|
}} Cape Krusenstern National Monument and the colocated Cape Krusenstern Archeological District is a U.S. National Monument and a National Historic Landmark〔(NHL Documentation )〕 centered on Cape Krusenstern in northwestern Alaska. The national monument is one of fifteen new National Park Service units designated by the Alaska National Interest Lands Conservation Act (ANILCA) of 1980. It was initially declared a national monument under the authority of the Antiquities Act by President Jimmy Carter on December 1, 1978. Cape Krusenstern is primarily a coastal plain, containing large lagoons and rolling hills of limestone. The bluffs record thousands of years of change in the shorelines of the Chukchi Sea, as well as evidence of some 9,000 years of human habitation. The park's central features, 114 beach ridges at the eponymous cape, alternate between sandy and gravelly ridges and narrow ponds. Located entirely above the Arctic Circle in a region of permafrost, the monument's lands include typical thermokarst features. ==Description== Cape Krusenstern National Monument comprises the coast of the Chukchi Sea from the opening of the Hotham Inlet at the mouth of the Kobuk River, extending northwards along the coast to a point just short of Imikruk Lagoon. It extends inland toward the Kobuk Valley about , with a high point in the north at Kikmiksot Mountain () in the Mulgrave Hills and in the south at Mount Noak () in the Igichuk Hills. The coastline is marked by a series of lagoons separated from the sea by sandspits. The largest is the Krusenstern Lagoon at Cape Krusenstern.Others include the Kotlik Lagoon, Imik Lagoon and Aukulak Lagoon. The local bedrock is composed of limestone, dolomite, phyllite and chert from the Precambrian through Devonian times. The land was glaciated during the Illinoian glaciation, but was free of permanent ice during the Wisconsonian glaciation. Longshore currents have deposited beach ridges since the for 6,000 years. 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「Cape Krusenstern National Monument」の詳細全文を読む スポンサード リンク
|