The BGS Lexicon of Named Rock Units — Result Details

Abercwmeiddaw Group

Computer Code: ABG Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Rawtheyan Stage (OW) — Rawtheyan Stage (OW)
Lithological Description: Thickly-bedded, mottled, grey-blue mudstones, passing locally into well cleaved slates.
Definition of Lower Boundary: Drawn at the base of the Abercwmeiddaw Group where pale greyish blue, thickly bedded mudstones conformably rest upon black shales of the Nod Glas Formation.
Definition of Upper Boundary: Drawn at the conformable upward passage of the Abercwmeiddaw Group where mottled mudstones pass into blue mudstones with orange weathering of the Red Vein Formation.
Thickness: 450 metres approx.
Geographical Limits: The district around Corris and Aberllefenni (Merionethshire).
Parent Unit: Not Entered (?)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Abercwmeiddaw Quarry, near Corris, Merioneth. 
Pugh, W. 1923. The geology of the district around Corris and Aberllefeni (Merionethshire). Quarterly Journal of the Geological Society of London, Vol.79, p.512, 520-5. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable