The BGS Lexicon of Named Rock Units — Result Details

Clava Shelly Formation

Computer Code: CLSH Preferred Map Code: ClSh
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Diamicton, olive-grey, very stiff, fissile, with sparse shell material and silty sand. See also details of the Dalroy Sand (DROY), Clava Lodge Clay (CLOCL) and Culdoich Till (CUTI) members.
Definition of Lower Boundary: Unconformable, glacitectonic boundary of the Clava Lodge Clay Member of the Clava Shelly Formation with the Drummore Gravel Formation below.
Definition of Upper Boundary: Unconformable, glacitectonic boundary with Finglack Till Formation above.
Thickness: 11m at type section
Geographical Limits: Sheet NH74SE.
Parent Unit: Banffshire Coast and Caithness Glacigenic Subgroup (BCD)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Section in former clay pit by Cassie Burn; boreholes (1) and (3) of Horne et al, (1894). Section NH74SE E5 'standard' map. Lectostratotype (Horne et al, 1894;'Main Pit'), type section and borehole information. Established informally in Merritt (1990). 
Reference Section  River cliff section of Cassie Burn. Section NH74SE E9 on 'standard' map. Lectostratotype (Peacock, 1975). Dalroy (formerly Clava) Sand and Culdoich (formerly Clava) Shelly Till members only. 
Reference(s):
Peacock, J D, 1975. Depositional environment of glacial deposits at Clava, north-east Scotland. Bulletin of the Geological Survey of Great Britain, No.49. 31-37. 
Fletcher, T P et al. 1996. Geology of the Fortrose and eastern Inverness district. Memoir of the British Geological Survey, Sheet 84W (Scotland). 
Merritt, J W 1992. The high-level marine shell-bearing deposits of Clava, Inverness-shire, and their origin as glacial rafts. Quaternary Science Reviews, Vol.11, 759-777. 
Merritt, J W, 1990. The lithostratigraphy at Clava, Inverness-shire and a new model for the origin of its shell-bearing deposits as glacially-transported allochthons. "In" Auton, C A, Firth, C R and Merritt, J W. (Editors). Beauly to Nairn: Field Guide. Quaternary Research Association, Cambridge. 
Horne, J and others, 1894. The character of the high-level shell-bearing deposits at Clava, Chapelhall and other localities. Report of the British Association for the Advancement of Science for 1883, p.483-514. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S084