sentences:  Triassic rocks provided the Radyr stone and also the Quarella stone which was worked at Bridgend.Sutton Stone from South Wales' Jurassic outcrop is a highly regarded limestone freestone that has been used in construction throughout the Vale of Glamorgan, it was also shipped over the Bristol Channel to North Devon and North Cornwall which are both deficient in limestone.The micaceous sandstones of Carmarthenshire's Tilestones Formation were formerly worked to provide roofing material, as were similar flaggy sandstones elsewhere, at least until the burgeoning of the North Wales slate industry in the nineteenth century.