The BGS Lexicon of Named Rock Units — Result Details

Hopcroft Hall Group

Computer Code: HPH Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Frasnian Age (DR) — Famennian Age (DA)
Lithological Description: Reddish purple,green and grey,calcareous silty mudstones with calcareous nodules and a few thin fine-grained sandstone bands.
Definition of Lower Boundary: Drawn at the base of metamorphised mudstones of the Hopcroft Hall Group where it rests unconformably upon an igneous infrurian a dark purple hernfels making the contact.
Definition of Upper Boundary: Drawn at the conformable upward passage of mudstones with derncation craks of the Hopcroft Hall Group to the calcareous sandstone shale facies of the Holt Farm Group.
Thickness: 24m approx.
Geographical Limits: Steeple Aston, Oxfordshire.
Parent Unit: Not Entered (?)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Steeple Aston, Oxfordshire. 
Reference(s):
none recorded or not applicable
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable