The BGS Lexicon of Named Rock Units — Result Details
Gala Unit 7
Computer Code: | GAL7 | Preferred Map Code: | GALA7 |
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Status Code: | Full | ||
Age range: | Aeronian Age (SA) — Aeronian Age (SA) | ||
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: Port Logan Fault (Rhins of Galloway); Cambret Fault (Wigtown Peninsula); Laurieston Fault east of Wigtown Bay. Stratigraphical lower boundary with underlying Moffat Shale Group (of Ordovician to Silurian age up to sedwickii - halli Biozones). | ||
Definition of Upper Boundary: | Northern faulted boundary southernmost splay of Drumbreddan Fault (Rhins of Galloway); Pibble Fault (Kirkcowan and Wigtown); Garheugh Fault (to the north-east). | ||
Thickness: | c. 1850m of near vertical strata | ||
Geographical Limits: | Mapped from Port Logan Bay on the Rhins of Galloway (Sheet 1/3) to Peebleshire (Sheet24E). 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)
Intermediate and Garnetiferous Greywacke Groups [Obsolete Name and Code: Use GAL8, GAL7] (-273) Queensberry Grits [Obsolete Name and Code: Use GDE, GALA, GAL1, GAL2, GAL3, GAL4, GAL5, GAL6, GAL7, GAL8] (-1552) Gala Group (GALA) |
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Alternative Name(s): | Mull of Logan Formation |
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Stratotypes: | |||
Reference Section | Referred to four informal members, the Cairnie Finnart, the Daw Point, Duniehinnie and Chair members; coastal section north of Port Logan Bay, 8.5 km SSW of Sandhead, Rhins of Galloway, Sheet 1/3. Stone, 1995. | ||
Reference Section | Discontinuous exposure of the lower part of Gala 7 from the south-east side of Skeoch Hill to the summit of Bishop Forest Hill, Shawhead, 10 km west of Dumfries. | ||
Reference(s): | |||
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. | |||
McMillan, A A. 2002. Geology of the New Galloway and Thornhill District. 2002. Memoir of the British Geological Survey. Sheets 9W and 9E (Scotland). | |||
Peach, B N and Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoir of the Geological Survey of the United Kingdom. | |||
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. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
S001 S003 S004 S004 S005 S009 S009 S016 S024 N29 S015 |