|
The Islands of the Firth of Clyde are the fifth largest of the major Scottish island groups after the Inner and Outer Hebrides, Orkney and Shetland. They are situated in the Firth of Clyde between Ayrshire and Argyll. There are about forty islands and skerries, of which only four are inhabited and only nine larger than . The largest and most populous are Arran and Bute, and Great Cumbrae and Holy Isle are also served by dedicated ferry routes.〔("Destinations" ). Caledonian MacBrayne. Retrieved 22 Jan 2011.〕〔("Getting Here" ). The Holy Isle Project. Retrieved 12 May 2012.〕 Unlike the four larger Scottish archipelagos, none of the isles in this group are connected to one another or to the mainland by bridges. The geology and geomorphology of the area is complex and the islands and the surrounding sea lochs each have distinctive features. The influence of the Atlantic Ocean and the North Atlantic Drift create a mild, damp oceanic climate. The larger islands have been continuously inhabited since Neolithic times, were influenced by the emergence of the kingdom of Dál Riata from 500 AD and then absorbed into the emerging Kingdom of Alba under Kenneth MacAlpin. They experienced Norse incursions during the early Middle Ages and then became part of the Kingdom of Scotland in the 13th century. There is a diversity of wildlife, including three species of rare endemic tree. == Geology and geography == The Highland Boundary Fault runs past Bute and through the northern part of Arran, so from a geological perspective some of the islands are in the Highlands and some in the Central Lowlands.〔Gillen (2003) p. 28〕 As a result, Arran is sometimes referred to as "Scotland in miniature" and the island is a popular destination for geologists, who come to see intrusive igneous landforms such as sills and dykes as well as sedimentary and metasedimentary rocks ranging widely in age.〔McKirdy ''et al.'' (2007) pp. 297- 301〕 Visiting in 1787, the geologist James Hutton found his first example of an unconformity there and this spot is one of the most famous places in the study of geology.〔(【引用サイトリンク】title=Hutton's Unconformity - Lochranza, Isle of Arran, UK - Places of Geologic Significance on Waymarking.com )〕 A group of weakly metamorphosed rocks that form the Highland Border Complex lie discontinuously along the Highland Boundary Fault. One of the most prominent exposures is along Loch Fad on Bute.〔Gillen (2003) pp. 89-90〕 Ailsa Craig, which lies some south of Arran, has been quarried for a rare type of micro-granite containing riebeckite known as "Ailsite" which is used to make curling stones. As of 2004, 60 to 70% of all curling stones in use were made from granite from the island.〔Roch, John (27 October 2004) ("Puffins Return to Scottish Island Famous for Curling Stones" ). National Geographic News. Retrieved 29 August 2010〕 In common with the rest of Scotland the Firth of Clyde was covered by ice sheets during the Pleistocene ice ages and the landscape is much affected by glaciation.〔Gillen (2003) pp. 174-86〕 Arran's highest peaks may have been nunataks at this time.〔McKirdy ''et al.'' (2007) pp. 297- 301.〕 After the last retreat of the ice sea level changes and the isostatic rise of land makes charting post glacial coastlines a complex task but the resultant clifflines behind raised beaches are a prominent feature of the entire coastline.〔McKirdy ''et al.'' (2007) p. 28.〕〔Ritchie, W. ("Beaches of Cowal, Bute & Arran" ) (1975) Scottish Natural Heritage. (Originally published by the Countryside Commission for Scotland). pp. 6-9〕 The soils of the islands reflect the diverse geology. Bute has the most productive land, and a pattern of deposits that is typical of the southwest of Scotland. There is a mixture of boulder clay and other glacial deposits in the eroded valleys, and raised beach and marine deposits elsewhere, especially to the south and west which result in a machair landscape in places, inland from the sandy bays, such as Stravanan.〔("Bute's Geology & Geomorphology" ) Bute-gateway.org. Retrieved 20 Jan 2011.〕〔("Bute Map 6: Garroch Head to Stravannan Bay" ) (pdf) scapetrust.org. Retrieved 20 Jan 2011.〕 The Firth of Clyde, in which these island lie, is north of the Irish Sea and has numerous branching inlets, some of them substantial features in their own right. These include Loch Goil, Loch Long, Gare Loch, Loch Fyne and the estuary of the River Clyde. In places the effect of glaciation on the seabed is pronounced. For example, the Firth is deep between Arran and Bute, although they are only apart.〔Gillen (2003) p. 177〕 The islands are all exposed to wind and tide and various lighthouses, such as those on Ailsa Craig, Pladda and Davaar act as an aid to navigation.〔("Lighthouse Library" ) Northern Lighthouse Board. Retrieved 14 July 2007.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Islands of the Clyde」の詳細全文を読む スポンサード リンク
|