Abercorris GroupName
93013Province: Exposed in the area around Corris and Aberllefenni,(Merionethshire).
Geologic Age: Katian Age-Hirnantian Age
Other: Mudstone. Bedrock. Occurs onshore. Formed during the Rawtheyan Stage - to - Hirnantian Age (Ordovician Period) (447-443.8 Ma BP). Weathered dark blue blocky mudstone, well cleaved homogeneous blue mudstone (slate), dark blue micaceous mudstones often sandy or gritty, weathered to a dull bronze. 633 metres approx. Drawn at the base of the Red Vein Formation where blue mudstones with orange weathering rest conformably upon mottled mudstones of the Abercwmeiddaw Group. Drawn at the conformable upward passage of the Narrow Vein Formation where well cleaved slate passes into a dark blue micaceous sandy and gritty mudstone of the Garwedd-Wen Formation.
Usage: Current name
