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Chemistry of dark zinnwaldite from bom futuro tin mine, Rondônia, Brazil

Published online by Cambridge University Press:  05 July 2018

G. R. Lowell  and
M. Ahl
G. R. Lowell*
Affiliation:
Department of Geosciences, Southeast Missouri State University, Cape Girardeau, Missouri, USA
M. Ahl
Affiliation:
Department of Geology and Geochemistry, Stockholm University, S-106 91 Stockholm, Sweden
*
*E-mail: [email protected]
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Abstract

Physical and chemical properties of lustrous black mica from greisen veins at the Bom Futuro tin mine indicate that it is a relatively Fe-F-rich, Li-poor zinnwaldite with a composition near the midpoint of the polylithionite-siderophyllite join. On the basis of 22 oxygens, the mica contains 1.28–1.73 atoms of Li with an average octahedral occupancy of 5.61 and a filled interlayer site. Compositional variation reflects the net effects of alteration, coupled tetrahedral-octahedral substitutions, and petrogenetic factors related to vein fluid chemistry. Geological constraints and compositional data suggest the Bom Futuro zinnwaldite crystallized at T ≈ 500°, P ≈ 1–500 bar, and fO2 ≈ 10−23. High Mn-Zn concentrations in the Bom Futuro mica appear to be a feature of Fe-Li micas from evolved anorogenic granitic systems not shared by orogenic counterparts.

Keywords

micazinnwalditegreisenSn mineralizationBom Futuro mineBrazil
Type
Research Article
Information
Mineralogical Magazine , Volume 64 , Issue 4 , August 2000 , pp. 699 - 709
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

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References

Bailey, J.C. (1977) Fluorine in granitic rocks and melts: a review. Chem. Geol., 19, 1–42.CrossRefGoogle Scholar
Bailey, S.W. (1984) X-ray powder patterns of micas. Pp. 580–1 in: Micas (Bailey, S.W., editor). Reviews in Mineralogy 13, Mineralogical Society of America, Washington D.C. CrossRefGoogle Scholar
Bettencourt, J.S. and Pereira, N.M. (1995) The Rondônia tin province (a brief historical development). Symposium on Rapakivi Granites and Related Rocks (Belém, Brazil), Excursion Guide, 1–4.Google Scholar
Bettencourt, J.S., Leite, W.B., Payolla, B.L., Scandolara, J.E., Muzzolon, R. and Vian, J.A.J. (1997) The rapakivi granites of the Rondônia tin province, northern Brazil. International Symposium on Granites and Associated Mineralizations (Salvador, Brazil), Excursion Guide, 1–31.Google Scholar
Černý, P. and Burt, D.M. (1984) Paragenesis, crystallo-chemical characteristics, and geochemical evolution of micas in pegmatites. Pp. 257–91 in: Micas (Bailey, S.W., editor). Reviews in Mineralogy 13, Mineralogical Society of America, Washington D.C. CrossRefGoogle Scholar
Chaudhry, M.N. and Howie, R.A. (1973) Lithium-aluminium micas from the Meldon aplite, Devonshire, England. Mineral. Mag., 39, 289–96.CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1966) An Introduction to the Rock-Forming Minerals. Longman, London.Google Scholar
Foster, M.D. (1960) Interpretation of the composition of lithium micas. U.S. Geol. Surv. Prof. Paper, 354-E, 115–47.Google Scholar
Griffin, D.T. (1992) Silicate Crystal Chemistry. Oxford University Press, Oxford, UK.Google Scholar
Harada, K., Honda, M., Nagashima, K. and Kanisawa, S. (1976) Masutomilite, manganese analogue of zinnwaldite, with special reference to masutomilite-lepidolite- zinnwaldite series. Mineral. J. (Japan), 8, 95–109.CrossRefGoogle Scholar
Hazen, R.M. and Wones, D.R. (1972) The effect of cation substitutions on the physical properties of trioctahedral micas. Amer. Mineral., 57, 103–29.Google Scholar
Henderson, C.M.B., Martin, J.S. and Mason, R.A. (1989) Compositional relations in Li-micas from S.W. England and France: an ion- and electron- microprobe study. Mineral. Mag., 53, 427–49.CrossRefGoogle Scholar
Levillain, C. (1980) Etude statistique des variations de la teneur en OH et F dans les micas. Tschmermaks Mineral. Petrogr. Mitt., 27, 209–23.CrossRefGoogle Scholar
Lowell, G.R. and Ahl, M. (1997) Chemical and physical properties of zinnwaldite from Bom Futuro tin mine, Rondônia, north Brazil. International Symposium on Granites and Associated Mineralizations (Salvador, Brazil), Extended Abstracts and Program, 62–3.Google Scholar
Lowell, G.R. and Tobey, E.F. (1979) Composition of an unusual zinnwaldite from southeastern Missouri. Mineral. J.(Japan), 9, 445–59.CrossRefGoogle Scholar
Manning, D.A.C. (1981) The effect of fluorine on the liquidus phase relationships in the system Qz-Ab-Or with excess water at 1 kbar. Contrib. Mineral. Petrol., 76, 257–62.CrossRefGoogle Scholar
Moura, M.A. and Botelho, N.F. (1994) Estudo de micas litiníferas e sua importância para a caracterizaçao das rochas da zona greisenizada principal do maciço estanífero Mangabeira, GO. Bol. Geociências Centro-Oeste, 17, 39–48.Google Scholar
Rieder, M. (1970 a) Chemical composition and physical properties of lithium-iron micas from the Krušné hory Mts. (Erzgebirge), Part A: chemical composition. Contrib. Mineral. Petrol., 27, 131–58.CrossRefGoogle Scholar
Rieder, M. (1970 b) Lithium-iron micas from the Krušné hory Mountains (Erzgebirge): twins, epitactic overgrowths and polytypes. Zeits. Kristallogr., 132, 161–84.CrossRefGoogle Scholar
Rieder, M. (1971) Stability and physical properties of synthetic lithium-iron micas. Amer. Mineral., 56, 256–80.Google Scholar
Rieder, M., Pichova, A., Fassova, M., Fediukova, E. and Černý, P. (1971) Chemical composition and physical properties of lithium-iron micas from the Krušné hory (Erzgebirge), Czechoslovakia and Germany, Part B: cell parameters and optical data. Mineral. Mag., 38, 190–6.CrossRefGoogle Scholar
Rieder, M., Haapala, I. and Pavondra, P. (1996) Mineralogy of dark mica from the Wiborg rapakivi batholith, southeastern Finland. Eur. J. Mineral., 8, 593–605.CrossRefGoogle Scholar
Rosenberg, P.E. and Foit, F.F. (1977) Fe2+-F avoidance in silicates. Geochim. Cosmochim. Acta, 41, 345–6.CrossRefGoogle Scholar
Silva, L.F.S. da, Costi, H.T. and Teixeira, J.T. (1995) Faciologic mapping and preliminary petrography of Palanqueta albite granite–Bom Futuro, Rondônia State (Brazil). Symposium on Rapakivi Granites and Related Rocks (Belém, Brazil), Abstracts Volume, 73–4.Google Scholar
Stone, M., Exley, C.S. and George, M.C. (1988) Compositions of trioctahedral micas in the Cornubian batholith. Mineral. Mag., 52, 175–92.CrossRefGoogle Scholar
Tindle, A.G. and Webb, P.C.(1990) Estimation of lithium contents in trioctahedral micas using microprobe data: application to micas from granitic rocks. Eur. J. Mineral., 2, 595–610.CrossRefGoogle Scholar
Tischendorf, G., Gottesmann, B., Förster, H.-J. and Trumbull, R.B. (1997) On Li-bearing micas: estimating Li from electron microprobe analyses and an improved diagram for graphical representation. Mineral. Mag., 61, 809–34.CrossRefGoogle Scholar
Ukai, Y., Nishimura, S. and Hashimoto, Y. (1956) Chemical studies of lithium micas from the pegmatite of Minagi, Okayama Prefecture. Mineral. J. (Japan), 2, 27–38.CrossRefGoogle Scholar
Villanova, M.T. and Franke, N.D. (1995) Serra do Bom Futuro–Rondônia: a volcanic-breccia pipe-hosted tin mineralization. Symposium on Rapakivi Granites and Related Rocks (Belém, Brazil), Abstracts Volume, 83–4.Google Scholar
Whalen, J.B., Currie, K.L. and Chappell, B.W. (1987) A-type granites: geochemical characteristics, discrimination and petrogenesis. Contrib. Mineral. Petrol., 95, 407–19.CrossRefGoogle Scholar