Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-30T03:52:01.611Z Has data issue: false hasContentIssue false
  • English
  • Français

Diagenesis, porosity and permeability in the Corallian Beds (Upper Oxfordian) from the Harwell Research Site, South Oxfordshire, UK

Published online by Cambridge University Press:  09 July 2018

A. E. Milodowski  and
R. D. Wilmot
A. E. Milodowski
Affiliation:
British Geological Survey, Keyworth, Nottingham NG12 5GG
R. D. Wilmot
Affiliation:
4 Gray's Inn Road, London WC1X 8NG
Get access Rights & Permissions [Opens in a new window]

Abstract

The Corallian Beds beneath the Harwell Research Site, south Oxfordshire, are a highly variable sequence of sandstones, mudstones and limestones. The more permeable lithologies of the upper part of the sequence constitute an important local aquifer. Diagenetic and post-lithification processes have strongly influenced the porosity, permeability and mineralogy of the aquifer rocks. Calcite cementation reduced the porosity and permeability of the sandstones and limestones in the upper part of the aquifer. Cementation occurred in at least three stages ranging from early diagenesis to post-compactional diagenesis. Late-stage dissolution of calcite took place along fractures and bedding discontinuities, restoring the porosity and permeability of these sediments and developing secondary porosity and permeability where original clastic carbonate was removed. Invasion of the Corallian porewaters by waters charged with CO2 is postulated as a mechanism by which calcite was removed. At the base of the aquifer, early diagenetic dissolution of biogenic silica created a high secondary porosity. Silica was reprecipitated in the dissolution voids and matrix as opal-CT. Authigenic smectite and zeolites are also associated with opal-CT. These phases are believed to have precipitated from pore-waters rich in ions derived from the alteration of volcanogenic detritus associated with the Corallian sediments.

Type
Research Article
Information
Clay Minerals , Volume 19 , Issue 3 , June 1984 , pp. 323 - 341
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1984

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

Ashby, D.A. & Pearson, M.J. (1978) Mineral distributions in sediments associated with the Alton Marine Band near Penistone, South Yorkshire. Proc. 6 th Int. Clay Conf. Oxford, 311-321.Google Scholar
Bathhurst, R.C. (1975) Carbonate Sediments and their Diagenesis. Elsevier, Amsterdam.Google Scholar
Berner, R.A. (1971) Principles of Chemical Sedimentology. McGraw-Hill, New York.Google Scholar
Brookfield, M. (1973) Palaeogeography of the Upper Oxfordian and Lower Kimmeridgian (Jurassic) in Britain. Palaegeogr., Palaeoclimatol., Palaeoecol. 14, 137–167.Google Scholar
Brown, G., Catt, J.A. & Weir, A.H. (1969) Zeolites of the clinoptilolite-heulandite type in sediments of south-east England. Mineral. Mag. 37, 480–488.CrossRefGoogle Scholar
Calvert, S.E. (1973) Nature of silica phases in deep-sea cherts of the North Atlantic. Nature (Phys. Sci.) 234, 133–134.CrossRefGoogle Scholar
Chowdhury, A.N. (1982) Smectite, zeolite, biotite and apatite in the Corallian (Oxfordian) sediments of the Baulking area in Berkshire England. Geol. Mag. 119, 487–496.Google Scholar
Curtis, C.D. (1967) Diagenetic iron minerals in some British Carboniferous sediments. Geochim. Cosmochim. Acta 31, 2109–2123.Google Scholar
Davies, P.J. (1971) Calcite precipitation and recrystaiiization fabrics—their significance in Jurassic limestones of Europe. J. Geol. Soc. Australia 18, 279–292.Google Scholar
Deer, W.A., Howie, R.A. & Zussman, J. (1962) Rock Forming Minerals: Vol. 5, Non-silicates. Longmans, London.Google Scholar
Dickson, J.A.D. (1965) A modified staining technique for carbonates in thin-section. Nature 205, 587.Google Scholar
Dickson, J.A.D. (1966) Carbonate identification and genesis as revealed by staining. J. Sed. Petrol. 36, 491–505.Google Scholar
Ellis, A.T. (1981) The porosity and permeability of the aquifer units of borehole HW3, Harwell. Rep. Inst. Geol. Sci. Hydrogeology Unit, WD/ST/81/8.Google Scholar
Freeze, R.A. & Cherry, J.A. (1979) Groundwater. Prentice Hall, New Jersey.Google Scholar
Hudson, J.D. (1978a) Concretions, isotopes and the diagenetic history of the Oxford Clay (Jurassic) of Central England. Sedimentology 25, 339–370.Google Scholar
Hudson, J.D. (1978b) Pyrite in ammonite shells and shales. Neus. Jahrb. Geol. Palaeont. Abh. 157, 190–193.Google Scholar
Irwin, H. (1980) Early diagenetic carbonate precipitation and pore-fluid migration in the Kimmeridge Clay of Dorset, England. Sedimentology 27, 577–591.Google Scholar
Jeans, C.V. (1978) Silicifications and associated clay assemblages in the Cretaceous marine sediments of southern England. Clay Miner. 13, 101–126.Google Scholar
Jeans, C.V. (1980) Early submarine lithification in the Red Chalk and the Lower Chalk of eastern England: a bacterial control model and its implications. Proc. Yorks. Geol. Soc. 43, 81–157.Google Scholar
Jeans, C.V., Merriman, R.J., Mitchell, J.G. & Bland, D.J. (1982) Volcanic clays in the Cretaceous of southern England and Northern Ireland. Clay Miner. 17, 105–156.Google Scholar
Kastner, M., Keen, J.B. & Gieskes, J.M. (1977) Diagenesis of siliceous oozes—I. Chemical controls on the rate of opal-A to opal-CT transformation—an experimental study. Geochim. Cosmochim. Acta 41, 1041–1059.Google Scholar
Milodowski, A.E. Martin, B.A. & Wilmot, R.D. (1982) Petrography of the Cretaceous core from the Harwell Research Site. Rep. Inst. Geol. Sci., ENPU 82-14, 83 pp.Google Scholar
Milodowski, A.E. & Wilmot, R.D. (1983) The petrography of the Jurassic core from the Harwell Research Site. Part 1 : Kimmeridge Clay, Corallian Beds and Oxford Clay. Rep. Inst. Geol. Sci., FLPU 83-9, 110 pp.Google Scholar
Pearson, M.J. (1979) Geochemistry of the Hepworth Carboniferous sediment sequence and the origin of the diagenetic iron minerals and concretions. Geochim. Cosmochim. Acta 43, 927–941.Google Scholar
Pyzik, A.J. & Sommer, S.E. (1981) Sedimentary iron monosulphides: kinetics and mechanism of formation. Geochim. Cosmochim. Acta 45, 687–698.Google Scholar
Robins, N.S., Martin, B.A. & Brightman, M.A. (1981) Borehole drilling and completion details for the Harwell Research Site. Rep. Inst. Geol. Sci., ENPU 81-9, 28 pp.Google Scholar
Talbot, M.R. (1973) Major sedimentory cycles in the Corallian Beds (Oxfordian) of Southern England. Palaeogeogr., Palaeoclimatol., Palaeocol. 14, 293–317.Google Scholar
Talbot, M.R. (1974) Ironstones in the Upper Oxfordian of southern England. Sedimentology 21, 433–450.Google Scholar
Waugh, B. (1978) Authigenic K-feldspar in British Permo-Triassic sandstones. J. Geol. Soc. London 135, 51–56.Google Scholar
Wilmot, R.D. & Morgan, D.J. (1982) Mineralogical and lithochemical studies of strata beneath the Harwell Research Site. Rep. Inst. Geol. Sci., ENPU 82-13, 34 pp.Google Scholar
Wilson, R.C.L. (1966) Silica diagenesis in upper Jurassic limestones of southern England. J. Sed. Petrol. 36, 1036–1049.Google Scholar
Wilson, R.C.L. (1968a) Upper Oxfordian palaeogeography of southern England. Palaeogeogr. Palaeoclimatol, Palaeoecol. 4, 5–28.Google Scholar
Wilson, R.C.L. (1968b) Carbonate facies variation within the Osmington Oolite Series in southern England. Palaeogeogr., Palaeoclimatol, Palaeoecol. 4, 89–123.Google Scholar
Wise, S.W. & Kelts, K.P. (1972) Inferred diagenetic history of a weakly silicified deep-sea chalk. Trans. Gulf Coast Ass. Geol. Socs. 22, 177–203.Google Scholar
Wright, J.K. (1981) The Corallian rocks of north Dorset. Proc. Geol. Ass. 92, 17–32.Google Scholar