The BGS Lexicon of Named Rock Units — Result Details

Glendouran Breccia Formation

Computer Code: GDN Preferred Map Code: notEntered
Status Code: Full
Age range: Cisuralian Epoch (PLC) — Cisuralian Epoch (PLC)
Lithological Description: Mainly poorly sorted breccio-conglomerates containing clasts mainly of greywacke sandstone and siltstone. Some pebbly and gravelly sandstone interbeds.
Definition of Lower Boundary: Unconformity at the base of the formation overlying the Ordovician Kirkcolm Formation in Holmhead Burn [NS 8820 2082].
Definition of Upper Boundary: Faulted off and not exposed, but lies towards the northeast in this local basin.
Thickness: c.700m
Geographical Limits: Small outlier, c.2-4km southsouthwest of Crawfordjohn, south Lanarkshire.
Parent Unit: Appleby Group (APY)
Previous Name(s): Snar Water Permian Breccia (-2821)
Snar Valley Breccia (-4672)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Section in Holmhead Burn from unconformity at its base to the uppermost beds exposed in this burn. 
Reference(s):
Peach, B N and Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoir of the Geological Survey of the United Kingdom. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S015