Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-07-05T21:17:29.398Z Has data issue: false hasContentIssue false
  • English
  • Français

The mineralogy and genesis of uranium in rhyolitic ignimbrites of precambrian age from Duobblon, Sweden

Published online by Cambridge University Press:  05 July 2018

John A. T. Smellie
John A. T. Smellie*
Affiliation:
Geological Survey of Sweden, Box 801, Luleå, Sweden
Get access Rights & Permissions [Opens in a new window]

Abstract

The Duobblon rhyolitic ignimbrites, of middle Precambrian age are 60 m thick. They consist of at least three flows with varying degrees of welding and have undergone devitrification, producing lithophysal and spherulitic textures. They are overlain by thick fluviatile red-bed-type conglomerates and sandstones, which in turn are capped by terrestrial acid volcanics.

Uranium enrichments of up to 3000 ppm U occur within two or three peneconcordant tabular horizons which are mostly lithophysae-bearing. Fission-track investigations of the ignimbrites and overlying conglomerates and sandstones, which supplement earlier mineralogical studies, show that U occurs as fine pitchblende disseminations; as complex uranotitanates associated with Fe-Ti-Mn oxides; and as coatings associated with matrix sericite. Small amounts of O are present in such primary accessory minerals as sphene, apatite, and zircon.

It is suggested that oxidizing U-bearing solutions, generated partly during devitrification of the ignimbrites and partly from the overlying volcano-sedimentary pile, produced the U enrichments with later sulphide deposition, along the more permeable lithophysal horizons in the ignimbrites.

Type
Research Article
Information
Mineralogical Magazine , Volume 46 , Issue 339 , June 1982 , pp. 187 - 199
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.)

References

Refrences

Adamek, P., and Wilson, M. R. (1979 Proc. R. Soc. Lond. 291, 355-68.Google Scholar
Anderson, W. B. (1975 Unpubl. MA thesis, University of Texas, Austin.Google Scholar
Einarsson, Ö. (1970 Unpubl. Ph.D. thesis, University of Stockholm.Google Scholar
Einarsson, Ö. (1979 SGU, Ser. C. 748.Google Scholar
Guarascio, M. (1976 Improving the uranium deposits estimations (the Novazza case). In NATO advanced study institute series, ser. C, mathematical and physical sciences. Advanced ffeostatistics in the mining industry, D. Reidel Publ. Co., Dordrecht, Holland. 351-67.CrossRefGoogle Scholar
Haffty, J., and Noble, D. C. (1972 Econ. Geol. 67, 768-75.CrossRefGoogle Scholar
Kleeman, J. D., and Lovering, J. F. (1967 Science, 156, 512-13.CrossRefGoogle Scholar
Lilljequist, R., and Svensson, S-,Å (1974 Geol. För. Stockh. Förh. 96, 221-9.CrossRefGoogle Scholar
Lindroos, H. (1980 Int. Rep. SGU.Google Scholar
Lindroos, H. and Smellie, J. A. T. (1979 Econ. Geol. 74, 1118-30.CrossRefGoogle Scholar
Lipman, P. W. (1965 US Geol. Survey Bull. 1201-D.Google Scholar
Lipman, P. W. Christiansen, R. L., and Van Alstine, R. E. (1969 Am. Mineral. 54, 286-91.Google Scholar
Löfvendahl, R. (1981 SGU, Ser. C. 779.Google Scholar
Noble, D. C., Smith, V. C., and Peck, L. C. (1967 Geochim. Cosmochim. Acta, 31, 215-23.CrossRefGoogle Scholar
Rogers, J. J. W., and Adams, J. S. S. (1969 Uranium. In Wedepohl, K. H., ed. Handbook of geochemistry, 4. New York, Springer-Verlag.Google Scholar
Rosholt, J. N., and Noble, D. C. (1969 Earth. Planet. Sci. Lett. 6, 268-70.CrossRefGoogle Scholar
Rosholt, J. N., and Noble, D. C. Prijana, and Noble, D. S. (1971 Econ. Geol. 66, 1061-9.CrossRefGoogle Scholar
Ross, C. S., and Smith, R. L. (1961 US Geol. Survey Prof. Paper 366. 81 pp.Google Scholar
Scott, R. B. (1971 J. Geol. 79, 100-10.CrossRefGoogle Scholar
Shatkov, G. A., Shatkova, L. N., and Guschin, E. N. (1970 Geochem. Int. 7, 1051-63.Google Scholar
Welin, E. (1980 Geol. För. Stockh. Förh. 101, 309-20.CrossRefGoogle Scholar
Welin, E. Einarsson, Ö., and Nilsson, Ö. (1971 SGU, Ser. C. 666.Google Scholar
Zielinski, R. A. (1978 Geol. Soc. Am. Bull. 89, 409-14.2.0.CO;2>CrossRefGoogle Scholar
Zielinski, R. A. Lipman, P. W., and Millard, H. T., Jr. (1977 Am. Mineral. 62, 426-37.Google Scholar
Zielinski, R. A., Lindsey, D. A., and Rosholt, J. N. (1980 Chem. Geol. 29, 139-62.CrossRefGoogle Scholar