The Longmyndian Rocks of the Old Radnor Inlier, Welsh Borderland

Two formations are named in the presumed Precambrian sedimentary rocks of the Old Radnor Inlier. The Strinds Formation comprises fine‐ to medium‐grained sandstones and pebbly sandstones. Grain‐size, texture, clast types, and lithological invariance support correlation with the homogeneous and cross‐bedded sandstone facies of the Bayston‐Oakswood Formation of the Longmyndian, assigned to a braided alluvial plain environment. The Yat Wood Formation comprises fine‐grained sandstones, siltstones, and laminated mudstones. It may be equivalent to some part of the Burway, Synalds, or Lightspout Formation. The Strinds and Yat Wood Formations are petrographically similar to each other and to the type Lonmyndian, and were sourced either directly or indirectly from a magmatic arc. The Strinds and Yat Wood Formations are seen only in faulted contact, and the inlier itself is partly or wholly bounded by strands of the Church Stretton fault zone. Similar faulted relationships are seen further northeast along the system at Pedwardine and in the Church Stretton area. A fault explanation for the juxtaposition of contrasting facies is favoured over that of an original unconformity of Strinds on Yat Wood Formation.