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The Karoo ( ; from a Khoikhoi word, possibly ''garo'' "desert") is a semi-desert natural region of South Africa. There is no exact definition of what constitutes the Karoo, and therefore its extent is also not precisely defined. The Karoo is partly defined by its topography, geology, and climate — above all, its low rainfall, arid air, cloudless skies, and extremes of heat and cold.〔Potgieter, D.J. & du Plessis, T.C. (1972) ''Standard Encyclopaedia of Southern Africa''. Vol. 6. pp. 306-307. Nasou, Cape Town.〕〔''Reader’s Digest Illustrated Guide to Southern Africa''. (5th Ed. 1993). pp. 78-89. Reader’s Digest Association of South Africa Pty. Ltd., Cape Town.〕 The Karoo also hosted a well-preserved ecosystem hundreds of million years ago which is now represented by many fossils. The Karoo formed an almost impenetrable barrier to the interior from Cape Town, and the early adventurers, explorers, hunters and travelers on the way to the Highveld unanimously denounced it as a frightening place of great heat, great frosts, great floods and great droughts.〔Palmer, E. (1966) ''The Plains of Camdeboo''. p. 12-13, 120, 126, 140-146. Fontana/ Collins,London.〕 Today it is still a place of great heat and frosts, and an annual rainfall of between 50–250 mm, though on some of the mountains it can be 250–500 mm higher than on the plains.〔 However, underground water is found throughout the Karoo, which can be tapped by boreholes, making permanent settlements and sheep farming possible.〔〔 The xerophytic vegetation consists of aloes, mesembryanthemums, crassulas, euphorbias, stapelias, and desert ephemerals, spaced 50 cm or more apart,〔〔''The New Encyclopaedia Britannica''. Micropaedia, Vol. 6. (2007). p.750. Encyclopaedia Britannica Inc., Chicago.〕 and becoming very sparse going northwards into Bushmanland and, from there, into the Kalahari Desert. The driest region of the Karoo, however, is its southwestern corner, between the Great Escarpment and the Cederberg-Skurweberg mountain ranges, called the Tankwa Karoo, which receives only 75 mm of rain annually.〔 The eastern and north-eastern Karoo are often covered by large patches of grassland. The typical Karoo vegetation used to support large game, sometimes in vast herds.〔〔Conolly, D. (1992). ''Conolly’s Guide to Southern Africa''. (5th Ed.) pp. 106-117. Conolly Publishers, Scottburgh.〕 Today sheep thrive on the xerophytes, though each sheep requires about 4 hectares of grazing to sustain itself.〔 ==Divisions== The Karoo is sharply divided into the ''Great Karoo'' and the ''Little Karoo'' by the Swartberg Mountain Range, which runs east-west, parallel to the southern coastline, but is separated from the sea by another east-west range called the Outeniqua –Langeberg Mountains. The Great Karoo lies to the north of the Swartberg range; the Little Karoo is to the south of it. 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「karoo」の詳細全文を読む スポンサード リンク
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