The BGS Lexicon of Named Rock Units — Result Details

Glen Turret Psammite And Semipelite Member

Computer Code: GTP Preferred Map Code: SYMB
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Psammite, mostly feldspathic and slightly micaceous, interbedded with and transitional to muscovite-biotite-semipelite with low magnetic susceptibility: contains beds of calc-silicate rock and rare limestone.
Definition of Lower Boundary: Change from more massive and quartzose psammite at top of Glen Tanar Quartzite Member; this change is typically gradational.
Definition of Upper Boundary: Incoming of beds of dark biotitic semipelite with high magnetic susceptibility at base of Glen Effock Schist Formation.
Thickness: Apparently 1500m thick in Glen Turret and vicinity, but this is probably inflated by tectonic thickening. Thins rapidly south-westwards and is absent on Auld Craig (NO 455 782).
Geographical Limits: South of Mount Battock Granite and east of Loch Lee, forming one strip around Lower Glen Mark (NO 420 800 to NO 415 850) and another around Glen Turret (NO 530 780 to NO 543 834).
Parent Unit: Tarfside Psammite Formation (TPS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Stream section in Burn of Turret from just upstream of Millden Lodge to granite contact at NO 550 817 and in Black Burn from its confluence with White Burn to NO 542 827. 
Smith, C G, Goodman, S and Robertson S. 2003. Geology of the Ballater district. Memoir of the British Geological Survey, Sheet 65E (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S065 S066