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The neoformation of clay minerals in brackish and marine environments

Published online by Cambridge University Press:  09 July 2018

C. V. Jeans
C. V. Jeans*
Affiliation:
Sedgwick Museum, Cambridge
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Abstract

It is suggested (1) that large amounts of Al, Fe and Si carried in solution by fresh water are chemically precipitated as hydroxide gels in the brackish water environment of estuaries and deltas, and (2) that these gels are subsequently deposited in both the brackish water environment and in the neighbouring seas, where they become parental material for the neoformation of clay minerals, and various other silicate and iron minerals. The types of neoformed minerals will depend upon both the composition of the parental gels and the physico-chemical milieu of their crystallization. Evidence is discussed supporting this hypothesis from the following sources (1) the concentrations of Al, Fe and Si dissolved in fresh water and in sea-water, (2) experimental work on the crystallization of alumino-siliceous gels, and (3) a study of the precipitation of Si from the waters of the Mississippi River delta.

Because of the unusual sediment pattern of present times, this source of neoformed clay minerals and other minerals contributes only a small proportion of the sediments of the brackish parts of estuaries, deltas and the adjacent seas, which are dominated by fine-grained continental detritus. In earlier geological eras, when the world's river systems carried only relatively minor amounts of fine-grained continental detritus, this source of neoformed minerals is likely to have contributed a considerable proportion of the fine-grained sediments of these areas of sedimentation. Three possible examples are discussed.

Type
Research Article
Information
Clay Minerals , Volume 9 , Issue 2 , December 1971 , pp. 209 - 217
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1971

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References

Barth, T.F.W. (1952) Theoretical Petrology, pp. 30-4. J. Wiley & Sons Inc., New York.Google Scholar
Bien, G.S., Contois, D.E. & Thomas, W.H. (1959) The removal of soluble silica from fresh water entering the sea in Silica in Sediments, special publication No. 7 of the Society of Economic Palaeontologists and Mineralogists, 20.Google Scholar
Broecker, W. (1963) The Sea. Vol. 2, (M. N. Hill, editor), Chap. 4, p. 103. J. Wiley & Sons Inc., New York.Google Scholar
Caillère, S., Hénin, S. & Estéoule, J. (1963) Clay Miner. Bull, 5, 272.Google Scholar
Clarke, F.W. (1924) Bull. U.S. geol. Surv., 770.Google Scholar
Cooper, L.H.N. (1938) Proc. R. Soc. Series B, 124, 299.Google Scholar
Goldberg, E.D. (1963) The Sea. Vol. 2, (M. N. Hill, editor), Chap. 1, p. 3. J. Wiley & Sons Inc., New York.Google Scholar
Holmes, A. (1965) Principles of Physical Geology, pp. 515-7. T. Nelson & Sons Limited, London.Google Scholar
Jeans, C.V. (1968) Clay Miner., 7, 311.Google Scholar
Krauskopf, K. (1967) Introduction to Geochemistry, pp. 151-3. McGraw-Hill, New York.Google Scholar
Livingstone, D.A. (1963) Prof. Pap. U.S. geol. Surv., 440-G.Google Scholar
Millot, G. (1964) Geologie des Argiles, pp. 396-9. Masson & Cie, Paris.Google Scholar
Pryor, W.A. (1960) Bull. Am. Ass. Petrol. Geol., 44(2), 1473.Google Scholar
Pryor, W.A. & Glass, H.D. (1961) J. sedim. Petrol., 31, 38.Google Scholar
Waagé, K.M. (1961) Bull. U.S. geol. Surv., 1102.Google Scholar