The BGS Lexicon of Named Rock Units — Result Details

Mynydd Eilian Formation

Computer Code: MYEI Preferred Map Code: notEntered
Status Code: Full
Age range: Darriwilian Age (ODW) — Darriwilian Age (ODW)
Lithological Description: Pale green-grey mudstone. Within Ogof Fach Member (OGOFF): disturbed beds of dark grey mudstone conglomerate with beds of high matrix sandstone and massive sandstone.
Definition of Lower Boundary: Stratigraphic contact with underlying Porth y Corwgl Member - CORWG (Capel Parc Formation).
Definition of Upper Boundary: Unconformably overlain by Silurian rocks, e.g. Copper Mine Formation (COMN).
Thickness: none recorded or not applicable
Geographical Limits: Anglesey.
Parent Unit: Llyn Alaw Group (ALAW)
Previous Name(s): Parys Green Beds (PARYG)
Parys Group (PARY)
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
Reference(s):
Bates, D E B. 1974. The structure of the Lower Palaeozoic rocks of Anglesey, with special reference to faulting. Geological Journal, 9(1), 39-60. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable