Quaternary exposures in Whitsand Bay, south-east Cornwall: Downderry and Wiggle Cliff
Cenozoic, clastic sediments, clay, coastal environments
The extensive Quaternary deposits, exposed in coastal sections in Whitsand Bay, South East Cornwall have received little attention in the recent literature. A thick sequence of raised littoral and possibly aeolian sands capped by a veneer of soliflucted head is described from the east of the Bay between Wiggle Cliff and Polhawn Cove, near Rame Head. Here, the great extent of unconsolidated in situ sands above a relict abrasion platform is considered to represent a transition from intertidal littoral to back-beach aeolian sediments associated with sea-level regression, probably during the late Ipswichian / early Devensian. Upper sand deposition is considered likely to have been penecontemporaneous with early solifluction. Further west at Downderry, relict littoral sands and gravels, now below the modern beach, occur beneath a stony clay unit. This clay is topped by an unusual stratified head sequence occurring beneath the more typical Main and Upper Head units. Clay horizons, interbedded with head, coarsen towards the top of the stratified sequence where they become dominantly loessic. The Upper Head, both here and at Wiggle Cliff, is characterised by the sporadic occurrence of small well-rounded local and exotic clasts apparently absent from the main soliflucted head. Both sites warrant further investigation, the aeolian sands and loessic horizons especially lending themselves to luminescence dating and so constraining further early Devensian sea-level fall and the onset of periglaciation in southwest Britain.
Furze, M. F. A. (1999). Quaternary exposures in Whitsand Bay, south-east Cornwall: Downderry and Wiggle Cliff. The Proceedings of the Ussher Society, 9, 379–383. http://www.ussher.org.uk/journal/90s/1999/documents/Furze_1999.pdf
Presented January 1999 at the Annual Conference of the Ussher Society, England.
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