The BGS Lexicon of Named Rock Units — Result Details

Tarfside Psammite Formation

Computer Code: TPS Preferred Map Code: litho
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Psammite, much of it quartzitic, and calcareous psammite, with minor pelite and semipelite, passing up into mixed psammite and semipelite: beds of meta-limestone and calc-silicate rock throughout.
Definition of Lower Boundary: Top of Deeside Limestone Formation - change from dominant calc-silicate rock to dominant psammite.
Definition of Upper Boundary: Base of Glen Effock Schist Formation - change to semipelite with much psammite and pelite: marked by incoming of magnetic horizons within the semipelites.
Thickness: (i) Probably no more than 500m north of Mount Battock Granite (top not seen): (ii) 1250 - 2750m south of Mount Battock Granite; upper figure probably overestimate, due to tectonic thickening of Glen Turret Member.
Geographical Limits: (i) Deeside: North of Mount Battock Granite, south of Deeside Limestone Formation [NO 420 957 to 560 955] (ii) Tarfside: South of Mount Battock Granite, north of Glen Effock Schist Formation [NO 405 846 to 570 817]. (iii) Sheet 65E. Strip bounded to east by Water of Tanar Limestone Formation, to west by the Glen Effock Schist Formation [NO 415 952 to 370 800]. Southern boundary is lateral transition to Cald Burn Gneiss Formation.
Parent Unit: Tayvallich Subgroup (DBTV)
Previous Name(s): Glen Tanar Quartzite And Mica Schist Group (-2499)
Tarfside Group (-3731)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Sheet 65E (Ballater). Good section in Water of Lee and also in the Burn of Badrone [NO 3670 8145 to 3660 8200]. 
Type Area  Sheet 66W are those for component members Glen Tanar Quartzite and Glen Turret Psammite and Semipelite members: north of Mount Battock Granite. Good exposures in the banks of the Water of Tanar from 100m above to 50m below the Brig O' Ess. 
Type Area  (Sheet 66W) (i) South of Mount Battock Granite (Glen Tanar Quartzite Member). Part of Branny Burn Section. 
Type Area  (Sheet 66W) (ii) South of Mount Battock Granite. (Glen Turret Psammite and Semipelite Member). Burn of Turret Section from R. North Esk to granite contact. 
Reference(s):
Read, H H, 1928. The Highland Schists of Middle Deeside and Upper Glen Muick. Transactions of the Royal Society of Edinburgh, Vol.55, p.755-772. 
Smith, C G, Goodman, S and Robertson S. 2003. Geology of the Ballater district. Memoir of the British Geological Survey, Sheet 65E (Scotland). 
Harte, B, 1979. The Tarfside succession and the structure and stratigraphy of the eastern Scottish Dalradian rocks. "In" Harris, A L, Holland, C H and Leake, B E. Geological Society of London Special Publication No.8, p.221-228. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S065 S066 S066