The BGS Lexicon of Named Rock Units — Result Details
Crathie Point Calc-Silicate Member
Computer Code: | CRPT | Preferred Map Code: | CrPt |
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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) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Section | On coast at Crathie Point. | ||
Reference(s): | |||
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. | |||
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). | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
S096 |