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The Aïr Mountains or Aïr Massif〔The diaresis over the i notes that it should be pronounced separately and not together with the a. Occasionally also spelled without it as Air or the Air of Niger.〕 (; Hausa: Eastern ''Azbin'', Western ''Abzin'') is a triangular massif, located in northern Niger, within the Sahara Desert. Part of the West Saharan montane xeric woodlands ecoregion, they rise to more than and extend over . Lying in the midst of desert north of the 17th parallel, the Aïr plateau, with an average altitude between , forms an island of Sahel climate which supports a wide variety of life, many pastoral and farming communities, and dramatic geological and archaeological sites. There are notable archaeological excavations in the region that illustrate the prehistoric past of this region. The endangered Painted Hunting Dog, ''Lycaon pictus'' once existed in this region, but may now be extirpated due to human population pressures in this region.〔C. Michael Hogan. 2009. (''Painted Hunting Dog: Lycaon pictus'', GlobalTwitcher.com, ed. N. Stromberg )〕 ==Geology== The Precambrian to Cenozoic Aïr Mountains consist of peralkaline granite intrusions which appear dark in colour (unusual since most granitic masses are light-toned in the field). In the Sahara Desert such mountains often stand out in stark relief as topographic heights amidst lowlands covered by sand.〔(Use of Remote Sensing in Basic Science Studies ), Section 17, NASA/Primary Author: Nicholas M. Short, Sr. (Site last updated: June 18, 2007).〕 The terrain consists of high plateau, mountain ranges, and broad, sandy valleys and seasonal wadis which once contained rivers. Areas of these deep, often intersecting, valleys also contain waterborne clay and silt deposits. Underground watercourses in some of these valleys continue to provide year round oasis and seasonal vegetation. The Aïr mountains themselves consist of nine almost circular massifs rising from a rocky plateau, bordered by the sand dunes and plain of the Ténéré Desert to the east. The massif is a plateau consisting of a sub-Cambrian age erosion surface on Precambrian metamorphic rocks, punctuated by a series of flat-topped, granite intrusion peaks, which include Mont Idoukal-n-Taghès (Niger's highest point at 2022 m),〔: incorrectly calls peak Mont Bagzane. Name of the peak is "Idoukal-n-Taghès", part of the plateau named "Bagzane". Also note, official and international sources believed Mont Greboun to be the highest peak as late as 2001.〕 Mont Tamgak (1988 m), Mont Greboun (1944 m),〔.〕 Adrar Bous, Fadei, Chirriet, Taghmert, Agueraguer, Takaloukouzet, and Goundai. The massif contains volcanic features including the extinct caldera of Arakao, Cenozoic lava flows of hawaiite to trachyte composition, volcanic cones, tuff rings and one of the largest ring dike systems in the world.〔Paul D. Lowman Jr. (VolcanoWorld: Air, Niger ). North Dakota and Oregon Space Grant Consortia, administered by the Department of Geosciences at Oregon State University.〕 At Izouzaoenehe, lie the marble Blue Mountains, and the lower Zagado valley is surrounded by white marble hills. Carboniferous sandstone and coal units in the Iullemmeden Basin just to the west of the massif contain uranium mineralisation sourced from the granites of the massif.〔(URANIUM GEOLOGY: NIGER, WEST AFRICA ), NWT Uranium Corp.〕 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「Aïr Mountains」の詳細全文を読む スポンサード リンク
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