The BGS Lexicon of Named Rock Units — Result Details

Craigievar Formation

Computer Code: CRR Preferred Map Code: SYMB
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Interlayered psammite, semipelite and pelite, with semipelite dominant. Contains beds of calc-silicate rock, especially in the vicinity of Towie (NJ 440 127).
Definition of Lower Boundary: Not seen: a major antiform, now largely obscured by the Tomnaverie, Coull and Lumphanan intrusions, causes the formation to be flanked by younger rocks both to the north and to the south.
Definition of Upper Boundary: Change to the more uniform semipelitic lithology, but with mappable units of gritty psammite, which characterises the Suie Hill Formation. Upper contact to the west of the Rhynie Devonian inlier occurs at the base of a magnetic pelite unit (NJ 394 246 to NJ 459 215). To the east of the Rhynie Devonian it runs through poorly exposed ground (NJ 471 165 to NJ 622 184), where it abuts the Bennachie Granite. The fault-displaced contact reappears at NJ 630 134 to NJ 650 134.
Thickness: Several kilometres, but not measurable due to the intense folding and migmatisation over most of the outcrop.
Geographical Limits: Occupies most of the central part of Sheet 76W (Alford) extending into the eastern part of Sheet 75E (Glenbuchat) and the western part of Sheet 76E (Inverurie).
Parent Unit: Tayvallich Subgroup (DBTV)
Previous Name(s): Donside Gneisses (-168)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  For Sheet 76W. Hill to the west of Oldtown of Carnaveron and ridge extending to Carnaveron Hill (chosen for relative lack of granite veins and slight degree of migmatisation). 
Type Area  For Sheet 76E. Hill slopes of Pittendamph and White Hill above forestry plantation. 
Reference(s):
Harris, A L and Pitcher, W S, 1975. The Dalradian Supergroup. "In" Harris, A L, Shackleton, R M, Watson, J, Downie, C, Harland, W B and Moorbath, S. A correlation of the Precambrian rocks in the British Isles. Geological Society Special Report, No.6. p.52-75. Scottish Academic Press, Edinburgh. 
Gould, D. 1997. Geology of the area around Alford and Inverurie. Memoir of the British Geological Survey, Sheets 76E and 76W (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S076 S075 S076