Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-24T01:26:19.308Z Has data issue: false hasContentIssue false
  • English
  • Français

Zn-rich staurolite from the Uvete area, central Kenya

Published online by Cambridge University Press:  05 July 2018

Akira Miyake
Akira Miyake*
Affiliation:
Department of Earth Sciences, Faculty of Science, Nagoya University, Chikusa 464, Nagoya, Japan
Get access Rights & Permissions [Opens in a new window]

Abstract

Zn-rich staurolite occurs in a pelitic gneiss from the Uvete area, central Kenya. The rock was metamorphosed to staurolite-kyanite grade during the Mozambique metamorphism. Microprobe analyses of the staurolite gave the following values (in wt. %): SiO2 26.2–27.3, Al2O3 52.4–53.5, FeO 8.3–9.2, MgO 2.2–2.6, and ZnO 6.0–7.5. Cell dimensions are a = 7.874(± 0.003), b = 16.620(±0.006), c = 5.656(±0.002) Å and β = 90.00 (± 0.002)°. Optical properties are 2Vz = 82–85°, α = 1.742 (±0.002), β = 1.747(±0.002) and γ = 1.753(±0.002). The optical dispersion is moderate and r > v. Density is 3.83(±0.01) g/cm3. Infra-red absorption spectra were also recorded. The cation correlation suggests that the principal substitutions in the staurolite are Zn ⇆ Fe in the tetrahedral sites in the hydroxide sheet and Al ⇆ Mg in the octahedral sites.

Keywords

staurolitegneissUveteKenya
Type
Research Article
Information
Mineralogical Magazine , Volume 49 , Issue 353 , September 1985 , pp. 573 - 578
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1985

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

Ashworth, J. R. (1975) Staurolite at anomalously high grade. Contrib. Mineral. Petrol. 53, 281-91.CrossRefGoogle Scholar
Bence, A. E., and Albee, A. L. (1968) Empirical correction factors for the electron microanalysis of silicates and oxides. J. Geol. 76, 382–403.CrossRefGoogle Scholar
Borg, I. Y., and Smith, D. K. (1969) Calculated X-ray powder patterns for silicate minerals. Geol. Soc. Am. Mem. 122.CrossRefGoogle Scholar
Chinner, G. A. (1958) The metamorphic history of the Glen Clova District, Angus. Ph.D. thesis, Univ. of Cambridge.Google Scholar
Gibson, G. M. (1978) Staurolite in amphibolite and hornblendite sheets from the Upper Seaforth River, central Fiordland, New Zealand. Mineral. Mag. 42, 153-4.CrossRefGoogle Scholar
Griffen, D. T. (1981) Synthetic Fe/Zn staurolites and the ionic radius of IVZn2+ . Am. Mineral. 66, 932-7.Google Scholar
Griffen, D. T. and Ribbe, P. H. (1973) The crystal chemistry of staurolite. Am. J. Sci. 273-A, 479-95.Google Scholar
Griffen, D. T., Gosney, T. C., and Phillips, W. R. (1982) The chemical formula of natural staurolite. Am. Mineral. 67, 292-7.Google Scholar
Guidotti, C. V. (1970) The mineralogy and petrology of the transition from the lower to upper sillimanite zone in the Oquossoc area, Maine. J. Petrol. 11, 277–336.CrossRefGoogle Scholar
Hietanen, A. M. (1969) Distribution of Fe and Mg between garnet, staurolite, and biotite in aluminum-rich schist in various metamorphic zones north of the Idaho batholith. Am. J. Sci. 267, 422-56.CrossRefGoogle Scholar
Hiroi, Y. (1983) Progressive metamorphism of the Unazuki pelitic schists in the Hida Terrane, central Japan. Contrib. Mineral. Petrol. 82, 334-50.CrossRefGoogle Scholar
Hollister, L. S. (1970) Origin, mechanism, and consequences of compositional sector-zoning in staurolite. Am. Mineral. 55, 742-66.Google Scholar
Hollister, L. S. and Bence, A. E. (1967) Staurolite: Sectorial compositional variations. Science, 158, 1053-6.CrossRefGoogle Scholar
Inoue, H., and Suwa, K. (1979) Petrographical note on staurolite-kyanite-almandine pelitic gneiss occurring at the western foot of the Mbooni Hills, Machakos area, Kenya—with special reference to the ZnO content in staurolite. 4th Prelim. Rept. Afr. Studies, Nagoya Univ. 97-111.Google Scholar
Juurinen, A. (1956) Composition and properties of staurolite. Ann. Acad. Sci. Fenn. Ser. A, III Geol. 47, 1-53.Google Scholar
Keller, W. D., Spotts, J. H., and Biggs, D. L. (1952) Infrared spectra of some rock-forming minerals. Am. J. Sci. 250, 453-71.CrossRefGoogle Scholar
Kochetkova, K. V., Kovalev, K. R., Borisenko, A. S. and Pavlyuchenko, V. S. (1981) Composition and properties of zinc-bearing staurolites from the Kholodinsky deposit (western Lake Baikal region). Zap. Vses. Min. obsh. 110, 310-18 (in Russian).Google Scholar
Miyake, A. (1983) Petrological study of pelitic and psammitic gneisses in the Uvete area, Kenya. 8th Prelim. Rept. Afr. Studies, Nagoya Univ. 75-95.Google Scholar
Miyake, A. (1984) Phase equilibria in the hornblende-bearing basic gneisses in the Uvete area, central Kenya. J. Metamorphic Geol. 2, 165-77.CrossRefGoogle Scholar
Miyake, A. and Suwa, K. (1981) Geological structure of the Uvete dome, Kenya. 6th Prelim. Rept. Aft. Studies, Nagoya Univ. 3341.Google Scholar
Naray-Szabo, I. (1929) The structure of staurolite. Z. Kristalloor. 71, 103-16.Google Scholar
Saksena, B. D. (1961) Infra-red absorption studies of some silicate structures. Trans. Faraday Soc. 57, 242-55.CrossRefGoogle Scholar
Smith, J. V. (1968) The crystal structure of staurolite. Am. Mineral. 53, 1139-55.Google Scholar
Snelling, N. J. (1957) A note on the composition of staurolite from the Caenlochan schists. Mineral. Mag. 31, 603-4.Google Scholar
Stoddard, E. F. (1979) Zinc-rich hercynite in high-grade metamorphic rocks: a product of the dehydration of staurolite. Am. Mineral. 64, 736-41.Google Scholar