The BGS Lexicon of Named Rock Units — Result Details

Lusa Limestone Member

Computer Code: LUSA Preferred Map Code: notEntered
Status Code: Full
Age range: Hettangian Age (JH) — Hettangian Age (JH)
Lithological Description: Alternating fossiliferous wackestones, packstones and micritic limestones with interbedded calcarenites.
Definition of Lower Boundary: This formation marks the local base of the Jurassic on Skye and generally unconformably overlies Neoproterozoic ("Torridonian") strata.
Definition of Upper Boundary: The unit is a member within the Breakish Formation and the upper boundary is marked by a transition from carbonate facies of the unit to overlying massive sandstone.
Thickness: 25 to 30m
Geographical Limits: Typically in the northern part of Skye, east of Breakish, but part of the Breakish Formation, which is found within the Sea of the Hebrides Basin.
Parent Unit: Breakish Formation (BRKH)
Previous Name(s): (Unnamed Limestone) (-3543)
Broadford Beds (Part) (-1053)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  ObLusa, Breakish, Isle of Skye. Beds 2 to 16 as shown on Fig.7 of Morton and Hudson (1995). Morton, N, and Hudson, J D. 1995. 
Reference(s):
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. 
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.) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable