Area: 87.29 hectares.
A Geological Conservation Review (GCR) site. The northern and southern boundaries lie between Steeple Point to Marsland Mouth SSSI and Bude Coast SSSI respectively.
Description and Reasons for Notification:
The 3.2 kilometer long coastal section between Duckpool and Furzey Cove represent part of the type area for the Bude Formation, the youngest division of the Upper Carboniferous succession in Devon and Cornwall. The cliffs and foreshore expose a sequence of approximately 1,620 metres of alternating shales, mudstones and siltstone with interbedded sandstones. The sandstones are rich in sedimentary structures including sand volcanoes and hummocky cross-stratification, the latter probably generated by storm waves in shallow water conditions.
Biostratigraphical control on the age of the Bude Formation is provided by thick shale horizons with marine faunas, in particular ammonoids, including the Hartland Quay Shale (topmost Crackington Formation with Gastrioceras amaliae. Langsettian), the Long Peak Shale (with ammonoid and fish remains, probably Langsettian), Tom’s Cove Shale (with coelocanthid Rhabdoderma elegans), the Sandy Mouth Shale (with Anthracoceroides cornubiensis, Langsettian) and the Warren Gutter Shale (with Donetzoceras aegiranum and Gastrioceras depressum of early Bolsonian age). The Saturday’s Pit Shale is palaeontologically important as it yields fragmentary fish remains including Cornuboniscus budensis and Acanthodes wardi along with Elonicthys aitkeni and the crustacean Crangopsis huxleyi. Several levels in this succession show xiphosaurid trails, again indicating a shallow water environment of deposition for much of the formation.
The combination of being a key part of the Bude Formation stratotype, exhibiting excellent sedimentary features and yielding palaeontologically important faunas for good biostratigraphical control, makes the Duckpool to Furzey Cove section of very high national importance for the study of Upper Carboniferous rocks in Britain.