Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-02T20:27:05.505Z Has data issue: false hasContentIssue false

Chemical and morphological variation in tourmalines from the Hub Kapong batholith of peninsular Thailand

Published online by Cambridge University Press:  05 July 2018

D. A. C. Manning*
Affiliation:
Department of Geology, The University, Manchester M13 9PL

Abstract

Electron probe microanalysis of tourmaline from late-stage aplites and mineralized (Sn-W) pegmatites from the Hub Kapong batholith of peninsular Thailand has revealed considerable chemical variation, and has shown that skeletal tourmaline crystals predominate within the pegmatites. The tourmalines show substitution towards the schorl end-member of the schorl-dravite series, as well as substitution towards alkali-free or proton deficient tourmaline. The extent of both substitutions increases (a) from aplites to pegmatites and (b) from core to rim within a single grain and so is believed to become greater with increasing degrees of differentiation of the aplite-pegmatite system. The development of skeletal crystals within the pegmatites and non-skeletal crystals within the aplites is believed to be due to the different kinetics of crystal growth obtaining within a hydrous, pegmatitic, fluid (viz. heterogeneous nucleation and comparatively rapid crystal growth rates) which in turn arise from differences in the structure of the aplitic magma and pegmatitic fluid. The observed chemical and morphological variation shown by the tourmalines is used to discuss the petrogenesis of the aplites and pegmatites, and associated ore deposits. During differentiation, the volatile content of the aplite magmas increased, leading to water saturation and the separation of a hydrous pegmatitic fluid. After a period of coexistence, possibly in chemical equilibrium, the crystallization of the pegmatites continued once the aplite magma had completely consolidated.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1982

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.)

Footnotes

*

Present address: Centre de Recherehes Pétrographiques et Géochimiques, BP 20, 54501 Vandæuvre1ès-Nancy.

References

Beckinsale, R. D., Suensilpong, S., Nakapadungrat, S., and Walsh, J. N. (1979) J. Geol. Soc. London, 136, 529-40.CrossRefGoogle Scholar
Burnham, C. W. (1979) In The Evolution of Igneous Rocks, 50th Anniversary Perspectives (Yoder, H. S., ed.), Princeton University Press.Google Scholar
Dowty, E. (1980) In Physics of Magmatic Processes (Hargraves, R. B., ed.), Princeton University Press.Google Scholar
Dunham, A. C., and Wilkinson, F. C. F. (1978) X-ray Spectrom. 2, 50-6.CrossRefGoogle Scholar
Foit, F. F., and Rosenberg, P. E. (1977) Contrib. Mineral. Petrol. 62, 109-27.CrossRefGoogle Scholar
Foit, F. F., and Rosenberg, P. E. (1979) Am. Mineral. 64, 788-98.Google Scholar
Garson, M. S., Young, B., Mitchell, A. H. G., and Tait, B. A. R. (1975) Overseas Mere. Inst. Geol. Sci. London, 1.Google Scholar
Hutchison, C. S. (1977) Bull. Geol. Soc. Malaysia, 9, 187-207.CrossRefGoogle Scholar
Jahns, R. H., and Burnham, C. W. (1969) Econ. Geol. 64, 843-64.CrossRefGoogle Scholar
Lister, C. J. (1979) Proc. Ussher Soc. 4, 40218.Google Scholar
Lofgren, G. (1980) In Physics of Magmatic Processes (Hargraves, R. B., ed.), Princeton University Press.Google Scholar
McCurry, P. (1971) Am. Mineral. 36, 1078-89.Google Scholar
Manning, D. A. C., Hamilton, D. L., Henderson, C. M. B., and Dempsey, M. J. (1980) Contrib. Mineral. Petrol. 75, 257-62.CrossRefGoogle Scholar
Neiva, A. M. R. (1974) Geochim. Cosmochim. Acta, 38, 1307-17.CrossRefGoogle Scholar
Nemec, D. (1973) Neues Jahrb. Mineral., Monatsh., 58-63.Google Scholar
Power, G. M. (1968) Mineral, Mao. 36, 1078-89.Google Scholar
Putthapiban, P., and Suensilpong, S. (1978) J. Geol. Soc. Thailand, 3, M1, 1-22.Google Scholar
Rosenberg, P. E., and Foit, F. F. (1979) Am. Mineral. 64, 180-6.Google Scholar