The BGS Lexicon of Named Rock Units — Result Details

Henshaw Formation

Computer Code: HSW Preferred Map Code: HSW
Status Code: Full
Age range: Sheinwoodian Age (SS) — Homerian Age (SH)
Lithological Description: Red medium- and coarse-grained sandstones and conglomerates with finer grained sediments.
Definition of Lower Boundary: Conformable: lowest pebble grit horizon immediately overlying red Wether Law Linn Formation shales.
Definition of Upper Boundary: Not seen - unconformably overlain by Greywacke Conglomerate Formation (lower 'Old Red Sandstone') and faulted against Kinnesswood Formation (Inverclyde Group).
Thickness: At least 725m
Geographical Limits: Pentland Hills, Midland Valley.
Parent Unit: North Esk Group (NSK)
Previous Name(s): Lower Red Sandstone (-3481)
Bed D (-2856)
Red Sandstone Series (-327)
Upper Red Sandstone (URS)
Upper Argillaceous Beds (UARG)
Middle Red Sandstone (MRS)
Lower Argillaceous Beds (LARG)
Beds At J To M (-4102)
Red Igneous Conglomerate And Sandstone (-4103)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Baddingsgill Reservoir shore section to Lyne Water, 20m west of footbridge to 630m NE of Little Hill summit 
Reference Section  North Esk river and Henshaw Burn, 115m to 225m upstream from confluence. 
Partial Type Section  Top of Baddingshill Mudstone Member of Wether Law Linn Formation and base of Henshaw Formation, North Esk River, west bank 115m upstream from confluence with Henshaw Burn. 
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). 
Peach, B N and Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoir of the Geological Survey of the United Kingdom. 
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. 
Howell, H H and Geikie, A, 1861. The Geology of the neighbourhood of Edinburgh (1st edition). Memoir of the Geological Survey, Scotland. 
Tipper, J C, 1976. The stratigraphy of the North Esk Inlier. Scottish Journal of Geology, Vol.12, Pt, 15-22. 
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. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S032 S024