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 725 m.
Geographical Limits: Pentland Hills, Midland Valley.
Parent Unit: North Esk Group (NSK)
Previous Name(s): Upper Red Sandstone (URS)
Upper Argillaceous Beds (UARG)
Middle Red Sandstone (MRS)
Lower Argillaceous Beds (LARG)
Bed D [Obsolete Name and Code: Use HSW] (-2856)
Red Sandstone Series [Obsolete Name and Code: Use HSW] (-327)
Beds At J To M [Obsolete Name and Code: Use HSW] (-4102)
Red Igneous Conglomerate and Sandstone [Obsolete Name and Code: Use HSW] (-4103)
Lower Red Sandstone [Obsolete Name and Code: Use YWS, HSW] (-3481)
Upper Red Sandstone (URS)
Upper Argillaceous Beds (UARG)
Middle Red Sandstone (MRS)
Lower Argillaceous Beds (LARG)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Baddingsgill Reservoir shore section to Lyne Water, 20 m west of footbridge to 630 m NE of Little Hill summit. 
Reference Section  North Esk river and Henshaw Burn, 115 m to 225 m 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 115 m upstream from confluence with Henshaw Burn. 
Reference(s):
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. 
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.] 
Peach, B N and Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoir of the Geological Survey of the United Kingdom. 
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. 
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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S032 S024