The BGS Lexicon of Named Rock Units — Result Details

Superstes Mudstone Formation

Computer Code: SMU Preferred Map Code: SMU
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Mudstone.
Definition of Lower Boundary: Interfingers with Benan Conglomerate. Also rests conformably on Stinchar Limestone.
Definition of Upper Boundary: Overlain/interfingers with Benan Conglomerate.
Thickness: 0 to 25m
Geographical Limits: Girvan area, southwest Scotland.
Parent Unit: Barr Group (BARR)
Previous Name(s): Didymograptus Shales (-1832)
Didymograptus Superstes Mudstones (-4889)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Benan Burn. 
Reference(s):
Ince, D, 1984. Sedimentation and tectonism in the Middle Ordovician of the Girvan district, north west Scotland. Transactions of the Royal Society of Edinburgh. Earth Sciences, Vol.75 (2), p.225-237. 
Lapworth, C, 1882. The Girvan Succession. Quarterly Journal of the Geological Society of London, Vol. 38, 537-666. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S008