Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-22T13:48:36.330Z Has data issue: false hasContentIssue false
  • English
  • Français

Differential REE uptake by sector growth of monazite

Published online by Cambridge University Press:  05 July 2018

G. Cressey ,
F. Wall  and
B. A. Cressey
G. Cressey
Affiliation:
Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
F. Wall
Affiliation:
Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
B. A. Cressey
Affiliation:
School of Ocean and Earth Science, Southampton Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

Monazite-(Ce) from a dolomite carbonatite at Kangankunde, Malawi, is sector-zoned with variation in La2O3 of up to 6.0 wt.% and in Nd2O3 of up to 3.9 wt.% between sectors. Single crystal X-ray diffraction, backscattered electron imaging and microprobe analysis have been used to establish the relationship between the morphology and sector chemistry of this low-Th monazite, (Ce,La,Nd)PO4. Uptake of La by {011} sector surfaces is enhanced relative to that of and {100} sectors; Ce shows no partitioning differences; and uptake of Nd is more easily facilitated on and {100} surfaces relative to {011}. There appears to be a distinct relationship between the size of the REE ion and the probability of uptake via the different growth surfaces. Interpretation of this uptake behaviour, based on theories involving ‘protosites’, involves an investigation of the possible kink site geometries at edge-steps during growth. Part-formed kink sites with small entrance sizes are calculated to occur with higher frequency on relative to {011}, and this correlates with an increase in the smaller-sized REE (Nd) uptake by growth surfaces. The overall morphology and sector growth is suggested to be a function of uptake chemistry.

Keywords

monazitesector-zoningcrystal growthREEcarbonatiteKangankunde
Type
Research Article
Information
Mineralogical Magazine , Volume 63 , Issue 6 , December 1999 , pp. 813 - 828
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1999

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

Burt, D.M. (1989) Compositional and phase relations among rare earth elements. In Geochemistry and mineralogy of rare earth elements (Lipin, B.R. and McKay, G.A., eds). Reviews in Mineralogy, 21, Mineralogical Society of America, pp. 259–307.CrossRefGoogle Scholar
Chernov, A.A. (1984) Modern Crystallography III. Springer-Verlag, Berlin.CrossRefGoogle Scholar
Clark, A.M. (1993) Hey's Mineral Index. Chapman & Hall, London, 851 pp.Google Scholar
Dowty, E. (1976) Crystal structure and crystal growth: II. Sector zoning in minerals. Amer. Mineral., 61, 460–9.Google Scholar
Dowty, E. (1980) Computing and drawing crystal shapes. Amer. Mineral., 65, 465–71.Google Scholar
Förster, H.-J. and Harlov, D.E. (1999) Monazite(Ce)- huttonite solid solutions in granulite-facies metaba- sites from the Ivrea-Verbano Zone, Italy. Mineral. Mag., 63, 587–94.CrossRefGoogle Scholar
Fouke, B.W. and Reeder, R.J. (1992) Surface structural controls on dolomite composition. Geochim. Cosmochim Acta, 56, 4015–24.CrossRefGoogle Scholar
Garson, M.S. (1966) Carbonatites in Malawi. In Carbonatites (Tuttle, O.F. and Gittins, J., eds). Wiley, London, pp. 33–71.Google Scholar
Garson, M.S. and Campbell-Smith, W. (1965) Carbonatite and agglomeratic vents in the Western Shire Valley. Geological Survey of Malawi, Memoir no. 3, Government Press, Zomba, Malawi.Google Scholar
Hollister, L.S. (1970) Origin, mechanism, and consequences of compositional sector-zoning in staurolite. Mineral. Mag., 55, 742–66.Google Scholar
Holt, D.N. (1965) The Kangankunde Hill rare earth prospect. Results of an economic investigation. Malawi Ministry of Natural Resouces, Geological Survey Department, Bulletin 20, Government Press, Zomba, 130 p.Google Scholar
Kapustin, Yu. L. (1980) Mineralogy of carbonatites. Amerind Publishing, New Delhi, 259 p. (Translated from Russian: Mineralogiya Karbonatitov, 1971) Nauka Publishers, Moscow.Google Scholar
Kostov, I. (1968) Mineralogy. Oliver and Boyd.Google Scholar
Le Bas, M.J. (1989) Diversification of carbonatite. In Carbonatites: genesis and evolution (Bell, K., ed.). Unwin Hyman, London, pp. 428–47.Google Scholar
Nakamura, Y. (1973) Origin of sector-zoning of igneous clinopyroxenes. Amer. Mineral., 58, 986–90.Google Scholar
Ni, Y., Hughes, J.M. and Mariano, A.N. (1995) The crystal chemistry of monazite and xenotime structures. Amer. Mineral., 80, 21–6.CrossRefGoogle Scholar
Overstreet, W.C. (1967) The geologic occurrence of monazite. USGS Prof. paper, 530, 1–327.Google Scholar
Paquette, J. and Reeder, R.J. (1995) Relationship between surface structure, growth mechanism, and trace element incorporation in calcite. Geochim. Cosmochim. Acta, 59, 735–49.CrossRefGoogle Scholar
Pina, C.M., Becker, U., Risthaus, P., Bosbach, D. and Putnis, A. (1998) Molecular-scale mechanisms of crystal growth in barite. Nature, 395, 483–6.CrossRefGoogle Scholar
Rakovan, J. and Reeder, R.J. (1994) Differential incorporation of trace elements and dissymmetrization in apatite: The role of surface structure during growth. Amer. Mineral., 79, 892–903.Google Scholar
Rakovan, J. and Reeder, R.J. (1996) Intracrystalline rare earth element distributions in apatite: Surface structural influences on incorporation during growth. Geochim. Cosmochim. Acta, 60, 4435–45.CrossRefGoogle Scholar
Rakovan, J., McDaniel, D.K. and Reeder, R.J. (1997) Use of surface-controlled REE sectoral zoning in apatite from Llallagua, Bolivia, to determine a single-crystal Sm-Nd age. Earth Planet. Sci. Lett., 146, 329–36.CrossRefGoogle Scholar
Reeder, R.J. and Paquette, J. (1989) Sector zoning in natural and synthetic calcites. Sedim. Geol., 65, 239–47.CrossRefGoogle Scholar
Reeder, R.J. and Prosky, J.L. (1986) Compositional sector zoning in dolomite. J. Sed. Petrol., 56, 237–47.Google Scholar
Roberts, W.L., Campbell, T.J. Jr. and Rapp, G.R. (1990) Encyclopedia of minerals. 2nd edition, Van Nostrand Reinhold Company, New York, 979 p.CrossRefGoogle Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr., A32, 751–67.CrossRefGoogle Scholar
Staudt, W.J., Reeder, R.J. and Schoonen, M.A.A. (1994) Surface structural controls on compositional zoning of SO4 and SeO4 in synthetic calcite single crystals. Geochim. Cosmochim. Acta, 58, 2087–98.CrossRefGoogle Scholar
Sunagawa, I. (1984) Growth of crystals in nature. In Materials Science of the Earth's Interior (Sunagawa, I., ed.). Terra Scientific, Tokyo, pp. 63–105.Google Scholar
Sunagawa, I. (1987) Morphology of minerals. In Morphology of Crystals (Sunagawa, I., ed.). Terra Scientific, Tokyo, pp. 509–87.Google Scholar
Titiloye, J.O., Parker, S.C. and Mann, S. (1993) Atomistic simulation of calcite surfaces and the influence of growth additives on their morphology. J. Cryst. Growth, 131, 533–45.CrossRefGoogle Scholar
Wall, F. and Mariano, A.N. (1996) Rare earth minerals in carbonatites: a discussion centred on the Kangankunde Carbonatite, Malawi. In Rare earthminerals: chemistry, origin and ore deposits (Jones, A.P., Wall, F. and Williams, T.C., eds). Mineralogical Society Series, 7, Chapman & Hall, London, pp. 193–225.Google Scholar
Watson, E.B. (1996) Surface enrichment and trace- element uptake during crystal growth. Geochim. Cosmochim. Acta, 60, 5013–20.CrossRefGoogle Scholar
Watson, E.B. and Liang, Y. (1995) A simple model for sector zoning in slowly grown crystals: Implications for growth rate and lattice diffusion, with emphasis on accessory minerals in crustal rocks. Amer. Mineral., 80, 1179–87.CrossRefGoogle Scholar
Wilken, G. (1977) Surface features of synthetic silicate garnets. J. Cryst. Growth, 40, 165–8.CrossRefGoogle Scholar
Woolley, A.R. (1991) The Chilwa alkaline igneous province of Malawi: a review. In Magmatism in Extensional Structural Settings. The Phanerozoic African Plate (Kampunzu, A.B. and Lubala, R.T., eds). Springer-Verlag, Berlin, pp. 377–409.CrossRefGoogle Scholar
Wyckoff, R.W.G.(1965) Crystal Structures, 2nd ed., Vol 3. Interscience, New York.Google Scholar