41. The underlying geology is of Old Red Sandstone overlying marl, and processes of tie beams and buttresses. 42. The site overlies Old Red Sandstone . 43. On the eastern side of the county the Dalradian schists are covered unconformably by the Old Red Sandstone . 44. The rocks of the Stratheden Group have also previously been referred to as the Upper Old Red Sandstone . 45. The Afon Dringarth flows across ground formed from the Old Red Sandstone laid down during the Devonian period. 46. The Old Red Sandstone and the contemporary volcanics and marine sediments found in Devon originated from these processes. 47. Indeed, Brown Clee is considered to be one of the best exposures of Old Red Sandstone that exists. 48. It is of Old Red Sandstone . 49. The bedrock of the island consists of flat layers of weathered Middle Old Red Sandstone , known as Rousay flags. 50. In 1831, Fleming found some fossils which he recognized as fish in the Old Red Sandstone units at Fife.
