The BGS Lexicon of Named Rock Units — Result Details
Lanark Group
| Computer Code: | LNK | Preferred Map Code: | LNK |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Silurian Period (S) — Early Devonian Epoch (DL) | ||
| Lithological Description: | Mainly terrestrial red-bed sequence of sandstones and conglomerates with intercalated calc-alkaline volcanic extrusive rocks. | ||
| Definition of Lower Boundary: | Unconformity with the Wenlock - (probably) Ludlow inliers of the southern Midland Valley (or the equivalent disconformity in the case of the south central inliers of the Midland Valley). | ||
| Definition of Upper Boundary: | Unconformity with the overlying Stratheden or Inverclyde groups (Late Devonian - Early Carboniferous age). | ||
| Thickness: | Up to 2700m in Lanarkshire and 2400m in Lothian. | ||
| Geographical Limits: | Southern part of the Midland Valley of Scotland (cf the Lanark basin of Bluck, 1978, and cf Smith, R A, 1995). | ||
| Parent Unit: | Old Red Sandstone Supergroup (ORS) | ||
| Previous Name(s): | Lower Old Red Sandstone Group
(LORS)
Lower Old Red Sandstone Group (LORS) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | South of the Hagshaw Hills, Lanarkshire, Scotland. See also stratotypes for component Greywacke Conglomerate, Swanshaw, Duneaton Volcanic and Auchtitench formations. | ||
| Reference(s): | |||
| Waters, C N, Gillespie, M R, Smith, K, Auton, C A, Floyd, J D, Leslie, A G, Millward, D, Mitchell, W I, McMillan, A A, Stone, P, Barron, A J M, Dean, M T, Hopson, P M, Krabbendam, M, Browne, M A E, Stephenson, D, Akhurst, M C, and Barnes, R P. 2007. Stratigraphical Chart of the United Kingdom: Northern Britain. (British Geological Survey.) | |||
| Bluck, B J. 1978. Sedimentation in a late orogenic basin: the Old Red Sandstone of the Midland Valley of Scotland. 249-278 in Crustal evolution in north-western Britain and adjacent regions. Bowes, D R, and Leake, B E (editors). Special Issue of the Geological Journal No. 10. | |||
| Mitchell, G H. 1962. The geology of the neighbourhood of Edinburgh. (Explanation of Sheet 32) Third Edition. (Reprinted 1980). Memoir of the Geological Survey of Great Britain (Scotland). | |||
| Smith, R A, 1995. The Siluro-Devonian evolution of the southern Midland Valley of Scotland. Geological Magazine, Vol.132, 503-513. | |||
| Browne, M A E, Smith, R A, and Aitken, A M. 2002. Stratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen. British Geological Survey Research Report RR/01/04. 67 pp. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S015 S014 S023 S014 S022 S024 S024 S032 S015 | |||