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Hoskyn Islands is a pair of small coral cays. They are located near the Tropic of Capricorn in the southern Great Barrier Reef, 107 km due east of Gladstone, Queensland, Australia, and 412 km north of the state capital Brisbane. The island is the fourth island in the Great Barrier Reef chain of islands (with the first being Lady Elliot Island), and is part of the Capricorn and Bunker Group of islands, forming part of the Capricornia Cays National Park as well as part of the Capricornia Cays Important Bird Area. Most people only see the island by the more easily reached Lady Musgrave Island, which can be readily reached by fast catamaran from the town of 1770, Queensland, or from Gladstone, both of which are located approximately five hours' drive north of Brisbane. The pair of Hoskyn cays are *East Hoskyn *West Hoskyn ==Geomorphology and landscape== The eastern cay is composed of shingle and supports vegetation similar to, although less well-developed than, that of Lady Musgrave Island. The western cay is composed of sand and its vegetation is similar to that of the larger sand cays Capricorn Group. Both cays have increased in size since 1936. The Capricorn and Bunker Cays form part of a distinct geomorphic province at the southern end of the Great Barrier Reef.〔Hopley, D. (1982) The Geomorphology of the Great Barrier Reef - Quaternary Development of Coral Reefs. Wiley-Interscience Publication, John Wiley and Sons Ltd., New York〕 The cays and their reefs lie on the western marginal shelf, and are separated from the mainland by the Curtis Channel. The cays are not generally visible from the mainland, although Masthead Island may be viewed from Mount Larcom on a clear day. Geologically the cays are young, having developed during the Holocene period, they are mostly around 5000 years old. The sea level was much lower during the last Ice Age (at the end of the Pleistocene period) and the coastal plane on which today’s reefs and cays developed was completely exposed. Early in the Holocene (around 10,000 years ago) the sea level began to rise, until it stabilised at its present level around 6000 years ago. Once the sea level stabilised, it was possible for reef flats to expand and provide potential sites for the formation of cays. Hoskyn Reefs is a Closed Ring Reef.〔William Graham Henderson Maxwell - Atlas of the Great Barrier Reef Elsevier, 1968〕 The cays occur on planar reefs of various sizes and with various levels of exposure to the prevailing winds. These factors have largely determined cay size and composition, which consists either of shingle, sand, or a mixture of both. Cay stability is profoundly affected by cyclonic disturbance. The coral cays belong to two distinct types:〔Fairbridge, R. W. 1950b. Recent and Pleistocene coral reefs of Australia. J. Geol. 58: 330-401〕 # Vegetated sand cays: Hoskyn (West). # Shingle cays: Hoskyn (East). The sand cay is located to the lee of their reef flat, whereas the shingle cay is located on the windward side.〔Mather and Bennett, 1993 A Coral Reef Handbook: a guide to the geology, flora and fauna of the Great Barrier Reef, 3rd Ed. Australian Coral Reef Society Handbook Series〕 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「Hoskyn Islands」の詳細全文を読む スポンサード リンク
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