The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also extends northwards into Greenland and Svalbard. These areas were a part of the ancient continent of Euramerica/Laurussia. In Britain it is a lithostratigraphic unit to which stratigraphers accord supergroup status and which is of considerable importance to early paleontology. For convenience the short version of the term, ORS is often used in literature on the subject. The term was coined to distinguish the sequence from the younger New Red Sandstone which also occurs widely throughout Britain.
Kerrera is an island in the Scottish Inner Hebrides, close to the town of Oban. In 2016 it had a population of 45, divided into two communities in the north and south of the island.
The Mainland, also known as Hrossey and Pomona, is the main island of Orkney, Scotland. Both of Orkney's burghs, Kirkwall and Stromness, lie on the island, which is also the heart of Orkney's ferry and air connections.
Eday is one of the islands of Orkney, which are located to the north of the Scottish mainland. One of the North Isles, Eday is about 24 kilometres from the Orkney Mainland. With an area of 27 km2 (10 sq mi), it is the ninth-largest island of the archipelago. The bedrock of the island is Old Red Sandstone, which is exposed along the sea-cliffs.
The Barrel of Butter, formerly known as Carlin Skerry, is a skerry in Scapa Flow in the Orkney Islands.
The Orcadian Basin is a sedimentary basin of Devonian age that formed mainly as a result of extensional tectonics in northeastern Scotland after the end of the Caledonian orogeny. During part of its history, the basin was filled by a lake now known as Lake Orcadie. In that lacustrine environment, a sequence of finely bedded sedimentary rocks was deposited, containing well-preserved fish fossils, with alternating layers of mudstone and coarse siltstone to very fine sandstone. These flagstones split easily along the bedding and have been used as building material for thousands of years. The deposits of the Orcadian Basin form part of the Old Red Sandstone (ORS). The lithostratigraphic terms lower, middle and upper ORS, however, do not necessarily match exactly with sediments of lower, middle and upper Devonian age, as the base of the ORS is now known to be in the Silurian and the top in the Carboniferous.
The geology of the Orkney islands in northern Scotland is dominated by the Devonian age Old Red Sandstone (ORS). In the southwestern part of Mainland, this sequence can be seen to rest unconformably on a Moinian type metamorphic basement.
The Ridgeley sandstone is a sandstone or quartzite of Devonian age found in the Appalachian Mountains of Pennsylvania, Maryland, West Virginia, and Virginia, United States. The Ridgeley is fine-grained, siliceous, calcareous in its lower strata, sometimes fossiliferous, and sometimes locally pebbly or conglomeritic. Varying in thickness from 12 to 500 feet, this rock slowly erodes into white quartz sand that often washes or blows away, but sometimes accumulates at large outcrops. When freshly broken, the rock is white, but outcrop surfaces are often stained yellowish by iron oxides.
The Caithness Flagstone Group is a Devonian lithostratigraphic group in northern Scotland. The name is derived from the traditional county of Caithness where the strata are well exposed, especially in coastal cliffs.
The Eday Group is a Devonian lithostratigraphic group in Orkney, northern Scotland. The name is derived from the island of Eday where the strata are exposed in coastal cliffs.
St Magnus Bay is a large coastal feature in the north-west of Mainland Shetland, Scotland. Roughly circular in shape with a diameter of about 19 kilometres (12 mi), it is open to the North Atlantic Ocean to the west. The indented coastline to the north, south and east between Esha Ness in the north and the Ness of Melby in the south contains numerous bays, firths and voes and there are several islands around the perimeter. The waters of the bay are up to 165 metres (541 ft) deep and may have been the site of a substantial meteor impact.
The Cosheston Group is an early Devonian lithostratigraphic group in west Wales. The name is derived from the village of Cosheston in south Pembrokeshire. The Group comprises the Llanstadwell, Burton Cliff, Mill Bay, Lawrenny Cliff and New Shipping formations. The strata are exposed in the Milford Haven area of southern Pembrokeshire where several partial type sections are defined. The outcrop extends around the northern and southern shores of the Haven. It is bounded to the north by the Benton Fault between the villages of Rosemarket and Lawrenny, and extends east to New Shipping and west almost to the town of Milford Haven itself. The rocks of this group have also previously been known as the Cosheston Beds.
The Milford Haven Group is a late Silurian to early Devonian lithostratigraphic group in west Wales. The name is derived from the estuary and town of Milford Haven in south Pembrokeshire. The Group comprises calcareous marls with occasional sandstones along with conglomerates and breccias.
The Stratheden Group is a Devonian lithostratigraphic group in southern Scotland and northernmost England. Occasionally pebbly, this red-brown and yellow sandstone dominated unit also contains siltstones and mudstones. It is encountered in Arran in the west and across the Midland Valley to the northeastern parts of Fife in the east. The name is derived from Stratheden in Fife. The rocks of the Stratheden Group have also previously been referred to as the Upper Old Red Sandstone. It unconformably overlies a variety of other rock sequences including the Strathmore Group around Dumbarton, Stirling and Arran and the Arbuthnott-Garvock Group in Fife and the Kinross area.
The Arbuthnott-Garvock Group is a Devonian lithostratigraphic group in central Scotland. The name is derived from the village of Arbuthnott in Aberdeenshire and the Hill of Garvock near Laurencekirk. The group comprises the previously separate overlying Garvock Group and the underlying Arbuthnott Group.
The Strathmore Group is a Devonian lithostratigraphic group in central Scotland. Its sandstones are interbedded with siltstones which interfinger with conglomerates. It is encountered from Arran in the west across the Midland Valley to Stonehaven in the east. The name is derived from Strathmore, Angus where this sequence occupies the axis of the Strathmore Syncline which runs for many tens of miles parallel to and south of the Highland Boundary Fault. The rocks of the Strathmore Group have also previously been referred to as the Strathmore Beds.
The Dingle Group is a Devonian lithostratigraphic group in the Dingle peninsula, Munster, Ireland. The name is derived from the town of Dingle and the peninsula to which it gives its name where the strata are exposed on mountainsides and in coastal cliffs.
The Smerwick Group is a Devonian lithostratigraphic group in the Dingle peninsula, Munster, Ireland. The name is derived from the village of Smerwick where the strata are exposed in coastal sections on either side of Smerwick Harbour, a deep bay on the peninsula's northwest coast.
The geology of Exmoor National Park in south-west England contributes significantly to the character of a landscape which was designated as a national park in 1954. The bedrock of the area consists almost wholly of a suite of sedimentary rocks deposited during the Devonian, a period named for the English county of Devon in which the western half of the park sits. The eastern part lies within Somerset and it is within this part of the park that limited outcrops of Triassic and Jurassic age rocks are to be found.
Scotland 