Skip to main content Accessibility help

Modern carbonate marine-sands in estuaries of southwest England

  • J. R. Merefield (a1)

Large deposits of marine-sand occur in the Taw, Camel and Hayle estuaries of north Devon and Cornwall. Total carbonate concentrations reach 67% in the Hayle, 62% in the Camel, and 40% in the Taw. Well mixed, the sands contain modern skeletal debris of consistent composition, which persists up to 18 km and 12 km landward from the mouths of the Taw and Camel estuaries. Although primarily a molluscan sand, remains of barnacles, bryozoans, echinoids, foraminifera, sponge spicules, decapods and coralline algae are common. Carbonate mineralogy provided by these components (on a 100% carbonate basis) consists of 45% aragonite, 38% low Mg-calcite and 17% high Mg-calcite. Two estuaries of the southeast coast of Devon (the Exe and Teign) contain smaller carbonate concentrations of up to 9 and 14%. Values are low there owing to dilution by readily eroded cliff-talus from local exposures of New Red Sandstone. These Permo-Triassic sediments provide carbonate lithoclasts, however, which supplement the modern biogenic supply. Strontium values have been used to estimate the extent of carbonate lithoclasts supplied to the Exe and Teign. The present source of marine-sand of estuaries in southwest England is considered to be mostly near-shore detritus supplemented by eroded cliff-talus, derived largely from local outcrops. Once this material enters the estuarine regime it is available as a supply of sediment for further up-estuary transport.

Hide All
Banner, F. T. 1979. Sediments of the north-western European shelf. Elsevier Oceanography Series vol. 24 A, pp. 271300.
Belderson, R. H., Kenyon, N. H. & Stride, A. H. 1971. Holocene sediments on the continental shelf west of the British Isles. In ICSU/SCOR Working Party 31 Symposium, Cambridge 1970: The Geology of East Atlantic Continental Margin, vol. 2. Europe (ed. Delany, F. M.). Inst. Geol. Sci. Rept. no. 70/14, pp. 161–70.
Blackmon, P. D. & Todd, R. 1959. Mineralogy of some foraminifera as related to their classification and ecology. J. Paleont. 33, 115.
Bouysse, P., Lann, F. L. & Scolari, G. 1979. Les sédiments superficiels des approches occidentales de La Manche. Mar. Geol. 29, 107–35.
Channon, R. D. & Hamilton, D. 1976. Wave and tidal current sorting of shelf sediments southwest of England. Sedimentology 23, 1742.
Chave, K. E. 1952. A solid solution between calcite and dolomite. J. Geol. 60, 190–2.
Chave, K. E. 1964. Skeletal durability and preservation. In Approaches to Paleoecology (ed. Imbrie, J. and Newell, N. D.), pp. 377–87. New York: John Wiley.
Codrington, T. 1898. On some submerged rock valleys in south Wales, Devon and Cornwall. Q. Jl geol. Soc. Lond. 54, 251–78.
Cosgrove, M. E. 1973. The geochemistry and mineralogy of the Permian Red Beds of southwest England. Chem. Geol. 11, 3147.
Culver, S. J. 1980. Differential two-way sediment transport in the Bristol Channel and Severn Estuary, U.K. Mar. Geol. 34, M 3943.
Culver, S. J. & Banner, F. T. 1979. The significance of derived pre-Quaternary foraminifera in Holocene sediments of the northcentral Bristol Channel. Mar. Geol. 29, 187207.
De La Beche, H. T. 1839. Report on the geology of Cornwall, Devon and west Somerset. Mem. geol. Surv. U.K.
Donovan, D. T., Savage, R. J. G., Stride, A. H. & Stubbs, A. R. 1961. Geology of the floor of the Bristol Channel. Nature, Lond. 189, 51–2.
Driscol, E. G. 1967. Experimental field study of shell abrasion. J. sedim. Petrol. 37, 1117–23.
Durrance, E. M. 1969. The buried channels of the Exe. Geol. Mag. 106, 174–89.
Durrance, E. M. 1971. The buried channel of the Teign estuary. Proc. Ussher Soc. 2, 299306.
Edmonds, E. A., Williams, B. J. & Taylor, R. T. 1979. Geology of Bideford and Lundy Island. Mem. geol. Surv. U.K.
Evans, D. J. & Thompson, M. S. 1979. The geology of the central Bristol Channel and the Lundy area, Southwestern Approaches, British Isles. Proc. Geol. Ass. 90, 120.
Force, L. M. 1969. Calcium carbonate size distribution on the west Florida shelf and experimental studies on the microarchitectural control of skeletal breakdown. J. sedim. Petrol. 39, 902–34.
Gavish, E. & Friedman, G. M. 1973. Quantitative analysis of calcite and Mg-calcite by X-ray diffraction: effect of grinding on peak height and peak area. Sedimentology 20, 437–48.
Goldsmith, J. R., Graf, D. L. & Heard, H. C. 1961. Lattice constants of the calcium-magnesium carbonates. Am. Miner. 46, 453–7.
Guilcher, A. 1964. La sédimentation sous-marine dans la partie orientale de la Rade de Brest, Bretagne. In Developments in Sedimentology, vol. 1 (ed. Straaten, L. M. J. U. van), pp. 148–56.
Hallam, A. & Price, N. B. 1968. Environmental and biochemical control of strontium in shells of Cardium edule. Geochim. cosmochim. Acta. 32, 319–28.
Hamilton, D., Sommerville, J. H. & Stanford, P. N. 1980. Bottom currents and shelf sediments, southwest of Britain. Sediment. Geol. 26, 115–38.
Hawkins, A. B. 1971. Sea level changes around southwest England. Colston Pap. 23, 6788.
Hjulström, F. 1935. Studies of the morphological activity of rivers as illustrated by the River Fyris. Bull. geol. Instn. Univ. Uppsala. 25, 221527.
Hosking, K. F. G. & Ong, P. 1963. The distribution of tin and certain other heavy metals in the superficial portions of the Gwithian/Hale beach of west Cornwall. Proc. Ussher Soc. 1, 41–3.
Inglis, C. C. & Allen, F. H. 1957. The regimen of the Thames estuary as affected by currents, salinities’ and river flow. Proc. Instn. civ Engrs. 7, 827–78.
Jones, W. C. & Jenkins, D. A. 1970. Calcareous sponge spicules: a study of magnesian calcites. Calcif. Tissue Res. 4, 314–29.
Kenyon, N. H. & Stride, A. H. 1970. The tide-swept continental shelf sediments of the Shetland Islands and France. Sedimentology 14, 159–73.
Lees, A. 1975. Possible influence of salinity and temperature on modern shelf carbonate sedimentation. Mar. Geol. 19, 159–98.
Leonard, J. E., Cameron, B., Pilkey, O. H. & Friedman, G. M. 1981. Evaluation of cold-water carbonates as a possible paleoclimatic indicator. Sediment. Geol. 28, 128.
MacFarlane, P. B. 1955. Survey of two drowned river valleys in Devon. Geol. Mag. 92, 419–29.
Meade, R. H. 1969. Landward transport of bottom sediments in estuaries of the Atlantic Coastal Plain. J. sedim. Petrol. 39, 222–34.
Meade, R. H. 1972. Transport and deposition of sediments in estuaries. Mem. geol. Soc. Am. 133, 91120.
Merefield, J. R. 1976. Barium build-up in the Teign Estuary. Mar. Pollut. Bull. 7, 214–16.
Merefield, J. R. 1978. Trace elements as indicators of sediments transport in some estuaries of south-west England. (Abstract). Proc. Ussher Soc. 4, 219.
Merefield, J. R. 1981(a). Littoral carbonates of south-west England: preliminary observations on mineralogy and geochemistry. Proc. Ussher Soc. 5, 235–7.
Merefield, J. R. 1981(b). Caesium in the up-estuary transport of sediments. Mar. Geol. 39, M 4555.
Milliman, J. D. 1974. Marine Carbonates: Recent Sedimentary Carbonates, vol. 1. Berlin, Heidelberg, New York: Springer Verlag.
Milliman, J. D. & Bornhold, B. D. 1973. Peak height versus peak intensity analysis of X-ray diffraction data. Sedimentology 20, 445–8.
Milliman, J. D., Gastner, M. & Muller, J. 1971. Utilization of magnesium in coralline algae. Bull. geol. Soc. Am. 82, 573–80.
Murray, J. W. & Hawkins, A. B. 1976. Sediment transport in the Severn estuary during the past 8000–9000 years. J. geol. Soc. Lond. 132, 385–98.
Murray, J. W., Sturrock, S. & Western, J. 1982. Suspended load transport of foraminiferal tests in a tide-and wave-swept sea. J. Foraminer. Res. 12, 5165.
Noll, W. 1934. Geochemie des Strontiums mit Bemerkungen zur Geochemie des Bariums. Chem. Erde 8, 507–60.
Norrish, K. & Hutton, J. T. 1964. Preparation of samples for analysis by X-ray fluorescent spectrography. C.S.I.R.O. Division of Soils. Report 3/64, Adelaide.
Postma, H. 1967. Sediment transport and sedimentation in the estuarine environment. In Estuaries (ed. Lauff, G. H.), pp. 158–79. Am. Assoc. Adv. Sci. Pub. 83.
Rucker, J. B. & Valentine, J. W. 1961. Salinity response of trace element concentration in Grassostrea virginica. Nature, Lond. 190, 1099–100.
Salmon, R. 1973. Builders take away the Cornish coast. Observer Mag. 22/4, 35.
Schopf, T. J. M. & Manheim, F. T. 1967. Chemical composition of Ectoprocta (Bryozoa). J. Paleont. 41, 1197–225.
Sollas, W. J. 1883. The estuaries of the Severn and its tributaries: an enquiry into the nature and origin of their tidal sediment and alluvial flats. Q. J. geol. Soc. Lond. 39, 611–26.
Spratt, T. 1856. An Investigation of the Movements of Teignmouth Bar. London.
Stuart, A. & Simpson, B. 1936. The shore sands of Cornwall & Devon from Land's End to the Taw-Torridge estuary. R. geol. Soc. Corn. 17, 1340.
Thomas, J. M. 1980. Sediments and sediment transport in the Exe estuary. In Essays on the Exe Estuary (ed. Boalch, G. T.), pp. 7387. Exeter: Devon Ass. Special Vol. 2.
Vanny, J. R. 1965. Etude sédimentologique du Mor Bras, Bretagne. Mar. Geol. 3, 195222.
Vinogradov, A. P. 1953. The elementary chemical composition of marine organisms. Sears Found. Marine Res. Mem. II.
Yim, W. W. S. 1976. Heavy metal accumulation in estuarine sediments in a historical mining area of Cornwall. Mar. Pollut. Bull. 7, 147–50.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Geological Magazine
  • ISSN: 0016-7568
  • EISSN: 1469-5081
  • URL: /core/journals/geological-magazine
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed