The BGS Lexicon of Named Rock Units — Result Details

Upper Ostrea Member

Computer Code: UOST Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Bathonian Age (JN) — Callovian Age (JC)
Lithological Description: This Member records the major Callovian transgression in Europe. Mudstone and siltstones predominate with a low-diversity bivalve fauna. "Ostrea" is anomalous as they are not the dominant fossils. Unit is present in the Staffin Bay area of northern Skye, but absent farther south.
Definition of Lower Boundary: Sharp base, dark clay with plant fragments, thin shell beds of Neomiodon and Isognomon, mudstones and shell-rich beds - indicative of a gentle, lagoonal transgression.
Definition of Upper Boundary: Gradationally overlain by sandstone of the 'Belemnite Sands'.
Thickness: 11m+
Geographical Limits: Sea of the Hebrides Basin.
Parent Unit: Staffin Bay Formation (STBA)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Staffin Bay, Trotternish, northern Skye. Morton and Hudson, 1995. 
Reference(s):
Hudson, J D, and Trewin, N H. 2002. Jurassic. 323-350 in The geology of Scotland. Trewin, N H (editor). (London: Geological Society of London.) 
Cox, B M, Page, K N and Morton, N, 2002. The Middle Jurassic stratigraphy of Scotland. In Cox, B M and Sumbler, M G (editors), British Middle Jurassic Stratigraphy. Geological Conservation Review Series, Vol.26. (Peterborough: Joint Nature Conservation Committee/Chapman and Hall.) 
Morton, N and Hudson, J D, 1995. Field Guide to the Jurassic of the Isles of Raasay and Skye, Inner Hebrides, north-west Scotland. In: Taylor, P D (editor), Field Geology of the British Jurassic. Geological Society of London, 209-280. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S080 S090