The BGS Lexicon of Named Rock Units — Result Details

Sannox Siltstone Formation

Computer Code: SXS Preferred Map Code: SXS
Status Code: Pending Upgrade
Age range: Early Devonian Epoch (DL) — Early Devonian Epoch (DL)
Lithological Description: Red-brown siltstones and silty mudstones, with beds of sandstone and quartzite conglomerate.
Definition of Lower Boundary: The top of the Glen Sannox Conglomerate Member of the Am Binnein Sandstone Formation.
Definition of Upper Boundary: The base of the sandstone, unnamed on Arran sheet GVS, but referred to as the North Sannox Sandstones by Morton (1979)(Fig.1), and correlatable with the Teith Sandstone Formation.
Thickness: About 350 m thick.
Geographical Limits: The Isle of Arran.
Parent Unit: Strathmore Group (SEG)
Previous Name(s): Allt Na H'Ath Siltstones (-1215)
Sannox Siltstones (*43)
Alternative Name(s): Cromlox Mudstone Formation
Stratotypes:
Partial Type Section  Glen Sannox, faulted at top. 
Reference(s):
Browne, M A E, Smith, R A and Aitken, A M. 2001. A lithostratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen. Version 3. British Geological Survey Research Report RR/01/04. 
Friend, P F, Harland, W B and Hudson, J D, 1963. The Old Red Sandstone and the Highland Boundary in Arran, Scotland. Transactions of the Edinburgh Geological Society, Vol.19, 363-425. 
Morton, D J, 1979. Palaeogeographical evolution of the Lower Old Red Sandstone Basin in the western Midland Valley. Scottish Journal of Geology, Vol.15, 97-116, Fig.1 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S338 S013