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The Bishops and Clerks are a group of rocks and islets situated in St George's Channel 1 to 2 miles west of Ramsey Island, Pembrokeshire, Wales. They comprise four distinct groups of islets. From the north these are: *North Bishop (44 metres, 144 feet) *Carreg Rhoson (44 metres, 144 feet) *Carreg Rhoson E Island (30 metres, 98 feet) * *Maen Rhoson *Daufraich * *Maen Daufraich * *Moelyn * *Cribog *Emsger or South Bishop (37 metres, 121 feet) In addition, the three small wave-washed rocks of Carreg-trai, Llechau-isaf and Llechau-uchaf sit in the waters between the Bishops and Clerks and Ramsey Island and the Welsh mainland. The South Bishop Lighthouse is built upon Emsger or South Bishop. Thirteen or so shipwrecks are recorded in the waters immediately surrounding the islands, notably North Bishop.〔http://www.pembrokeshirecoast.org.uk/files/files/Dev%20Plans/AdoptedSPG/SCA19%20%20Bishop%20and%20Clerks.pdf Pembrokeshire Coast National Park planning document〕 ==Geology== The two northerly islet groups are formed from gabbro, a hard-wearing rock of igneous origin whilst those of the Daufraich group to their south (and indeed Llechau-isaf) are formed from microtonalite, another intrusive igneous rock. The most southerly, Emsger is formed from rhyolite. All these are of probable lower Palaeozoic origin. Llechau-uchaf is formed from the late Cambrian 'Lingula Flags' whilst Carreg-trai is formed from Ordovician acid tuffs of the Llanrian Volcanic Formation.〔British Geological Survey 1992 1:50,000 scale provisional geological map sheet 209 (England and Wales) ''St David's''〕 The submarine geology between the main groups is formed by sandstones and mudstones of Cambro-Ordovician age, though the bedrock is partly covered by sand and gravel.〔http://www.pembrokeshirecoast.org.uk/files/files/Dev%20Plans/AdoptedSPG/SCA19%20%20Bishop%20and%20Clerks.pdf Pembrokeshire Coast National Park planning document〕 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「Bishops and Clerks」の詳細全文を読む スポンサード リンク
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