The BGS Lexicon of Named Rock Units — Result Details

Garron Point Tremolitic Flag Member

Computer Code: GART Preferred Map Code: GarT
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Semipelite, flaggy, calcareous and minor micaceous psammite, green with tremolitic amphibole porphyroblasts prominent in most exposures. Upper part locally contains thin, lenticular bands of metalimestone.
Definition of Lower Boundary: Transition from dominantly bluish and purplish grey calcareous flaggy semipelite to dominantly greenish grey tremolitic lithologies.
Definition of Upper Boundary: Sharp change from tremolitic flags to interbedded graphitic pelite, semipelite and metalimestone of Mortlach Graphitic Schist Member.
Thickness: c.250 to 300m on coast section; not measurable inland.
Geographical Limits: From coast at Garron Point [NJ 5525 6700-5550 6700], as far inland as fault at [NJ 532 633], south of which it is covered by Devonian sedimentary rocks.
Parent Unit: Cairnfield Calcareous Flag Formation (CCFL)
Previous Name(s): Garron Point Actinolitic Schists (-275)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  On coast from west to east side of Garron 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. 
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), 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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S096