The BGS Lexicon of Named Rock Units — Result Details

Porth y Nant Formation

Computer Code: POYN Preferred Map Code: notEntered
Status Code: Full
Age range: Floian Age (OFL) — Darriwilian Age (ODW)
Lithological Description: Pale green-grey mudstone.
Definition of Lower Boundary: Stratigraphic contact with Mynydd y Garn Formation (GARN) or unconformably upon Ordovican rocks of the Cemaes Group (CMS) or Neoproterozoic rocks, e.g. Mona Gneiss Assemblage - NMG.
Definition of Upper Boundary: Stratigraphic contact with Capel Parc Formation (CAPC).
Thickness: none recorded or not applicable
Geographical Limits: Anglesey.
Parent Unit: Llyn Alaw Group (ALAW)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
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