The Conglomerates of Allt Goch and Mathrafal-ffrîdd (Montgomeryshire)

Abstract

The following is a description of the conglomerates which crop out at Allt Goch and Mathrafal-ffrîdd near Meifod (Montgomeryshire) and which were examined on the suggestion of Professor W. B. R. King. Allt Goch is about 4 miles north of Mathrafal-ffrîdd, and the two localities lie on opposite flanks of the anticlinal structure which passes through Pont Robert and which, brings up Ashgillian and Caradocian rocks. The conglomerates themselves are at, or near, the base of the Valentian. At other places in the neighbourhood the basal member of the Silurian consists of coarse deposits (sandstones, etc.), but “they very probably do not represent the lowest zones that are found in Central Wales” (I).