Skip to main content
Log in

Origin and Classification of Coastal Plain Kaolins, Southeastern USA, and the Role of Groundwater and Microbial Action

  • Published:
Clays and Clay Minerals

Abstract

Along the inner Coastal Plain, kaolinite-metahalloysite-rich, neritic muds of Cretaceous-Eocene age have undergone intense postdepositional alteration in the recharge area of the regional groundwater system. Weathering processes have had the following profound effects on the original sediments: 1) strong compositional and textural modification of both clay and non-clay minerals; 2) whitening of the originally darker sediments by partial removal of organic matter, Fe and Mn; and 3) recrystallization of kaolinite and metahalloysite, most conspicuous where there are coarse stacks and vermiforms. Where the combination of initial sediment composition and alteration intensity was most favorable, these changes have produced important deposits of commercial quality, which now sustain the world’s largest kaolin production district. The earliest change was partial sequestration of iron as sulfide and concurrent destruction of some organic matter, mediated by sulfate-reducing bacteria. Subsequent weathering resulted in gradual leaching of alkalies, alkaline earths, iron and silica, and attendant nucleation and growth of minerals compatible with the compositional changes. The existence of several closely spaced erosional unconformities, separated by neritic sediments, is proof that weathering conditions commonly changed at a given site, in response to changes in thickness or lithology of the overlying rocks. Dsyoxic → ← oxic reversals modified both the rate and kind of alteration. (“Dysoxic” refers to molecular oxygen concentration too low to be toxic to anaerobes or cause abiotic oxidation; less extreme than “anoxic”.) Kaolins were produced partly by slower dysoxic weathering in saturated groundwater zones but mainly by more rapid oxic weathering in unsaturated zones, where bauxites also locally formed. Gradual transformation of some sediments to kaolin rarely began and ended in the same epoch. At several places most of the kaolinization (see “Definitions”) took place during Recent time, tens of millions of years after deposition of the sediments. Since the kaolins resulted from postdepositional alteration rather than sedimentary processes, they are better referred to as “Coastal Plain” rather than “sedimentary” kaolins.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Al-Sanabani GAM. 1991. Palynostratigraphic age and origin of the kaolin deposits in the Inner Coastal Plain in East-Central Georgia [PhD dissertation]. Athens, GA: Univ Georgia. 180 p.

    Google Scholar 

  • Austin RS. 1972. The origin of the kaolin and bauxite deposits of Twiggs, Wilkinson, and Washington Counties, Georgia [Ph.D. dissertation]. Athens, GA: Univ Georgia. 185 p.

    Google Scholar 

  • Barker WW. 1985. Bacterial trace fossils in Eocene Kaolin. In: Bailey GW, editor. Proc 43rd Annu Meet Electron Microscopy Soc Am. San Francisco: San Francisco Pr. p 238–39.

  • Barker WW. 1988. An electron microscopic study of extra-lamellar organoclay complexes [Ph.D. dissertation]. Athens, GA: Univ Georgia. 171 p.

    Google Scholar 

  • Barker WW, Hurst VJ. 1992. Bacterial trace fossils in Eocene kaolin of the Huber Formation of Georgia: Phylloderma microsphaeroides, n. ichnogen., n. ichnos. Ichnos 2:55–60.

    Article  Google Scholar 

  • Barker WW, Hurst VJ. 1993. Freeze-etch replication of extracellular bacterial polymers adsorbed onto kaolinite. In: Bailey GW, Rieder CL, editors. Proc 51st Annu Meet Electron Microscopy Soc Am. San Francisco: San Francisco Pr. p 52–53.

  • Barker WW, Rigsby WE, Hurst VJ, Humphreys WJ. 1982. High resolution replication of organoclay surfaces. In: Bailey GW, editor. Proc 40th Annu Meet Electron Microscopy Soc Am; Washington, DC. Baton Rouge, LA: Claitor’s Publishing Div. p 576–77.

  • Bates RL, Jackson JA, editors. Glossary of geology, 3rd ed. Alexandria, VA: Am Geol Inst. 788 p.

  • Berner RA. 1984. Sedimentary pyrite formation: An update. Geochim Cosmochim Acta 48:605–615.

    Article  Google Scholar 

  • Berner BR, Raiswell R. 1983. Burial of organic carbon and pyrite sulfur in sediments over Phanerozoic time: A new theory. Geochim Cosmochim Acta 47:855–862.

    Article  Google Scholar 

  • Blanchard B. 1968. Interpretation of leached outcrops. Nev Bur Mines Bull 66:196 p.

  • Blatt H, Middleton G, Murray R. 1980. Origin of sedimentary rocks, 2nd ed. Englewood Cliffs NJ: Prentice-Hall. 782 p.

    Google Scholar 

  • Bohor BF, Randall EH. 1971. Scanning electron microscopy of clays and clay minerals. Clays Clay Miner 19:49–54.

    Article  Google Scholar 

  • Brown A, Sherriff B. 1996. Geomicrobiology Symposium at Winnipeg ’96: Geol Assoc Canada and Miner Assoc Canada joint meeting. Program and abstracts, p A13.

    Google Scholar 

  • Chapelle FH. 1993. Groundwater microbiology and geochemistry. New York: J Wiley. 424 p.

    Google Scholar 

  • Chapelle FH, Lovley DR. 1990. Rates of microbial metabolism in deep coastal plain aquifers. Appl Environ Microbiol 53:2636–2641.

    Google Scholar 

  • Chapelle FH, Lovley DR. 1992. Competitive exclusion of sulfate reduction by Fe(III)-reducing bacteria: A mechanism for producing discrete zones of high-iron groundwater. Groundwater 30:29–36.

    Article  Google Scholar 

  • Chapelle FH, Morris JT, McMahon PB, Zelibor JS, Jr. 1988. Bacterial metabolism and the δ13C composition of ground water, Floridan aquifer system. SC Geol 16:117–121.

    Article  Google Scholar 

  • Cramer HR. 1974. Isopach and lithofacies analysis of the Cretaceous and Cenozoic rocks of the Coastal Plain of Georgia. Ga Geol Surv Bull 87:21–44.

    Google Scholar 

  • Dodge JJ. 1991. Estuarine transformation of fluvial khandite, coastal Georgia [M.S. thesis]. Athens, GA: Univ Georgia. 91 p.

    Google Scholar 

  • Dombrowski T. 1992. Trace element distribution of the Georgia kaolins and saprolite from crystalline rock in the adjacent Piedmont—Implications for the origin of the kaolin deposits [Ph.D. dissertation]. Bloomington, IN: Indiana Univ. 132 p.

    Google Scholar 

  • Dombrowski T. 1993. Theories of origin for the Georgia kaolins. In: Murray H, Bundy W, Harvey C, editors. Kaolin genesis and utilization. Boulder, CO: Clay Miner Soc. p 75–98.

    Google Scholar 

  • Dombrowski T, Murray HH. 1984. Thorium—A key element in differentiating Cretaceous and Tertiary kaolins in GA and SC. Proc 27th Int Geol Congr 15:305–317.

    Google Scholar 

  • Eagon RG, Howard SC, Westbrook CE. 1987. The effect of high microbial populations on the physical properties of kaolin slurries. Int Biodeterioration 23:61–68.

    Article  Google Scholar 

  • Ehrlich HL. 1981. Geomicrobiology, 2nd ed. New York: Marcel Dekker. 303 p.

    Google Scholar 

  • Ehrlich HL. 1996. Geomicrobiology, 3rd ed. New York: Marcel Dekker. 719 p.

    Google Scholar 

  • Elzea JM, Odom IE, Miles WJ. 1994. Distinguishing well ordered opal-CT and opal-C from high temperature cristobalite by x-ray diffraction. Anal Chim Acta 286:107–116.

    Article  Google Scholar 

  • Evangelou VP. 1995. Pyrite oxidation and its control. New York: CRC Pr. 293 p.

    Google Scholar 

  • Garreis RM, Mackenzie FT. 1971. Evolution of sedimentary rocks. New York: Norton. 397 p.

    Google Scholar 

  • Gould SJ. 1996. Our life on the earth’s surface, based on solar energy and photosynthesis, may be the exception rather than the rule. Nat History 3:21–23, 66–68.

    Google Scholar 

  • Griffin GM. 1962. Regional clay mineral facies—Products of weathering intensity and current distribution in the northern Gulf of Mexico. Geol Soc Am Bull 73:737–768.

    Article  Google Scholar 

  • Guggenheim S, Martin RT. 1995. Definition of clay and clay mineral. Joint report of the AIPEA nomenclature and CMS nomenclature committees. Clays Clay Miner 43:255–256.

    Article  Google Scholar 

  • Hassanipak AA, Eslinger E. 1985. Mineralogy, crystallinity, O18/O16, and D/H of Georgia kaolins. Clays Clay Miner 33:99–105.

    Article  Google Scholar 

  • Hetrick JH, Friddell MS. 1990. A geologic atlas of the Central Georgia kaolin district. Geologic Atlas 6. Atlanta, GA: Georgia Geol Surv.

    Google Scholar 

  • Hurst VJ. 1977. Visual estimation of iron in saprolite. Geol Soc Am Bull 88:174–176.

    Article  Google Scholar 

  • Hurst VJ. 1980. Saprolite mapping. Athens, GA: Univ Georgia Geology Dept. 103 p.

    Google Scholar 

  • Hurst VJ. 1997. Origin of the kaolins and associated bauxites. In: Pickering SM, Jr, Hurst VJ, Elzea JM. 1997. The 11th Int Clay Conf Guidebook for the Kaolin Field Trip to the Macon Area, Georgia. Ottawa, CA: Carleton Univ. 12 p.

  • Hurst VJ, Crawford TJ, Sandy J. 1966. Mineral Resources of the Central Savannah River Area. Washington, DC: US Dept Commerce. 467 p.

    Google Scholar 

  • Hurst VJ, Kunkle AC, Smith JM, Pickering SM, Jr, Shaffer ME, Smith RP, Williamson JW 1979. Field conference on kaolin, bauxite, and fullers earth. Annu Meet Clay Miner Soc. 107 p.

    Google Scholar 

  • Hurst VJ, Pickering SM, Jr. 1989a. Cretaceous-Tertiary strata and kaolin deposits in the Inner Coastal Plain of Georgia. Field Trip Guidebook T172 of the 28fh International Geologic Congress. Washington, DC: Amer Geophys Union, p 2–22.

    Google Scholar 

  • Hurst VJ, Pickering SM, Jr. 1989b. Significance of crystallite size and habit in determining origin and industrial applications of Georgia kaolins. Geol Soc Southeast Section. Abstracts with programs, p 22.

    Google Scholar 

  • Hurst VJ, Rigsby WE. 1984. Intergrowths and aggregates of natural kaolinite. In: Bailey GW, editor. Proc 42nd Annu Meet Electron Microscopy Soc Am. San Francisco: San Francisco Pr. p 22–23.

  • Jonas EE. 1964. Petrology of the Dry Branch, Georgia, kaolin deposits. Bailey WF, editor. Proc 12th Natl Clay Miner Soc Conf: 1963, New York: Macmillan. p 195–205.

  • Jones T. 1988. Smectitic impurities in some commercial Georgia kaolins [M.S. thesis]. Athens, GA: Univ Georgia. 60 p.

    Google Scholar 

  • Jorgensen BB. 1982. Ecology of the bacteria of the sulfur cycle with special reference to anoxic-oxic interface environments. London: Philos Trans Royal Soc B 298:543–561.

    Google Scholar 

  • Kesler TL. 1963. Environment and origin of the Cretaceous kaolin deposits of Georgia and South Carolina. Ga Miner Newsletter 1, 2:1–11.

    Google Scholar 

  • Ladd GE. 1898. A preliminary report on a part of the clays of Georgia. Ga Geol Surv Bull 6-A. 204 p.

    Google Scholar 

  • LeGrand HE, Furcron AS. 1956. Geology and groundwater resources of Central-East Georgia. Ga Geol Surv Bull 64. 174 p.

  • Lovley DR, Chapelle FW, Phillips EJP. 1990. Fe(III)-reducing bacteria in deeply buried sediments of the Atlantic Coastal Plain. Geology 18:954–957.

    Article  Google Scholar 

  • Lovley DR, Phillips EJP. 1987. Competitive mechanisms for inhibition of sulfate reduction and methane production in the zone of ferric iron reduction in sediments. Appl Environ Microbiol 53:2636–2641.

    Google Scholar 

  • Lowe RA. 1991. Microtextural and mineralogic differences of Georgia’s kaolins and the search for Ostwald Ripening [M.S. thesis]. Athens, GA: Univ Georgia. 81 p.

    Google Scholar 

  • Margulis L, Sagan D. 1986. Microcosmos, four billion years of evolution from our microbial ancestors. New York: Summit Books. 301 p.

    Google Scholar 

  • Martin RT, chair. 1991. Report of the CMS Nomenclature Committee. Revised classification of clay materials. Clays Clay Miner 39:333–335.

    Article  Google Scholar 

  • Melear ND. 1990. Clay minerals and ferruginous minerals formed during weathering of granitic rocks of the Georgia Piedmont [M.S. thesis]. Athens, GA: Univ Georgia. 69 p.

    Google Scholar 

  • Millman N, Iannicelli J. 1966. Relation of viscosity of kaolin-water suspensions to montmorillonite content of certain Georgia clays. Proc 14th Natl Conf Clays Clay Miner. Berkeley, CA. p 347–354.

    Google Scholar 

  • Millot G. 1970. Geology of clays NY: Springer-Verlag. 429 p.

    Book  Google Scholar 

  • Mitzutani S. 1970. Silica minerals in the early stage of diagenesis. Sedimentology 16:419–436.

    Article  Google Scholar 

  • Patterson SH, Buie BE 1974. Field conference on kaolin and fullers earth. Ga Geol Surv Guidebook 14. 53 p.

  • Patterson SH, Murray HH. 1984. Kaolin, refractory clay, ball clay, and halloysite in North America, Hawaii, and the Caribbean region. USGS Prof Paper 1306. 56 p.

    Google Scholar 

  • Pettijohn FJ. 1949. Sedimentary rocks. New York: Harper Bros. 526 p.

    Google Scholar 

  • Pickering SM, Jr, Hurst VJ. 1989. Commercial kaolins in Georgia, occurrence, mineralogy, origin, and use. In: Fritz WJ, editor. Excursions in Georgia geology. Atlanta, GA: Geol Soc Am Guidebooks 9(1):29–75.

    Google Scholar 

  • Rogers LE 1979. The petrology-mineralogy of six Georgia kaolins [Ph.D. dissertation]. Athens, GA: Univ Georgia. 234 p.

    Google Scholar 

  • Schroder CH. 1982. Trace fossils of the Oconee Group and basal Barnwell Group of East-Central Georgia. Ga Geol Surv Bull 88. 125 p.

  • Siffert B. 1962. Quelques réactions de la silice en solution: La formation des argiles. Memoires du Service de la Carte Géologique D’Alsace et de Lorraine No 21. Strasbourg: Univ Strasbourg. 86 p.

    Google Scholar 

  • Smith RW. 1929. Sedimentary kaolins of the Coastal Plain of Georgia. Ga Geol Surv Bull 44. 474 p.

  • Toth J. 1963. A theoretical analysis of groundwater flow in small drainage basins. J Geophys Res 68:4795–4812.

    Article  Google Scholar 

  • Tschudy RH, Patterson SH. 1975. Palynological evidence for Late Cretaceous, Paleocene, and Early and Middle Eocene for strata in the kaolin belt, Central Georgia. J Res USGS 3:437–445.

    Google Scholar 

  • Veatch O. 1909. Second report on the clay deposits of Georgia. Ga Geol Surv Bull 18. 453 p.

  • Weaver CE. 1989. Clays, muds, and shales. New York: Elsevier Science. 819 p.

    Google Scholar 

  • Webb H, Sprague EK. 1991. Timing of kaolinization in hard kaolins of the Huber Formation in central and eastern Georgia: Trace fossil microtextures documented by scanning electron microscopy. Program and Abstracts for 28th Annu Meet Clay Miner Soc; Houston, TX. p. 171.

    Google Scholar 

  • Westrich JT. 1983. The consequences and controls of bacterial sulfate reduction in marine sediments [Ph.D. dissertation]. New Haven, CT: Yale Univ 530 p.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hurst, V.J., Pickering, S.M. Origin and Classification of Coastal Plain Kaolins, Southeastern USA, and the Role of Groundwater and Microbial Action. Clays Clay Miner. 45, 274–285 (1997). https://doi.org/10.1346/CCMN.1997.0450215

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1346/CCMN.1997.0450215

Key Words

Navigation