Ludham Borehole

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Ludham waterworks, Catfield, Norfolk, 2012. The Ludham Borehole was located on this site.

The Ludham Borehole was a geological research borehole drilled in 1959 near

Formations, and for these formations to be thus correlated with strata of equivalent age in the North Sea
basin and north-west Europe.

History of investigation

Brian Funnell recovering core samples at the Ludham Borehole site, 1959. Image with kind permission Prof R.G. West.

In 1950 a pilot borehole was put down for exploratory water supply purposes at the

Marine Isotope Stages 97 to 96.[6]

Stratigraphy

The borehole log has been given by West (1962).[7] It was considered that the sedimentary sequence between – 7.6 and –49.7 m depth (grey sands, silts and clays) clearly belonged to the Crag Group. The sequence above this (brown sands with yellow clay seams and ferruginous material) was considered to resemble the uppermost division of Norwich Crag as described by Woodward (1881),[8]: 31  attributed to the Bure Valley Beds (now referred to the Wroxham Crag Formation. The geology at this location has been mapped by the British Geological Survey as glacial deposits of the Corton Formation overlying Crag Group (undifferentiated).[9]

Fauna and flora

Molluscs

Work by Norton (1967) investigated the molluscan fossils from the Ludham Borehole. A sequence of six biostratigraphic assemblage zones was identified, and the results correlated with palaeontological research at this and other sites.[10] It was noted by Norton (1977) that the molluscan fauna gave no indication of the clearly cyclical temperature changes evident from pollen and foraminiferal fossils in the Ludham sequence, and hence it was unreliable for palaeoclimatic interpretation.[11]: 50 

Plants

A sequence of pollen assemblage zones was identified by West (1962), which permitted the designation of five

Menapian.[7] The unnamed stage was later tentatively correlated with the Pastonian.[12]: 117  Further work was later conducted on Ludham pollen samples, yielding evidence for input by British rivers into the Crag sedimentary sequence in the southern North Sea basin.[13]

Dinoflagellates

Dinoflagellate assemblages were analysed by Wall & Dale (1968), and were found to correspond with five facies associations in the sequence identified by West (1962).[14] More detailed work was later conducted by Head (1996), permitting the identification of over 29 species.[3]

Foraminifers

A sequence of seven foraminiferal assemblage zones were identified by Funnell (1961) on the basis of research into the Ludham Pilot Boring. Those from the lower part of the sequence were correlated with the Red Crag Formation and from the upper part with the Norwich Crag Formation. The uppermost zone (7) had an arctic-type fauna correlated with the Weybourne Crag[1] (now referred to the Wroxham Crag Formation).

See also

References

  1. ^ a b Funnell, BM (1961). The Palaeogene and early Pleistocene of Norfolk. Transactions of the Norfolk and Norwich Naturalists’ Society, vol.19, pt.6.
  2. ^ West, RG (2000). A recollection from 50 years of Quaternary research in East Anglia. In: Dixon, RG (ed). The Geological Society of Norfolk. 50th Anniversary Volume. Geological Society of Norfolk, December 2000.
  3. ^ a b Head, MJ (1996). Late Cenozoic dinoflagellates from the Royal Society borehole at Ludham, Norfolk, eastern England. Journal of Paleontology, vol.70, no.4, pp.543-570.
  4. ^ Arthurton, RS, Booth, SJ, Morigi, AN, Abbott, MAW & Wood, CJ (1994). Geology of the country around Great Yarmouth. Memoir for 1:50,000 Geological Sheet 162. British Geological Survey, HMSO, London.
  5. ISBN 0 19 854414 6
    .: 260 
  6. ^ Meijer, T, Cleveringa, P, Munsterman, DK & Verreussel, CH (2006). The Early Pleistocene Praetiglian and Ludhamian pollen stages in the North Sea Basin and their relationship to the marine isotope record. Journal of Quaternary Science vol.21.3.
  7. ^ a b West, RG (1962). Vegetational history of the Early Pleistocene of the Royal Society Borehole at Ludham, Norfolk. Proceedings of the Royal Society of London, Series B, vol.155, pp.437-453.
  8. ^ Woodward, HB (1881). The Geology of the Country around Norwich. Memoirs of the Geological Survey of the United Kingdom.
  9. ^ British Geological Survey (1999). Mundesley and North Walsham. England and Wales Sheets 132 and 148. Solid and Drift Geology. 1:50,000. British Geological Survey, Keyworth, Nottingham.
  10. ^ Norton, PEP (1967). Marine Molluscan Assemblages in the Early Pleistocene of Sidestrand, Bramerton and the Royal Society Borehole at Ludham, Norfolk. Philosophic Transactions of the Royal Society of London, Series B, vol.253, no.784.
  11. ^ Norton, PEP (1977). Marine Mollusca in the East Anglian pre-glacial Pleistocene. In: Shotton, FW (ed). British Quaternary Studies - Recent Advances. Clarendon Press, Oxford, 1977.
  12. ISBN 0521219620
    .
  13. ^ Riding, JB, Moorlock, SP, Jeffrey, DH & Hamblin, RJO (1997). Reworked and indigenous palynomorphs from the Norwich Crag Formation (Pleistocene) of eastern Suffolk: implications for provenance, palaeogeography and climate. Proceedings of the Geologists’ Association, vol. 108, pt.1.
  14. ^ Wall, D & Dale, B (1968). Early Pleistocene dinoflagellates from the Royal Society borehole at Ludham Norfolk. New Phytologist, vol.67, pp.315-326.

Further reading

External links
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