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Asymmetric Zonation of a Thick Ordovician K-Bentonite Bed at Kinnekulle, Sweden

Published online by Cambridge University Press:  02 April 2024

Ann Marie Brusewitz
Ann Marie Brusewitz*
Affiliation:
Geological Survey of Sweden, Box 670, S-75128 Uppsala, Sweden
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Abstract

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The clay fraction of a ∼2-m-thick K-bentonite at Kinnekulle in southwestern Sweden has been studied by X-ray powder diffraction, chemical analyses, and cation-exchange capacity determinations. Previous investigations of the upper half of this bed (B-bed) have shown the clay mineral to be illite/smectite (I/S), containing about 50% illite layers at the center of the bed and 65% illite layers at the upper contact. New data on six samples from the lower part of the bed show no zonation, the I/S containing about 50% illite layers in all samples. The bentonite occurs in limestones and shales overlying a 40-m-thick limestone bed and is overlain by limestones, marls, and shales (∼90 m), which in turn are overlain by a 40-m-thick diabase. The limestones are silicified in contact with the bentonite, particularly beneath the B-bed. The increased K content towards the upper contact may therefore have resulted from diffusion of K-bearing solutions from overlying shales, a process that was impeded in the lower part of the bed, probably by the silicification.

Keywords

BentoniteDiagenesisIllite/smectitePotassiumShaleX-ray powder diffraction
Type
Research Article
Information
Clays and Clay Minerals , Volume 36 , Issue 4 , August 1988 , pp. 349 - 353
Copyright
Copyright © 1988, The Clay Minerals Society

References

Altaner, S. P., Hower, J., Whitney, G. and Aronson, J. L., 1984 Model for K-bentonite formation: Evidence from zoned K-bentonites in the disturbed belt, Montana Geology 12 412 – 415.2.0.CO;2>CrossRefGoogle Scholar
Bramlette, M. N. (1946) The Monterey Formation of California and the origin of its siliceous rocks: U.S. Geol. Surv. Prof. Pap. 212, 57 pp.Google Scholar
Brusewitz, A. M., 1982 A filtering device for oriented XRD mounts Clay Miner. 17 263 – 264.CrossRefGoogle Scholar
Brusewitz, A. M., 1984 Preliminary report on potassium bentonites in Sweden. A study of illite-smectite minerals Smectite Alteration, D. M. Anderson, compiler, Swedish Nuclear Fuel and Waste Management Company, Tech. Rept. 84 11 105 – 121.Google Scholar
Brusewitz, A. M., 1986 Chemical and physical properties of Paleozoic potassium bentonites from Kinnekulle, Sweden Clays & Clay Minerals 34 442 – 454.CrossRefGoogle Scholar
Byström, A. M. (1956) Mineralogy of the Ordovician bentonite beds at Kinnekulle, Sweden: Sver. Geol. Unders. serie C, No. 540, 62 pp.Google Scholar
Byström-Asklund, A. M., Baadsgaard, A. and Folinsbee, R. E., 1961 K/Ar age of biotite, sanidine and illite from Middle Ordovician bentonites at Kinnekulle, Sweden Geol. Foren. Stockholm Förh. 83 92 – 96.CrossRefGoogle Scholar
Drever, J.J., 1973 The preparation of oriented clay mineral specimens for X-ray diffraction analysis by a filter membrane peel technique Amer. Mineral. 58 553 – 554.Google Scholar
Hoffman, J., 1976 Regional metamorphism and K/Ar dating of clay minerals in Cretaceous sediments of the disturbed belt of Montana Ph.D. thesis Cleveland, Ohio Case Western Reserve University.Google Scholar
Inoue, A., Kohyama, N., Kitagawa, R. and Watanabe, T., 1987 Chemical and morphological evidence for the conversion of smectite to illite Clays & Clay Minerals 35 111 – 120.CrossRefGoogle Scholar
Jaanusson, V. (1964) The Viruan (Middle Ordovician) of Kinnekulle and northern Billingen, Västergötland: Bull. Geol. Inst. Univ. Uppsala 43, 73 pp.Google Scholar
Johansson, S., Sundius, N. and Westergård, A. H. (1943) Description of the mapsheet “Lidköping”: Sver. Geol. Unders. Ser. Aa No. 182, 197 pp. (in Swedish).Google Scholar
Kunk, M. D., Sutter, J. and Bergström, S. H., 1984 40Ar-39 Ar age spectrum dating of biotite and sanidine from Middle Ordovician bentonites of Sweden: A comparison with results from eastern North America Abstracts with Prog., Geol. Soc. Amer. 16 566.Google Scholar
Mudge, M. R. (1972) Pre-Quarternary rocks in the Sun River Canyon area, northwestern Montana: U.S. Geol. Sun. Prof. Pap. 663–A, 142 pp.Google Scholar
Reynolds, R. C., Brindley, G. W. and Brown, G., 1980 Interstratified minerals Crystal Structures of Clay Minerals and their X-ray Identification London Mineralogical Society 255.Google Scholar
Shapiro, L., 1960 A spectrophotometry: method for the determination of FeO in rocks U.S. Geol. Surv. Research—Short Papers in the Geological Sciences: U.S. Geol. Surv. Prof. Pap. 400–B B496 – B497.Google Scholar
Shapiro, L. (1975) Rapid analysis of silicate, carbonate, and phosphate rocks: Revised edition: U.S. Geol. Surv. Bull. 1401, 76 pp.Google Scholar
Skoglund, R. (1963) Uppermost Viruan and lower Harjuan (Ordovician) stratigraphy of Västergötland, and lower Harjuan Graptolite Faunas of central Sweden: Bull. Geol. Inst. Univ. Uppsala 42, 55 pp.Google Scholar
Srodon, J., 1980 Precise identification of illite/smectite interstratification by X-ray powder diffraction Clays & Clay Minerals 28 401 – 411.CrossRefGoogle Scholar
Thorslund, P., Waern, B., Thorslund, P. and Henningsmoen, G., 1948 The Chasmops series of the Kullatorp core Deep Boring Through Ordovician and Silurian Strata at Kinnekulle, Vestergötland 343 – 373.Google Scholar
Velde, B. and Brusewitz, A. M., 1982 Metasomatic and non-metasomatic low grade metamorphism of Ordovician meta-bentonites in Sweden Geochim. Cosmochim. Acta 46 447 – 452.CrossRefGoogle Scholar
Williams, I. S., Tetley, N. W., Compston, W. and McDougall, I., 1982 A comparison of K-Ar and Rb-Sr ages of rapidly cooled igneous rocks: Two points in the Palaeozoic time scale re-evaluated J. Geol. Soc. London 139 557 – 568.CrossRefGoogle Scholar