The BGS Lexicon of Named Rock Units — Result Details

Cwm Yr Aethnen Mudstones Formation

Computer Code: CYA Preferred Map Code: Cya
Status Code: Pending Upgrade
Age range: Llandovery Epoch (SL) — Llandovery Epoch (SL)
Lithological Description: Dark blue mudstones and laminated siltstones.
Definition of Lower Boundary: Not defined.
Definition of Upper Boundary: Not defined.
Thickness: 0 to 150m
Geographical Limits: Not defined.
Parent Unit: Not Available (!)
Previous Name(s): Cwm Yr Aethnen Mudstones (-2733)
Cwm Yr Aethnen Shales (-2734)
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
Reference(s):
Bassett, D A, Whittington, H B and Williams, A. 1966. The stratigraphy of the Bala district, Merionethshire. Quarterly Journal of the Geological Society of London, Vol.122, 219-271. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E120 E136