The BGS Lexicon of Named Rock Units — Result Details

Mynydd Bonafon Formation

Computer Code: BONA Preferred Map Code: notEntered
Status Code: Full
Age range: Ediacaran Period (AD) — Ediacaran Period (AD)
Lithological Description: Contact metamorphosed laminated semipelite and quartzite, latter locally cross-bedded.
Definition of Lower Boundary: Stratigraphic contact with underlying Gwalchmai Formation (GWALC).
Definition of Upper Boundary: Unconformably overlain by Ordovician rocks, eg. Llyn Alaw Group (ALAW).
Thickness: none recorded or not applicable
Geographical Limits: Anglesey.
Parent Unit: Llynn Maelog Group (LMG)
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