Standing at Tog Hill, you are on the western edge of the Jurassic limestone belt that stretches from Dorset to Lincolnshire. The oolitic limestone beneath your feet formed around 175 million years ago on the bed of a warm, shallow tropical sea. Tiny spheres of calcium carbonate — ooliths — accumulated and lithified into the honey-coloured stone that built the Cotswold villages. The escarpment here is the result of differential erosion: hard limestone caps the ridge while softer clays were stripped from the vale below. The dramatic westward views from Tog Hill's picnic site reveal the full extent of this geological drama — the flat Severn Vale stretching to the Welsh hills.
“Tiny spheres of calcium carbonate — ooliths — accumulated and lithified into the honey-coloured stone that built the Cotswold villages.”
