Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-23T16:15:42.919Z Has data issue: false hasContentIssue false
  • English
  • Français

Preservation of shell microstructure in silicified brachiopods from the Upper Cretaceous Wilmington Sands of Devon

Published online by Cambridge University Press:  01 May 2009

H. K. Holdaway  and
C. J. Clayton
H. K. Holdaway
Affiliation:
Department of GeologyUniversity of LondonKing's CollegeThe StrandLondon WC2R 2LS.
C. J. Clayton
Affiliation:
Department of GeologyUniversity of LondonKing's CollegeThe StrandLondon WC2R 2LS.
Get access Rights & Permissions [Opens in a new window]

Summary

From a study of silicified fossils, and in particular the microstructure of brachiopods, from the Wilmington Sands (Upper Cretaceous) of Devon, a model of skeletal silicification is proposed. Three distinct morphologies of silica were formed, controlled by the relative rates of silica supply and carbonate dissolution: (a) a fine-scale replacement of the original shell microstructure where silica was abundant; (b) a concentric ring morphology called ‘beekite’ where silica supply was limited, and (c) a granular white crust formed where carbonate dissolution was restricted. Silicification occurred during early diagenesis as a result of bacterial decay of organic matter intimately associated with skeletal fragments, within a sediment of restricted permeability. A build-up of CO2 probably caused dissolution of skeletal carbonate, and bicarbonate released from this caused local precipitation of silica. The proposed mechanism is belived to be of general applicability to micrite-rich carbonate sediments.

Type
Articles
Information
Geological Magazine , Volume 119 , Issue 4 , July 1982 , pp. 371 - 382
Copyright
Copyright © Cambridge University Press 1982

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

Berner, R. A. 1971. Principles of Chemical Sedimentology. New York: McGraw-Hill.Google Scholar
Berner, R. A. 1980. Early diagenesis – a theoretical approach. Princeton: Princeton University Press.Google Scholar
Brunton, C. H. C. 1966. Silicified productids from the Visean of County Fermanagh. Bull. Br. Mus. Nat. Hist. 12, 173–243.Google Scholar
Calvert, S. E. 1973. Nature of silica phases in deep sea cherts of the North Atlantic. Nature (Phys. Sci.) 234, 133–4.CrossRefGoogle Scholar
Carpenter, M. D. 1851. On the intimate structure of the shells of the Brachiopoda. In Davidson, British fossil Brachiopoda, 1. Palaeontogr. Soc, London (Monogr.).Google Scholar
Carter, D. J. & Hart, M. B. 1977. Aspects of mid-Cretaceous stratigraphical micropalaeontology. Bull. Br. Mus. Nat. Hist. (ser. Geol.), 29, 1–35.Google Scholar
Chowns, T. M. & Elkins, J. E. 1974. The origin of quartz geodes and cauliflower cherts through the silicification of anhydrite nodules. J. sedimen. Petrol. 44, 885–903.Google Scholar
Coleman, M. L. & Raiswell, R. 1981. Carbon, oxygen and sulphur isotope variations in concretions from the Upper Lias of N.E. England. Geochim. cosmochim. Acta 34, 329–40.CrossRefGoogle Scholar
Cooper, G. A. & Grant, R. E. 1972. Permian brachiopods of west Texas. Smithson. Contr. Paleobiol. 14.CrossRefGoogle Scholar
Emerson, R. J., Jahnke, R., Bender, M., Froelich, P., Klinkhammer, G., Bowser, C. & Setlock, G. 1980. Early diagenesis in sediments from the eastern equatorial Pacific. 1. Pore water nutrient and carbonate results. Earth Planet. Sci. Lett. 49, 57–80.CrossRefGoogle Scholar
Folk, R. L. & Pitman, J. S. 1971. Length slow chalcedony; a new testament for vanished evaporites. J. sedimen. Petrol. 41, 1045–58.Google Scholar
Folk, R. L. & Weaver, C. E. 1952. A study of the texture and composition of chert. Am. J. Sci. 250, 498–510.CrossRefGoogle Scholar
Francis, S., Barghoorn, E. S. & Margulis, L. 1978. On the experimental silicification microorganisms. III. Implications of the preservation of the green prokaryotic alga Prochloron and other coccoids for the interpretation of the microbial fossil record. Precambrian Res. 7, 377–83.CrossRefGoogle Scholar
Francis, S., Margulis, L. & Barghoorn, E. S. 1978. On the experimental silicification of microorganisms. II. On the time of appearance of eukaryotic organisms in the fossil record. Precambrian Res. 6, 65–100.CrossRefGoogle Scholar
Froelich, P. N., Klinkhammer, G. P., Bender, M. L., Luedtke, N. A., Heath, G. R., Cullen, D., Daulphin, P. & Hammond, D. 1979. Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic: suboxic diagenesis. Geochim. cosmochim. Acta 43, 1075.CrossRefGoogle Scholar
Hauser, E. A. 1955. Silicic Science. New York: Van Nostrand.Google Scholar
Hedges, E. S. 1932. Liesegang Rings and Other Periodic Structures. London: Champman & Hall.Google Scholar
Hughs, T. 1889. On the manner of occurrence of beekite and its bearing upon the origin of siliceous beds of Palaeozoic age. Mineralog. Mag. 8, 265–71.Google Scholar
Iler, R. K. 1979. The Chemistry of Silica; Solubility, Polymerisation, Colloid and Surface Properties and Biochemistry. Chichester: Wiley & Sons.Google Scholar
Irwin, H., Coleman, M. L. & Curtis, C. D. 1977. Isotopic evidence for source of diagenetic carbonates formed during burial of organic-rich sediments. Nature, Lond. 269, 209–13.CrossRefGoogle Scholar
Jacka, A. D. 1974. Replacement of fossils by length slow chalcedony and associated dolomitization. J. sedimen. Petrol. 44, 421–7.Google Scholar
Jukes-Brown, A. J. & Hill, W. 1903. The Cretaceous rocks of Britain. Vol. 2. The Lower and Middle Chalk of England. Mem. Geol. Surv. U.K.Google Scholar
Kennedy, W. J. 1970. A correlation of the uppermost Albian and the Cenomanian of south west England. Proc. Geol. Ass. 81, 613–77.CrossRefGoogle Scholar
Kitano, Y., Okumura, M. & Idogaki, M. 1979. Behaviour of dissolved silica in parent solution at the formation of calcium carbonate. Geochem. J. 13, 253–60.CrossRefGoogle Scholar
Knauth, L. P. & Epstein, S. 1976. Hydrogen and oxygen isotope ratios in nodular and bedded cherts. Geochim. cosmochim. Acta, 40, 1095–1108.CrossRefGoogle Scholar
Leo, R. F. & Barghoorn, E. S. 1976. Silicification of wood. Leafl. Harvard Univ. Bot. Mus. 25, 1–47.CrossRefGoogle Scholar
Mathews, A. 1972. Crystallisation of quartz from silicic acid: a kinetic investigation using sodium carbonate solutions. In Progress in Experimental Petrology, vol. 2 (ed. Henderson, C. M. B. & Hamilton, D. L.), pp. 2–65.Google Scholar
Orme, G. R. 1974. Silica in the Visean limstones of Derbyshire, England. Proc. Yorks. geol. Soc. 5, 63–104.Google Scholar
Pelto, C. R. 1956. A study of chalcedony. Am. J. Sci. 254, 32–50.CrossRefGoogle Scholar
Redfield, A. C. 1958. The biological control of chemical factors in the environment. Am. Sci. 46, 206–26.Google Scholar
Rio, M. & Chalamet, A. 1980. Relations entre l'habitus de la dimension des crystallites et le comportement thermique de la silice dans divers types d'accidents siliceus. Bull. Mineral. 103, 44–47.Google Scholar
Siever, R., Beck, K. C. & Berner, R. A. 1965. Composition of interstitial waters of modern sediments. J. Geol. 73, 39–73.CrossRefGoogle Scholar
Smith, W. E. 1961. The detrital mineralogy of the Cretaceous rocks of south east Devon with particular reference to the Cenomanian. Proc. Geol. Ass. 72, 303–31.CrossRefGoogle Scholar
Tarr, W. A. 1938. Terminology of the chemical siliceous sediments. Rep. Comm. Sedim. 1937–38, Nat. Res. Council, 8–27.Google Scholar
White, J. F. & Corwin, J. F. 1961. Synthesis and origin of chalcedony. Am. Miner. 46, 112–19.Google Scholar
Williams, A. 1968. Evolution of the shell structure of articulate brachipods. Spec. Pap. Palaeontol. London 2.Google Scholar
Wilson, R. C. L. 1966. Silica diagenesis in Upper Jurassic limestones of southern England. J. sedimen. Petrol. 36, 1036–49.Google Scholar
Schmitt, J. G. & Boyd, D. W. 1981. Patterns of silicification in Permian pelecypods and brachiopods from Wyoming. J. sedim. Petrol. 51, 1297–308.Google Scholar