The BGS Lexicon of Named Rock Units — Result Details
Ardmillan Group
Computer Code: | AMN | Preferred Map Code: | notEntered |
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Status Code: | Full | ||
Age range: | Caradoc Series (O4) — Ashgill Series (OA) | ||
Lithological Description: | Turbiditic sandstone, siltstone and mudstone with conglomerate at its base. Lateral impersistence and occurrence of similar lithologies at different horizons cause difficulties with stratigraphy. | ||
Definition of Lower Boundary: | Drawn at the base of the Ballatchie Formation where blue grey nodular mudstone,siltstone,fine-grained sandstone and conglomerate rest conformably upon boulder conglomerate with matrix supported clasts of basalt, dolerite and gabbro of the Benan Conglomerate Formation. | ||
Definition of Upper Boundary: | Overlain unconformably by the Silurian Mulloch Hill Conglomerate Formation. | ||
Thickness: | c.2000m. | ||
Geographical Limits: | The Girvan area from Girvan south to Glen App. | ||
Parent Unit: | Not Applicable (-) | ||
Previous Name(s): | Ardmillan Series [Obsolete Name and Code: Use AMN]
(-4429)
Ardmillan Group (Upper Part) [Obsolete Name And Code: See AMN] (AMNA) Ardmillan Group (Lower Part) [Obsolete Name And Code: See AMN] (AMNC) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Area | Girvan. | ||
Reference(s): | |||
Williams, A, 1962. The Barr and Lower Ardmillan Series (Caradoc) of the Girvan district, southwest Ayrshire, with descriptions of the Brachiopoda. Memoir of the Geological Society of London, No.3. | |||
Lapworth, C, 1882. The Girvan Succession. Quarterly Journal of the Geological Society of London, Vol. 38, 537-666. | |||
Fortey, R A, Harper, D A T, Ingham, J K, Owen, A W, Parkes, M A, Rushton, A W A and Woodcock, N H. 2000. A revised correlation of Ordovician rocks in the British Isles. Geological Society Special Report, No.24. | |||
Ingham, J K, 1978. Geology of a continental margin 2: Middle and late Ordovician transgression, Girvan. "In" Bones, D R and Leake, B E. Crustal Evolution in North Western Britain and Adjacent Regions. Geological Journal Special Issue, No.10. p.163-176. | |||
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: | |||
none recorded or not applicable |