The BGS Lexicon of Named Rock Units — Result Details

Gala Unit 8

Computer Code: GAL8 Preferred Map Code: GALA8
Status Code: Full
Age range: Aeronian Age (SA) — Telychian Age (ST)
Lithological Description: Graded beds that may include wacke sandstone, siltstone and mudstone in variable proportion, interpreted as turbidites.
Definition of Lower Boundary: Southern faulted boundary: Mochrum Fault (Rhins of Galloway and Wigtown Peninsula). Stratigraphical lower boundary with underlying Moffat Shale Group (of Ordovician to Silurian age up to sedwickii to possible turriculatus Biozones).
Definition of Upper Boundary: Northern faulted boundary: southernmost splay of Port Logan Fault (Rhins of Galloway); Cambret Fault (Kirkcowan and Wigtown).
Thickness: c. 800m of near vertical strata (Rhins)
Geographical Limits: Mapped from Port Logan Bay on the Rhins of Galloway (Sheet 1/3) to Wigtown (Sheet 4E). Possible correlation with Central Belt turbidites of Llandovery age in the Ards Peninsula, Northern Ireland.
Parent Unit: Gala Group (GALA)
Previous Name(s): Gala Group (GALA)
Queensberry Grits (-1552)
Intermediate And Garnetiferous Greywacke Groups (-273)
Alternative Name(s): Port Logan Formation Of The Rhins Of Galloway (Sheet 1/3)
Stratotypes:
Reference Section  Coastal section north of Clanyard Bay, 2 km. south of Port Logan, Rhins of Galloway (Sheet 1/3). Stone, 1995. 
Reference(s):
Lapworth, C, 1871. On the Lower Silurian rocks in the neighbourhood of Galashiels. Transactions of the Edinburgh Geological Society, 2, 46 - 58. 
Walton, E K. 1955. Silurian greywackes in Peeblesshire. Proceedings of the Royal Society of Edinburgh, B65, 327-357. 
Stone, P, 1995. Geology of the Rhins of Galloway district. Memoir of the British Geological Survey, Sheets 1 & 3 (Scotland). 
Barnes, R P, Anderson, T B and McCurry, J A . 1987. Along-strike variation in the stratigraphical and structural profile of the Southern Uplands Central Belt in Galloway and Longford Down. Journal of the Geological Society, 144, 807 - 816. 
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:
S001 S003 S004 S004 N29