Age of the ordovician andesitic conglomerate of castle hill, Montgomery, Powys, Wales

Abstract
Marine fossils including Broeggerolithus broeggeri (Bancroft) and Salterolithus caractaci (Murchison) collected from strata surrounding the andesitic conglomerate of Castle Hill, Montgomery prove that the volcanic event which produced it, and possibly also the andesite of Moel‐y‐Golfa 10 miles to the NNE, was of Caradoc (early Soudleyan) age.