The BGS Lexicon of Named Rock Units — Result Details

Lamb Rig Siltstone Member

Computer Code: LAR Preferred Map Code: LAR
Status Code: Full
Age range: Telychian Age (ST) — Telychian Age (ST)
Lithological Description: Olive-yellow, poorly fossilferous siltstones and fine-grained sandstones, with well-developed concretions.
Definition of Lower Boundary: Conformable: Laminated silty sandstones with rare bioclasts, directly overlying sandy siltstones and fine-grained sandstones with abundant bioclasts (Grain Heads Siltstones Member).
Definition of Upper Boundary: Conformable: Olive siltstones underlying the lowest olive grey silty mudstone of the Baddingsgill Mudstone Member.
Thickness: 45-55m
Geographical Limits: Pentland Hills, Midland Valley.
Parent Unit: Wether Law Linn Formation (WLN)
Previous Name(s): Bed F (-2279)
Middle Part Of Fossiliferous Mudstones And Siltstones (-2280)
Middle Member Wether Law Linn Formation (-3508)
Unit D, Wether Law Linn Formation (-3509)
Beds At F (-1637)
Middle Part Of Bed C (-1011)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  North Esk river, west bank, 80m to 150m, downstream from confluence with Henshaw Burn. 
Partial Type Section  Top of Lamb Rig Siltstone Member and base of Grains Heads Siltstone Member, west bank, North Esk river, 80m downstream from confluence with Henshaw Burn. 
Type Section  Wether Law Linn, North bank 180m to 325m upstream of confluence with North Esk river. 
Reference(s):
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). 
Lamont, A, 1952. Ecology and correlation of the Pentlandian - a new division of the Silurian System in Scotland. 27-32 in Faunal and floral facies and zonal correlation. Dighton-Thomas, H (editor). Report of the 18th Session of the International Geological Congress, Great Britain, 1948, Pt.10. 
Tipper, J C, 1976. The stratigraphy of the North Esk Inlier. Scottish Journal of Geology, Vol.12, Pt, 15-22. 
Peach, B N and Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoir of the Geological Survey of the United Kingdom. 
Howell, H H and Geikie, A, 1861. The Geology of the neighbourhood of Edinburgh (1st edition). Memoir of the Geological Survey, Scotland. 
Robertson, G, 1989. A palaeoenvironmental interpretation of the Silurian rocks in the Pentland Hills, near Edinburgh, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences, Vol.80, 127-141. 
Robertson, G, 1986. North Esk Inlier. 174-185 in Lothian Geology. An Excursion Guide. McAdam, A D and Clarkson, E N K (editors). [Edinburgh: Scottish Academic Press.] 
Henderson, J and Brown, D J, 1870. On the Silurian rocks of the Pentland Hills. Transactions of the Edinburgh Geological Society, Vol.1, 266-272. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S032