Uriconian

The name relates to Uriconio, the Latin name for an Iron Age hillfort on the summit of the Wrekin, a hill formed of Uriconian rock.

[2] The Uriconian have long thought to be older than the Longmyndian and generally outcrop to the southeast of the latter within northeast-southwest trending lineaments suggesting basement influence for the regional structure.

[1] The Uriconian rocks outcrop in areas from Wellington, Shropshire to Primrose Hill on the southwest side of The Wrekin, east of Caer Caradoc and in the Craven Arms Inlier.

[1][3] Primarily the strata exist as fault-bounded slices within splays of, and to the southeast of, the main Church Stretton fault system.

The Uriconian rocks comprise both intermediate to acidic and basic (bimodal) volcanic suites that reflect largely intraplate origins for the complex although some subduction signatures have been identified.

Relationships to other potential lateral equivalents (from the eastern part of the Avalonia palaeo micro-continent known as the Monian terrane) are still conjectural albeit to varying degrees.

[5] This leads to suggest that the area was affected by (Uriconian) volcanism and associated events between 570-550 Ma including the intrusion of the Ercall Granophyre.