Hostname: page-component-84b7d79bbc-g7rbq Total loading time: 0 Render date: 2024-07-25T07:40:31.198Z Has data issue: false hasContentIssue false
  • English
  • Français

Scan Electron Micrographs of Kaolins Collected from Diverse Environments of Origin—IV. Georgia Kaolin and Kaolinizing Source Rocks

Published online by Cambridge University Press:  01 July 2024

W. D. Keller
W. D. Keller*
Affiliation:
Geology Department, University of Missouri-Columbia, Columbia, MO 65201, U.S.A.
Get access Rights & Permissions [Opens in a new window]

Abstract

Scan electron micrographs (SEMs), are shown of three representative types of Georgia kaolin: ‘soft’, Cretaceous-age clay; ‘hard’, fine-grained clay; and ‘flint kaolin’.

Sparta Granite and a thick deposit of its overlying saprolite are taken to serve as examples of probable source rock for Georgia kaolin. SEMs are presented to show sequential argillation of this fresh granite through a transition zone to the saprolite. The saprolite contains abundant books of kaolinite similar to those occurring in Cretaceous kaolin, accompanied by some elongates, whereas in the transition zone elongates are predominant. A morphologic type of fibrous, elongate 1:1 clay mineral, hitherto not illustrated, is shown from kaolinizing Sparta Granite, and from Pre-Cambrian saprolitic gneiss 25 km south of Athens, GA.

Whereas kaolin elongates originated in contact with feldspar in the Sparta transition zone, well-formed books of kaolinite are shown to have been formed in contact with feldspar in the saprolite from a Missouri granite. The arkose above the granite in the Missouri occurrence has altered to loosely packed books of kaolinite. The interpretation is made that book-type kaolinite, where it occurs in large deposits of saprolite or kaolin, was formed under geochemical conditions of relative chemical stability between kaolinite and feldspar, as might prevail in a geological ‘weathering crust’. It is interpreted that elongate kaolin morphology may be formed under conditions of limited or lesser geochemical stability.

SEMs show that the established book-morphology of Sparta saprolite is disarranged during secondary Holocene surface weathering and pedogenic processing.

SEMs show that books of kaolinite, although individually fragile, may be protected from destruction or delamination during artificial blunging and transport when moved within naturally coalesced pellets. Possibly original books of weathered kaolinite might similarly survive natural stream transport during sedimentational processes.

Some ‘flint kaolin’ contains molds of sponge spicules coated with low-cristobalite.

Type
Research Article
Information
Clays and Clay Minerals , Volume 25 , Issue 5 , October 1977 , pp. 311 - 345
Copyright
Copyright © Clay Minerals Society 1977

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

API, Amer. Petrol. Inst., Project 49 (1949) Reference Clay Minerals, Prelim. Rep., 1–8, Paul F. Kerr and others, Columbia University.Google Scholar
Austin, R. S. (1976) The origin of Georgia's kaolin deposits: preprint: 1976 Forum Geology of Industrial Minerals, Atlanta, GA; Geologic and Water Division, 17 pp. Georgia Dept of Natural Resources.Google Scholar
Baumann, D. and Keller, W. D. (1975) Bulk densities of selected dried natural and fired kaolin clays: Clays and Clay Minerals 23, 424–427.CrossRefGoogle Scholar
Blaxland, A. B. (1974) Geochemistry and geochronology of chemical weathering, Butler Hill Granite, Missouri: Geochim. Cosmochim. Acta 38, 843–852.CrossRefGoogle Scholar
Grim, R. E. and Wahl, F. M. (1968) Kaolin deposits of Georgia and South Carolina, U.S.A.: XXIII Int. Geol. Cong., Vol. 14, 9021.Google Scholar
Hinckley, D. N. (1961) Mineralogical and chemical variations in the Coastal Plain of Georgia and South Carolina: Ph.D. Thesis, Penna State University, 194 pp.Google Scholar
Jonas, E. C. (1964) Petrology of the Dry Branch, Georgia, kaolin deposits: Proc. 12th Natl Clay Conf., Clays and Clay Minerals, 199–205.Google Scholar
Keller, E. D. (1963) Hydrothermal kaolinization (endellitization) of volcanic glassy rock: 10th Natl Conf. Clays and Clay Minerals, pp. 333–343. Pergamon Press, Oxford.Google Scholar
Keller, W. D. (1976) Scan electron micrographs of kaolins collected from diverse origins, Parts I, II, III, V: Clays and Clay Minerals 24, 107–113, 114–117, 262–264; 25.CrossRefGoogle Scholar
Keller, W. D. and Hanson, R. F. (1975) Dissimilar fabrics by scan electron microscopy of sedimentary versus hydrothermal kaolins in Mexico: Clays and Clay Minerals 23, 201–204.CrossRefGoogle Scholar
Kesler, T. L. (1963) Environment and origin of the Cretaceous kaolin deposits of Georgia and South Carolina: Georgia Mineral Newsletter 18(1–2), 3–11.Google Scholar
Kesler, T. L. (1956) Environment and origin of the Cretaceous kaolin deposits of Georgia and South Carolina: Econ. Geol. 51, 541–554.CrossRefGoogle Scholar
Klinefelter, T. A., O'Meara, R. G., Truesdell, G. C. and Gottlieb, S. (1943) Hard and soft kaolins of Georgia: U.S. Bur. Mines, Rep. Invest. 3682, 20 pp.Google Scholar
Meunier, A. and Velde, B. (1976) Mineral reactions at grain contacts in early stages of weathering: Clay Minerals 11, 235–240.CrossRefGoogle Scholar
Murata, K. J. and Larson, R. R. (1975) Diagenesis of Miocene siliceous shales, Temblar Range, California: J. Res. U.S. Geol. Survey 3, 553–566.Google Scholar
Murray, H. H. (1976) The Georgia sedimentary kaolins: 7th Symp. Genesis of Kaolin, Int. Geol. Correlation Program, Committee on Correlation of Age and Genesis of Kaolin, Tokyo, pp. 114–125.Google Scholar
Parham, W. E. (1969) Formation of halloysite from feldspar: low temperature, artificial weathering versus natural weathering: Clays and Clay Minerals 17, 13–22.CrossRefGoogle Scholar
Patterson, S. H. and Buie, B. F. (1974) Field conference on kaolin and fuller's earth, Nov. 14–16, 1974: Guidebook 14, Geo. Geol. Surv. and Soc. Econ. Geol., 53 pp.Google Scholar
Patterson, S. H. and Murray, H. (1975) Clays: Industrial Minerals and Rocks (Nonmetallics other than Fuels), 4th edition, pp. 519–585. AIMMPE, New York.Google Scholar
Reesman, A. L. (1966) A study of clay mineral dissolution: Ph.D. dissertation, University of Mo.–Columbia.Google Scholar
Reesman, A. L. and Keller, W. D. (1968) Aqueous solubility studies of high-alumina and clay minerals: Am. Miner. 53, 929–942.Google Scholar
Smith, R. W. (1929) Sedimentary kaolins of the Coastal Plain of Georgia: Georgia Geol. Surv. Bull. 44, 474 pp.Google Scholar
Wada, K., Henmi, T., Yoshinaga, N. and Patterson, S. H. (1972) Imogolite and allophane formed in saprolite on Maui, Hawaii: Clays and Clay Minerals 20, 375–380.CrossRefGoogle Scholar