Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-22T22:17:58.457Z Has data issue: false hasContentIssue false
  • English
  • Français

An Occurrence of Authigenic Nacrite

Published online by Cambridge University Press:  02 April 2024

D. Bühmann
D. Bühmann*
Affiliation:
Department of Geology and Mineralogy, University of Natal, Pietermaritzburg, Republic of South Africa
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Euhedral, pseudohexagonal nacrite was discovered as a thin layer coating a carbonaceous shale in the Sherwood Tunnel in Durban, Republic of South Africa. The nacrite apparently formed authigenically within a few weeks at ambient temperature by precipitation from pore solutions, probably as a result of evaporation. This observation suggests that nacrite can no longer be considered to indicate a high-temperature genetic environment. Precipitation from saturated pore solution may have been the mechanism of formation for this kaolin-mineral polymorph.

Keywords

AuthigenesisKaolin-group mineralNacritePore solutionShale
Type
Research Article
Information
Clays and Clay Minerals , Volume 36 , Issue 2 , April 1988 , pp. 137 - 140
Copyright
Copyright © 1988, The Clay Minerals Society

References

Bailey, S. W., Brindley, G. W. and Brown, G., 1980 Structures of layer silicates Crystal Structures of Clay Minerals and their X-ray Identification London Mineralogical Society 1 – 123.Google Scholar
Eberl, D. and Hower, J., 1975 Kaolinite synthesis: The role of the Si/Al and the alkali/H+ ratio in hydrothermal systems rlays & Clay Minerals 23 301 – 309.CrossRefGoogle Scholar
Firman, R. J., 1953 On the occurrence of nacrite at Shap, Westmorland Mineral. Mag. 30 199 – 200.Google Scholar
Garrels, R. M. and Christ, C. L., 1965 Solutions, Minerals, and Equilibria New York Harper.Google Scholar
Giese, R. F. Jr., 1973 Interlayer bonding in kaolinite Clays & Clay Minerals 21 145 – 149.CrossRefGoogle Scholar
Gorlich, E., 1957 Origin of clay minerals Arch. Mineral. (Poland) 409 – 426.Google Scholar
Grim, R. E., 1968 Clay Mineralogy 2nd New York McGraw-Hill.Google Scholar
Hanson, R. F., Zamara, R. and Keller, W. D., 1981 Nacrite, dickite, and kaolinite in one deposit in Nayarit, Mexico Clays & Clay Minerals 29 451 – 453.CrossRefGoogle Scholar
Huang, W. H. and Keller, W. D., 1973 New stability diagrams of some phyllosilicates in the SiO2-Al2O3-K2O-H2O system Clays & Clay Minerals 21 331 – 336.CrossRefGoogle Scholar
Keller, W. D., 1976 Scan electron micrographs of kaolins collected from diverse environments of origin—I Clays & Clay Minerals 24 107 – 113.CrossRefGoogle Scholar
La Iglesia, A. and Van Oosterwyck, M. C., 1978 Kaolinite synthesis. I. Crystallization conditions at low temperatures and calculation of thermodynamic equilibria. Application to laboratory and field observations Clays & Clay Minerals 26 397 – 408.CrossRefGoogle Scholar
Lippmann, F., van Olphen, H. and Veniale, F., 1982 The thermodynamic status of clay minerals Proc. 7th Int. Clay Conf., Bologna, Pavia, 1981 Amsterdam Elsevier 475 – 485.Google Scholar
Millot, G., 1970 Geology of Clays New York Springer-Verlag.CrossRefGoogle Scholar
Newham, R. E., 1963 A refinement of the dickite structure and some remarks on polymorphism in kaolin minerals Mineral. Mag. 32 683 – 704.Google Scholar
Parham, W. E., 1969 Formation of halloysite from feldspar: Low temperature artificial weathering versus natural weathering Clays & Clay Minerals 17 13 – 22.CrossRefGoogle Scholar
Ross, C. S. and Kerr, P. F., 1931 The kaolin minerals U.S. Geol. Surv. Prof. Pap. 165 151 – 180.Google Scholar
Van Oosterwyck-Gastuche, M. C. and La Iglesia, A., 1978 Kaolinite synthesis. II. A review and discussion of the factors influencing the rate process Clays & Clay Minerals 26 409 – 417.CrossRefGoogle Scholar
von Brunn, V. and Gravenor, C. P., 1984 A model for late Dwyka glaciomarine sedimentation in the Eastern Karoo Basin Trans. Geol. Soc. S. Afr. 86 199 – 209.Google Scholar