The BGS Lexicon of Named Rock Units — Result Details

Knock Head Grit Member

Computer Code: KNHG Preferred Map Code: KnHG
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Interbedded psammite, locally pebbly, semipelite and pelite in graded units. Finer-grained beds metamorphosed to slates, phyllites and mica-schists. Minor calc-silicate pods. Contains andalusite, cordierite and locally staurolite porphyroblasts.
Definition of Lower Boundary: Change from calcareous semipelite and psammite to non-calcareous psammite-dominated lithologies at top of Whitehills Grit Formation; commonly marked by change to locally coarsely gritty psammite.
Definition of Upper Boundary: Transition to graded units with greater proportion of semipelite. Psammites only rarely pebbly.
Thickness: c.0.5km; relatively little repetition by folding.
Geographical Limits: From Moray Firth coast [NJ 6514 6564-NJ 663 654], southwards to northern margin of Aberchrder Granite [NJ 630 530].
Parent Unit: Macduff Formation (MCD)
Previous Name(s): Knock Head Grit (-4132)
Uppermost Part Of Whitehills Group (-4133)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Coastal section from Craig Neen, Whitehills to east side of Knock Head (western end of Boyndie Bay). 
Reference(s):
Harris, A L, Haselock, P J, Kennedy, M J and Mendum, J R, 1994. The Dalradian Supergroup in Scotland, Shetland and Ireland. 33-53 in Gibbons, W E and Harris, A L (editors). A revised correlation of Precambrian rocks in the British Isles. Special Report of the Geological Society, London, No.22. 
Stephenson, D and Gould, D , 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey), 67-68. 
Stephenson, D, et al. 1993. Stratigraphy and correlation of the Dalradian rocks of the East Grampian Project area. British Geological Survey Technical Report WA/93/91. 
Read, H H, 1923. Geology of the country around Banff, Huntly and Turriff, Lower Banffshire and north-west Aberdeenshire. Memoir of the Geological Survey, Scotland Sheets 86 and 96 (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S096 S096