The BGS Lexicon of Named Rock Units — Result Details

Kildonan Psammite Formation

Computer Code: KILD Preferred Map Code: symb
Status Code: Full
Age range: Tonian Period (AT) — Tonian Period (AT)
Lithological Description: Psammite, siliceous to micaceous, medium-grained. Psammite shows locally tabular and trough cross-bedding. Subordinate layers of quartz and schistose semipelite. Locally very thin (<5 cm) schistose para-amphibolite.
Definition of Lower Boundary: Not exposed. Base is interpreted to be cut by the Skinsdale Thrust.
Definition of Upper Boundary: Conformable overlain by the Suisgill Semipelite Formation (SUIS), with a gradational (100 m) boundary marked by increasing semipelitic layers. Locally overlain by the Scaraben Quartzite Formation (SCAB), but not exposed.
Thickness: none recorded or not applicable
Geographical Limits: Northern Highlands: East Sutherland and Caithness. Restricted to the Skinsdale Nappe.
Parent Unit: Loch Eil Group (LEIL)
Previous Name(s): Kildonan Psammite [Obsolete Name and Code: Use KILD] (-2874)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Reference sections at Suisgill Burn [NC 915 271]; Torrish Burn [NC 971 199]. 
Reference(s):
Strachan, R A, 1989. The metamorphic rocks of the Scaraben area, East Sutherland and Caithness. Scottish Journal of Geology, Vol.24, 1-13. 
Krabbendam, M. 2021. A stratigraphic framework for the early Neoproterozoic successions of the Northern Highlands of Scotland. UK Stratigraphic Framework Series. British Geological Survey Open Report, OR/21/072. 86pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S103 S103 S109 S109