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Wrangel Island () is an island in the Arctic Ocean, between the Chukchi Sea and East Siberian Sea. Wrangel Island lies astride the 180° meridian. The International Date Line is displaced eastwards at this latitude to avoid the island as well as the Chukchi Peninsula on the Russian mainland. The closest land to Wrangel Island is tiny and rocky Herald Island located to the east.〔Kos,ko, M.K., M.P. Cecile, J.C. Harrison, V.G. Ganelin, N.V., Khandoshko, and B.G. Lopatin, 1993, Geology of Wrangel Island, Between Chukchi and East Siberian Seas, Northeastern Russia. Bulletin 461, Geological Survey of Canada, Ottawa Ontario, 101 pp.〕 The distance to the closest point on the mainland is . Wrangel Island may have been the last place on earth where mammoths survived. Nearly all of Wrangel Island, and Herald Island, are a federally protected nature sanctuary administered by Russia's Ministry of Natural Resources and Environment. The island, and its surrounding waters, were classified as a "Zapovednik" (a "strict nature reserve") in 1976 and, as such, receive the highest level of protection and exclude practically all human activity other than for scientific purposes. The Chukotka Regional government extended the marine protected area out to 24 nautical miles in 1999. As of 2003, there were four rangers who reside on the island year-round. In addition a core of about 12 scientists conduct research during the summer months. Wrangel Island is about wide and in area. It consists of a southern coastal plain that is as wide as ; a central belt of low-relief mountains; and a northern coastal plain that is as wide as . The east-west trending central mountain belt, the Tsentral'nye Mountain Range, is as much as wide and long from coast to coast. Typically, the mountains are a little over above mean sea level. The highest mountain on this island is Sovetskaya Mountain with an elevation of above mean sea level. The east-west trending mountain range terminates at sea cliffs at either end of the island.〔 Wrangel Island belongs administratively to the Chukotka Autonomous Okrug of the Russian Federation. This rocky island has a weather station and, formerly, two Chukchi fishing settlements on the southern side of the island (Ushakovskoye〔 and Zvyozdny on the shore of Somnitelnaya Bay〔(Ministry of Natural Resources of the russian Federation – History of Wrangel Island )〕). ==Geology== Wrangel Island consists of folded, faulted, and metamorphosed volcanic, intrusive, and sedimentary rocks ranging in age from Upper Precambrian to Lower Mesozoic. The Precambrian rocks, which are about thick, consist of Upper Proterozoic sericite and chlorite slate and schist that contain minor amounts of metavolcanic rocks, metaconglomerates, and quartzite. These rocks are intruded by metamorphosed gabbro, diabase, and felsic dikes and sills and granite intrusions. Overlying the Precambrian strata are up to of Upper Silurian to Lower Carboniferous consisting of interbedded sandstone, siltstone, slate, argillite, some conglomerate and rare limestone and dolomite. These strata are overlain by up to of Carboniferous to Permian limestone, often composed largely of crinoid plates, that is interbedded with slate, argillite and locally minor amounts of thick breccia, sandstone, and chert. The uppermost stratum consists of of Triassic clayey quartzose turbidites interbedded with black slate and siltstone.〔 A thin veneer of Cenozoic gravel, sand, clay and mud underlie the coastal plains of Wrangel Island. Late Neogene clay and gravel, which are only a few tens of meters thick, rest upon the eroded surface of the folded and faulted strata that comprise Wrangel Island. Indurated Pliocene mud and gravel, which are only a few meters thick, overlie the Late Neogene sediments. Sandy Pleistocene sediments occur as fluvial sediments along rivers and streams and as a very thin and patchy surficial layer of either colluvium or eluvium.〔 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「Wrangel Island」の詳細全文を読む スポンサード リンク
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