The BGS Lexicon of Named Rock Units — Result Details
Castle Point Pelite Formation
| Computer Code: | CAPT | Preferred Map Code: | CaPt |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ) | ||
| Lithological Description: | Pelite, locally graphitic at base (John Legg's Well Graphitic Schist Member) and in central-upper part at coast, but less graphitic with rare metalimestone bands inland, passing upward into semipelite, flaggy. Prominent staurolite at Castle Point, and locally kyanite-bearing. | ||
| Definition of Lower Boundary: | Rapid transition from psammite and quartzite, through thin semipelite to graphitic pelite (John Legg's Well Graphitic Schist Member). | ||
| Definition of Upper Boundary: | Transition to thin banded metalimestones and calcareous semipelites (Sandy Pots Limestone Member) at base of Portsoy Limestone Formation. | ||
| Thickness: | c.300 to 400m at coast, though there is duplication by folding and thrusting. Inland as far as the south end of Fordyce Hill, only about 100m is present between a major ductile shear zone and the Portsoy basic intrusion. East of Knock Hill [near NJ 550 550] the poorly exposed pelitic rocks cannot be differentiated from those of the Portsoy Limestone Formation. | ||
| Geographical Limits: | Coast section from John Legg's Well to Sandy Pots [NJ 580 665 to 584 665]; extends southwards as far as Clovenstone [NJ 548 517], together with isolated inliers and xenoliths in Portsoy basic intrusion. | ||
| Parent Unit: | Easdale Subgroup (DBED) | ||
| Previous Name(s): | Lower Part Of Portsoy Group [Obsolete Name and Code: Use CAPT]
(-4514)
Portsoy Group [Obsolete Name And Code: See CAPT And PTSL] (DBPB) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Coastal section from John Legg's Well to Sandy Pots. | ||
| 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, 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). | |||
| Stephenson, D and Gould, D. 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey.) | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S086 S096 | |||