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Integrated geophysical/geological modelling of the Caledonian and Precambrian basement of southern Britian

Published online by Cambridge University Press:  01 May 2009

J. P. Busby ,
G. S. Kimbell  and
T. C. Pharaoh
J. P. Busby
Affiliation:
British Geological Survey, Keyworth, Nottingham NG12 5GG, U.K.
G. S. Kimbell
Affiliation:
British Geological Survey, Keyworth, Nottingham NG12 5GG, U.K.
T. C. Pharaoh
Affiliation:
British Geological Survey, Keyworth, Nottingham NG12 5GG, U.K.
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Abstract

Quantitative modelling of potential field data has been used to test and extend geological sections constructed for the new British Geological Survey Tectonic Map of Britain and Ireland. Three of the profiles cross part of the Anglo-Brabant Massif and provide new information on the nature of the pre-Mesozoic basement. A profile across southern England (passing just to the west of London) suggests that a significant contribution to observed gravity variations in the region results from changes in the thickness of relatively low density Lower Palaeozoic rocks. It also identifies a major deep-seated body with relatively high magnetic susceptibility and low density which is interpreted as a Precambrian cratonic core underlying the southeastern part of the Midlands Microcraton. Profiles across central and eastern England reveal major boundaries within the Precambrian basement, some of which coincide with structures mapped at surface. A number of intrusions of probable Caledonian age have been recognized, including bodies beneath the Widmerpool Gulf and The Wash. Those beneath The Wash appear to lie in a discrete basement region which separates belts of more magnetic basement lying to the northwest and southeast.

Type
Articles
Information
Geological Magazine , Volume 130 , Issue 5 , September 1993 , pp. 593 - 604
Copyright
Copyright © Cambridge University Press 1993

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References

Allsop, J. M., Ambrose, K. & Elson, R. J. 1987. New data on the stratigraphy and geophysics in the area around Hollowell, Northamptonshire, provided by a coal exploration borehole. Proceedings of the Geologists Association 98, 157–70.CrossRefGoogle Scholar
Bott, M. H. P., Robinson, J. & Kohnstamm, M. A. 1978. Granite beneath Market Weighton, east Yorkshire. Journal of the Geological Society, London 135, 535–43.CrossRefGoogle Scholar
Busby, J. P. 1987. An interactive FORTRAN 77 program using GKS graphics for 2.5D modelling of gravity and magnetic data. Computers and Geosciences 13, 639–44.CrossRefGoogle Scholar
Chacksfield, B. C., De Vos, W., D'Hooge, L., Dusar, M., Lee, M. K., Poitevin, C., Royles, C. P. & Verniers, J. 1993. A new look at Belgian aeromagnetic and gravity data through image-based display and integrated modelling techniques. Geological Magazine 130, 583–91.CrossRefGoogle Scholar
Chadwick, R. A. 1985. Seismic reflection investigations into the stratigraphy and structural evolution of the Worcester Basin. Journal of the Geological Society, London 142, 187–202.CrossRefGoogle Scholar
Chadwick, R. A., Kenolty, N. & Whittaker, A. 1983. Crustal structure beneath southern England from deep seismic reflection profiles. Journal of the Geological Society, London 140, 893–911.CrossRefGoogle Scholar
Chadwick, R. A. & Smith, N. J. P. 1988. Evidence of negative structural inversion beneath central England from new seismic reflection data. Journal of the Geological Society, London 145, 519–22.Google Scholar
Chroston, P. K., Allsop, J. M. & Cornwell, J. D. 1987. New seismic refraction evidence on the origin of the Bouguer anomaly low near Hunstanton, Norfolk. Proceedings of the Yorkshire Geological Society 46, 311–19.CrossRefGoogle Scholar
Cook, A. H. & Thirlaway, H. I. S. 1955. The geological results of measurements of gravity in the Welsh Borders. Quarterly Journal of the Geological Society of London 111, 47–70.CrossRefGoogle Scholar
Cornwell, J. D. 1978. Geophysical surveys at the Withycombe Farm borehole. Bulletin of the Geological Survey of Great Britian 68, 33–42.Google Scholar
Cornwell, J. D. 1992. Geological significance of regional geophysical anomalies in the Worcester District. British Geological Survey Technical Report WK/92/17.Google Scholar
Cornwell, J. C., Royles, C. P. & Self, S. J. 1990. Regional geophysical anomalies in East Anglia: a preliminary geological assessment. British Geological Survey Technical Report WK/90/32.Google Scholar
Cornwell, J. D. & Walker, A. S. D. 1989. Regional Geophysics. In Metallogenic Models and Exploration Criteria for buried Carbonate-Hosted Ore Deposits – A Multidisciplinary Study in Eastern England (eds Plant, J. A. and Jones, D. G.), pp. 25–51. London: Institution of Mining and Metallurgy/British Geological Survey.Google Scholar
Ellis, P. F. & Kearey, P. 1984. An investigation of the Reading-Newbury magnetic anomaly. Journal of the Geological Society, London 141, 349–56.CrossRefGoogle Scholar
Evans, A. M. & Maroof, S. I. 1976. Basement controls on mineralisation in the British Isles. Mining Magazine 134, 401–11.Google Scholar
Evans, C. J., Kimbell, G. S. & Rollin, K. E. 1988. Hot dry rock potential in urban areas. Report in series: Investigation of the Geothermal Potential of the UK. Keyworth, Nottingham: British Geological Survey.Google Scholar
Foster, D., Holliday, D. W., Jones, C. M., Owens, B. & Welsh, A. 1989. The concealed Upper Palaeozoic rocks of Berkshire and South Oxfordshire. Proceedings of the Geological Association of London 100, 395–407.CrossRefGoogle Scholar
Fraser, A. J., Nash, D. F., Steele, R. P. & Ebdon, C. C. 1990. A regional assessment of the intra-Carboniferous play of Northern England. In Classic Petroleum Provinces (ed. Brooks, J.), pp. 417–40. Geological Society Special Publication no. 50.Google Scholar
Henkel, H. 1991. Petrophysical properties (density and magnetisation) of rocks from the northern part of the Baltic Shield. Tectonophysics 192, 1–19.CrossRefGoogle Scholar
Holliger, K. & Klemperer, S. L. 1991. Gravity and deep seismic reflection profiles across the North Sea rifts. In Tectonic evolution of the North Sea rifts (eds. Blundell, D. J. and Gibbs, A. D.), pp. 83–100. Oxford: Oxford University Press.Google Scholar
Institute of Geological Sciences. 1965. Aeromagnetic map of Great Britain. Sheet 2. Chessington, Surrey: Ordnance Survey.Google Scholar
Kearey, P. 1991. A deep basaltic source of the south-central England anomaly. Journal of the Geological Society, London 148, 775–80.Google Scholar
Le Bas, M. J., 1972. Caledonian igneous rocks beneath central and eastern England. Proceedings of the Yorkshire Geological Society 39, 71–86.Google Scholar
Lee, M. K., Pharaoh, T. C. & Green, C. A., 1991. Structural trends in the concealed basement of eastern England from images of regional potential field data. Annales de la Société Géologique de Belgique 114, 45–62.Google Scholar
Lee, M. K., Pharaoh, T. C. & Soper, N. J. 1990. Structural trends in central Britain from images of gravity and aeromagnetic fields. Journal of the Geological Society, London 147, 241–58.Google Scholar
Lee, M. K., Pharaoh, T. C., Williamson, J. P., Green, C. A. & De Vos, W. 1993. Evidence on the deep structure of the Anglo-Brabant Massif from gravity and magnetic data. Geological Magazine 130, 575–82.CrossRefGoogle Scholar
Leeder, M. R. & Hardman, M., 1990. Carboniferous geology of the Southern North Sea Basin and controls on hydrocarbon prospectivity. In Tectonic events responsible for Britain's oil and gas reserves (eds Hardman, R. F. P. and Brooks, J.), pp. 87–105. Special Publication of the Geological Society of London no. 55.Google Scholar
Merriman, R. J., Pharaoh, T. C., Woodcock, N. H. & Daly, P. 1993. The metamorphic history of the concealed Caledonides of eastern England and their foreland. Geological Magazine 130, 613–20.Google Scholar
Pedley, R. C. 1991. GRAVMAG User Manual: Interactive 2.5D gravity and magnetic modelling program. Keyworth, Nottingham: British Geological Survey.Google Scholar
Penn, I. E., Chadwick, R. A., Holloway, S., Roberts, G., Pharoah, T. C., Allsop, J. M., Hulbert, A. G. & Burns, I. M. 1987. Principal features of the hydrocarbon prospectivity of the Wessex-Channel Basin, UK. In Petroleum geology of North West Europe (eds. Brooks, J. and Glennie, K.), pp. 109–18. London: Graham & Trotman.Google Scholar
Pharaoh, T. C., Brewer, T. S. & Webb, P. C. 1993. Subduction-related magmatism of late Ordovician age in eastern England. Geological Magazine 130, 647–56.Google Scholar
Pharaoh, T. C. & Gibbons, W. In press. Precambrian. Special Report of the Geological Society of London 6 (revised).Google Scholar
Pharaoh, T. C., Merriman, R. J., Webb, P. C. & Beckinsale, R. D. 1987 a. The concealed Caledonides of eastern England: Preliminary results of a multidisciplinary study. Proceedings of the Yorkshire Geological Society 46, 355–69.CrossRefGoogle Scholar
Pharaoh, T. C., Webb, P. C., Thorpe, R. S. & Beckinsale, R. D. 1987 b. Geochemical evidence for the tectonic setting of late Proterozoic volcanic suites in the central UK. In Geochemistry and Mineralisation of Proterozoic Volcanic Suites (eds Pharaoh, T. C., Beckinsdale, R. D. and Rickard, D. T.), pp. 541–52. Special Publication of the Geological Society, London no. 33.Google Scholar
Poole, E. G. 1978. The stratigraphy of the Withycombe Farm borehole, near Banbury, Oxfordshire. Bulletin of the Geological Survey of Great Britain no. 68. 63 pp.Google Scholar
Rollin, K. E., 1980. Interpretation of the Widmerpool Gulf from gravity data. Institute of Geological Sciences, Applied Geophysics Unit Report no. 93.Google Scholar
Rushton, A. W. A. & Molyneux, S. G., 1990. The Withycombe Formation (Oxfordshire subcrop) is of early Cambrian age. Geological Magazine 11, 363.Google Scholar
Smalley, S. & Westbrook, G. K. 1982. Geophysical evidence concerning the southern boundary of the London Platform beneath the Hog's Back, Surrey. Journal of the Geological Society, London 139, 139–46.Google Scholar
Smith, N. J. P. 1987. The deep geology of central England: the prospectivity of the Palaeozoic rocks. In Petroleum geology of North West Europe (eds. Brooks, J. and Glennie, K.), pp. 217–24. London: Graham & Trotman.Google Scholar
Thorpe, R. S., Beckinsale, R. D., Patchett, P. J., Piper, A., Davies, G. R. & Evans, J. A. 1984. Crustal growth and late Precambrian–early Palaeozoic plate tectonic evolution of England and Wales. Journal of the Geological Society, London 141, 521–36.Google Scholar
Whittaker, A. (ed.). 1985. Atlas of onshore sedimentary basins in England and Wales: post-Carboniferous tectonics and stratigraphy. Glasgow: Blackie.Google Scholar