250 mm, and its identification was confirmed through XRD methods and EPMA analysis. It is believed that xenotime is more abundant than normally recognized and therefore frequently overlooked. The largest concentrations of this mineral occur in Nisa, António das Areias and Marvão. The regional geology and the accompanying mineral suite suggest xenotime originates from the granitic massifs of Nisa and Penamacor as well as the Beira Baixa Arkoses and levels of Plio-Pleistocene gravels interspersed with sandy clay. Although its economic interest is presently limited, its demand may increase as a result of the potential use of yttrium in the manufacturing of superconductors that are stable at ambient temperature.
Gaines, R.V., Skinner, H.C.W., Ford E.E., Mason B. & Rosenzweig, A. (1997) – Dana’s New Mineralogy, 8th Edition, Wiley Interscience, 1872 p.

Hammond, C.R. (1997) – CRC Handbook of Chemistry and Physics, 78th Edition. David R. Lide, Editor in Chief.

Inverno, C.M.C., Oliveira, D.P.S. & Rodrigues, L., (colaboração de: Viegas, L., Matos, J., Martins, L., Salgueiro, R., Lencastre, J., Farinha, J., Rosa, D., Chichorro, M., Santana, H., Oliveira, V., Fernandes, J. & Pateiro, R.) (2007) – Inventariação e prospecção de terras raras nas regiões fronteiriças da Beira Baixa e do Norte Alentejo: Alfragide, INETI, Internal Report, 2982 p.

Inverno, C.M.C., Oliveira, D.P.S., Viegas, L.F.S., Lencastre, J.P.B. & Salgueiro, R.M.M. (1998) – REE-enriched Ordovician quartzites in Vale de Cavalos, Portalegre, Portugal: Proceedings Volume of GeoCongress’98, Pretória, Jul.1998, Geological Society of South Africa, p. 153-157.

JCPDS (1980) – Mineral Powder Diffraction File Data Book. Joint Committee on Powder Diffraction Standards – International Centre for Diffraction Data, Pennsylvania, USA.

Kositcin, N., McNaughton, N.J., Griffin, B.J., Fletcher, I.R., Groves, D.I. & Rasmussen, B. (2003) – Textural and geochemical discrimination between xenotime of different origin in the Archean Witwatersrand Basin, South Africa. Geochimica et Cosmochimica Acta, 67, p. 701-731.

Larsen, A.O. (1996) – Rare earth minerals from the syenite pegmatites in the Oslo Region, Norway, in Jones, A. P., Wall, F., and Williams, C.T., eds, Rare Earth Minerals – Chemistry, origin and ore deposits. The Mineralogical Society Series, nr. 7, Chapman & Hall; London, U.K., p 151-166.

Morrison, G. (1999) – Superconductor power up, Mechanical Engineering Magazine, January 1999 issue.

Oliveira, J.T., Pereira, E., Ramalho, M., Antunes, M.T. & Monteiro, J.H. (compilers) (1992) – Carta Geológica de Portugal, 1: 500 000, Serviços Geológicos de Portugal, Lisboa.

Parfenoff, A., Pomerol, C., & Toureno, J. (1970) – Les Minéraux en Grains – Méthodes d’étude et Détermination. Paris, Masson et Cie, Éditeurs, 571 p.

Rasmussen, B. (1996) – Early-Diagenetic REE-phosphate minerals (florencite, gorceixite, crandalite, and xenotime) in marine sandstones: a major sink for oceanic phosphorus. American Journal of Science, 296, p. 601-632.

Subrahmanyam A.V., Desapati, T., Anil Kumar V., Deshmukh, R.D. & Viswanathan G. (2004) – Occurrence of xenotime in the Narasapur beach placers, West Godavari District, Current Science, 87-10, p. 1458-1461.

USGS (2010) – United States Geological Survey Mineral Commodity Summaries – Yttrium, January 2010.
Keywords Xenotime, alluvial, rare earths, CIZ/OMZ.
Download Full PDF Download
  Previous Article | Back to Volume | Next Article
Search in articles
Journal Published articles
CG 38
Journal Hits
CG 98341
Journal Downloads
CG 287
Total users online -