Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-24T16:35:13.141Z Has data issue: false hasContentIssue false
  • English
  • Français

A seismic refraction line across Norfolk

Published online by Cambridge University Press:  01 May 2009

P. N. Chroston
P. N. Chroston
Affiliation:
School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, U.K.
Get access Rights & Permissions [Opens in a new window]

Abstract

A simple seismic refraction line some 115 km long has been made across Norfolk to provide constraints on the depth to the ‘igneous/metamorphic’ basement. Shots were fired in the Wash and off the coast near Lowestoft and attempts were made to record at approximately 2 km intervals along the line. Recording quality was only fair, resulting in incomplete coverage of the line, and this restricts the quality of interpretation. The results show a refractor of about 6.05 km s−1 revealed over the whole line with no first-arrival evidence of the 4.5–5.5 km s−1 velocity expected from Palaeozoic sediments. Using estimated velocities of 2.4 km s−1 for the post-Palaeozoic succession, 4.5–5.5 km s−1 for the Palaeozoic succession and an estimated sub-crop position of the basement on the sub-Mesozoic floor, models are produced which suggest that the Palaeozoic sediments are no more than 600–1500 m thick at the eastern end of the line, depending on the Palaeozoic velocity assumed.

Type
Articles
Information
Geological Magazine , Volume 122 , Issue 4 , July 1985 , pp. 397 - 401
Copyright
Copyright © Cambridge University Press 1985

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

Bullard, E. C., Gaskell, T. F., Harland, W. B. & Kerr-Grant, C. 1940. Seismic investigations of the Palaeozoic floor of East England. Philosophical Transactions of the Royal Society of London A 239 (800), 29–94.Google Scholar
Bullerwell, W. 1957. Wash and East Anglia. Magnetic Survey. Summary of Progress of the Geological Survey of Great Britain for 1956, p. 64.Google Scholar
Chroston, P. N. & Sola, M. A. 1975. The sub-Mesozoic floor in Norfolk. Bulletin of the Geological Society of Norfolk, 1–22.Google Scholar
Chroston, P. N. & Sola, M. A. 1982. Deep boreholes, seismic refraction lines, and the interpretation of gravity anomalies in Norfolk. Journal of the Geological Society of London 139, 255–64.CrossRefGoogle Scholar
Institute of Geological Sciences. 1965. Aeromagnetic map of Great Britain and Northern Ireland. Sheet 2. Southampton: Ordnance Survey.Google Scholar
Institute of Geological Sciences. 1981. East Anglia Bouguer Anomaly Map 1:250,000. Southampton: Ordnance Survey.Google Scholar
Kent, P. E. 1968. The buried floor of Eastern England. In The Geology of the East Midlands (eds. Sylvester, Bradley and Ford, ), pp. 112–37. Leicester University Press.Google Scholar
Le bas, M. J. 1972. Caledonian igneous rocks beneath Central and Eastern England. Proceedings of the Yorkshire Geological Society 39, 71–86.CrossRefGoogle Scholar
Linsser, H. 1968. Transformation of magnetometric data into tectonic maps by digital template analysis. Geophysical Prospecting 16, 170–207.CrossRefGoogle Scholar
Strahan, A. 1913. Boring at the East Anglian Ice Co.'s Works, Lowestoft. Summary of Progress of the Geological Survey of Great Britain for 1912, pp. 87–8.Google Scholar
Wills, L. J. 1978. A palaeogeographical map of the lower Palaeozoic floor below the cover of Upper Devonian, Carboniferous, and other formations. Memoir Geological Society of London, no. 8.Google Scholar