The BGS Lexicon of Named Rock Units — Result Details
Crathie Point Calc-Silicate Member
| Computer Code: | CRPT | Preferred Map Code: | CrPt |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ) | ||
| Lithological Description: | Thin-bedded flaggy calc-silicate, calcareous semipelite and impure metacarbonate rock, with beds of metalimestone; bands of distinctive schistose garnet-muscovite-biotite semipelite in upper part. Calcareous psammite beds sparse but more abundant near top. | ||
| Definition of Lower Boundary: | Base of lowest limestone bed in sequence of flaggy semipelites and psammites of Cairnfield Calcareous Flag Formation. | ||
| Definition of Upper Boundary: | Transitional decrease in frequency of limestone beds and increase in proportion of calc-psammites relative to calc-semipelites. | ||
| Thickness: | c.200 to 250m on coast section, but locally tightly folded; not measurable inland. | ||
| Geographical Limits: | From coast at Crathie Point [NJ 5475 6725 - 5495 6715], as far inland as Broom [NJ 543 662], south of which it cannot be distinguished from the rest of the Cairnfield Calcareous Flag Formation. | ||
| Parent Unit: | Cairnfield Calcareous Flag Formation (CCFL) | ||
| Previous Name(s): | Middle Portion of Crathie Point Calcareous Group [Obsolete Name and Code: Use CRPT]
(-3333)
Crathie Point Calcareous Flag Member [Obsolete Name and Code: Use CRPT] (-2118) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | On coast at Crathie Point. | ||
| 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 | |||