The BGS Lexicon of Named Rock Units — Result Details

Milford Haven Subgroup

Computer Code: MIH Preferred Map Code: notEntered
Status Code: Full
Age range: Ludlow Epoch (SU) — Pragian Age (DP)
Lithological Description: Hard, red calcareous marls with sporadic red and green sandstones. Basal beds of green marl, conglomerate and breccia are also present. (Correlative of Milford Haven Group-Red Marl Group).
Definition of Lower Boundary: Drawn at base of green marls and conglomerate to north, and of red marls and breccia to the south of Milford Haven where they rest conformably on the Benton Rhyolitic Group to the north and Gray Sandstone Group to the south.
Definition of Upper Boundary: Drawn at conformable and unconformable upward passage from red marls to sandstone and marls of the Cosheston Group, north of Milford Haven and to the Ridgeway Conglomerate, south of the Haven respectively.
Thickness: About 1500m
Geographical Limits: Southwest Wales.
Parent Unit: Daugleddau Group (DAUG)
Previous Name(s): Downton Subgroup (DOW)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Milford Haven area, Dyfed, Wales. 
Reference(s):
Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. 
Strahan, A and others, 1909. South Wales District-Pembrokeshire. Summary of Progress of the Geological Survey of Great Britain, for 1908, p.33. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E244 E245 E229