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Tryon Island is a coral cay located in the southern Great Barrier Reef, 86 km northeast of Gladstone, Queensland, Australia, and 465 km north of the state capital Brisbane. The island is a protected area and forms part of Capricornia Cays National Park. It is part of the Capricornia Cays Important Bird Area. The cay covers an area of 0.21 square kilometres〔 and is surrounded by a coral reef that is partially exposed at low-tide. ==Geomorphology and landscape== On Tryon Island, there is beach rock along the north western and south eastern beaches. The cay has in the past been covered with dense vegetation. 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. Tryon Island is a vegetated sand cay〔Fairbridge, R. W. 1950b. Recent and Pleistocene coral reefs of Australia. J. Geol. 58: 330–401〕 placed atop of a platform reef.〔William Graham Henderson Maxwell - Atlas of the Great Barrier Reef Elsevier, 1968〕 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「Tryon Island」の詳細全文を読む スポンサード リンク
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