The BGS Lexicon of Named Rock Units — Result Details
Macduff Formation
| Computer Code: | MCD | Preferred Map Code: | Mcd |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ) | ||
| Lithological Description: | Metagreywacke: interbedded psammite and semipelite with subsidiary pelite. Contains major units of pebbly psammite, particularly in basal part (Knock Head Grit Member). Metamorphosed to slates, phyllites and mica-schists. Contains Boulder Bed at Macduff (glaciomarine diamicton). Minor calc-silicate pods. Contains andalusite, cordierite and locally staurolite porphyroblasts. | ||
| Definition of Lower Boundary: | Change from calcareous semipelite to non-calcareous lithologies at top of Whitehills Grit Formation; commonly marked by change to locally coarsely gritty psammite of Knock Head Grit Member. | ||
| Definition of Upper Boundary: | Not seen - highest beds are in centre of Turriff Syncline. | ||
| Thickness: | Up to 5.5km, but could be less, as there is repetition by folding. | ||
| Geographical Limits: | From Moray Firth coast [NJ 6514 6564-NJ 776 643], southwards to northern margin of Insch intrusion [NJ 650 325-NJ 725 305]. | ||
| Parent Unit: | Southern Highland Group (SOHI) | ||
| Previous Name(s): | [Obsolete Code: Use MCD]
(*259)
Boyndie Bay Formation [Obsolete Name And Code: See MCD] (DCBD) Macduff Slate [Obsolete Name And Code: Use MCD] (DCMS) Boyndie Bay Group [Obsolete Name and Code: Use MCD, DCBD] (-203) Macduff Slates [Obsolete Name and Code: Use MCD] (-1685) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Coastal section from Craig Neen, Whitehills to Grip of Twinely (centre of Turriff Syncline). | ||
| 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. | |||
| 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). | |||
| 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. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S096 S096 S086 S086 S087 | |||