Answers are grounded in this paper and cite their sources.
The stratigraphy of nine areas of Ordovician volcanic rocks flanking the Harlech Dome is dcscribed and a correlation of the Ordoyician volcanic succession from Arenig to Cader Idris proposed. Nine formations are distinguished which together form a distinct lithostratigraphic unit termed the Aran Volcanic Group. At least six disconformities can bc recognised within the Group.
No takes yet. Share an insight, caveat, or question.
J. Ridgway (1975) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: