Walking further west along the seashore at Ogmore-by-Sea, the outcropping rocks change from the rock pavement of Pembroke Limestone of Carboniferous age to relatively more recent Triassic sediments from roughly 250 – 200 million years ago. The rock consists of a matrix of red sand and silt in which are embedded rounded and sub-angular pebbles of the Pembroke Group limestone, and sometimes enormous multi-ton boulders. Rock from the Permian era which follows chronologically after the Carboniferous and before the Triassic is entirely absent. The Triassic rock is therefore said to lie unconformably on the Carboniferous ones. The photos show details of this rocky headland, and you can find more information online provided by the Geologist’s Association, South Wales Group in their leaflet “Geological Walks in Wales – Ogmore-by-Sea, Vale of Glamorgan” in Locality 3.
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