Остров Рамси: Геология, История и Природа Уэльса

Island in Pembrokeshire, Wales
the island in Wales

Ramsey Island (Welsh: Ynys Dewi) is an island about off St David's Head in Pembrokeshire on the northern side of St Brides Bay, in southwest Wales, in the community of St Davids and the Cathedral Close. It is in area. Ramsey means (in Old Norse) Hrafn's island. In Welsh the island is named after Saint David (Dewi Sant), the patron saint of Wales. It was the home of his confessor, Saint Justinian. The nearest large settlement is the city of St David's. Ramsey Island is less than long and its highest point is above sea level at Carnllundain, and is listed as a HuMP. It is the fourth largest island in Wales, after Anglesey, Holy Island and Skomer, and is surrounded by a number of islets, tidal islands and rocks.

The island has a diverse geology for a relatively small area; it comprises sedimentary, volcanic and intrusive igneous rocks dating from the early Palaeozoic Era. The larger part of the north of the island is formed from mudstones of the Tetragraptus Mudstone Formation (also known as the 'Penmaen Dewi Shale Formation' and again as the 'Road Uchaf Formation' (sic) after the Rhod Uchaf locality on the island's east coast). However Carnysgubor stands proud to their west as it is formed from a more resistant microtonalite intrusion. In contrast the coastal cliffs between Trwyn drain du and Trwyn Sion Owen and also between Trwyn Ogof Hen and Rhod Uchaf are formed by sedimentary rocks, the mica rich Lingula Flags and the sandstones and mudstones of the Ogof Hen Formation. The rock strata are typically steeply tilted and commonly faulted. Running NW–SE across the centre of the island from Aber Mawr to the vicinity of The Bitches is a band of late Arenig age tuffs and 'pencil slates' assigned to the Aber Mawr Formation. Its boundary with the sediments to the north is a fault. The south of the island is dominated by a rhyolite intrusion as are the islets off its southern coast. To the west of the Ramsey Fault which runs from Aber Mawr to Porth Lleuog, is Carnllundain which is formed from the tough rhyolitic tuffs of the Carn Llundain Formation. These tuffs arose as volcanic ash falls, ash flows and turbidite deposits. Smaller areas of dark grey mudstones interbedded with debris flows grouped together as the Porth Llauog Formation occur around the margins of the rhyolite. Part of the southern margin of the inlet of Aber Mawr is characterised by the mudstones and sandstones of the Trwyn Llundain Formation, a part of the Solva Group of Cambrian rocks.

Surveys in the 1990s and more recently discovered evidence of prehistoric cairns, field systems, barrows and other anomalies which suggest human activity on the island dates back up to 5,000 years. Mediaeval sites include a holy well and cemetery from the 9th century.

From 1082, the island was part of the cantref of Dewisland under the control of the bishops of St David's. In the 12th century, it was a place of pilgrimage; St Tyfanog's Chapel existed up to the 1600s, when it was described as "decayed", and there may also have been a chapel to St Justinian. In the 13th century, the island was reported to be fertile, producing beef, sheep, goats, wheat, barley and oats. In the 14th century, of the island supported horses, cattle and sheep. Rabbits, rushes, heath and birds' eggs were harvested. A farmhouse, corn mill and lime kiln were recorded in the 16th century, but the farm building was a ruin by the early 19th century. The mill and kiln were in operation until the early 20th century, and in 1905 the island was sold into private hands and ceased being an ecclesiastical holding.

Owned and managed by the Royal Society for the Protection of Birds (RSPB), the island has spectacular bird cliffs, coastal scenery and heathland. It is one of the best sites in Wales to see choughs, which are attracted by an ample supply of dung beetles. Other breeding species include ravens, common buzzards, peregrines, northern wheatears, gulls, auks, Manx shearwaters, razorbills and guillemots. Ramsey has the most important grey seal breeding colony in southern Britain, with over 400 seal pups born each autumn. With a permanent population of just two human residents, the RSPB Warden and Assistant Warden who live in a farmhouse there, the island is otherwise uninhabited. Tourist boats sail around the island and a ferry service run by Thousand Islands Expeditions operates from Easter to 31 October from St Davids Lifeboat Station on the mainland.