WU MOUNTAINS

WadeGiles romanization and Pinyin Wu Shan mountain complex on the borders of Hupeh, Szechwan, and Kweichow provinces, China. They are often referred to by Western writers as the Gorge Mountains, owing to the fact that the Yangtze River cuts its way through the area from the Szechwan Basin into the central Yangtze Basin, below I-ch'ang, through a series of deep and impressive gorges. The area is one of great complexity, being a zone of contact between the southeastern extremity of the Ta-pa Mountains, which have a predominant northwest to southeast alignment, and the plateau of northeastern Kweichow. The mountains are predominantly formed of ancient limestones, and it is probable that they were folded in more or less their present major structures in Jurassic times (208 to 144 million years ago). They have since been worn down by erosion to a nearly flat plain and then deeply dissected by the river system of the area, which cuts across the main structural lines. The thinly populated area remained a remote border country occupied by its aboriginal inhabitants until the Sung dynasty (AD 9601279). Even today cultivation is restricted to a few river valleys. The area is warm and wet and has a heavy forest cover. It produces timber, tung oil, tallowseed oil, lacquer, and other forest products. Communications, however, are very poor, apart from the river traffic. The mountains mostly average about 5,000 ft (1,500 m) in height, but individual peaks, particularly in the highest section to the north of the Yangtze Gorges, are considerably higherMount Ying-t'iao reaching 9,700 ft and Mount Chen-chu 9,518 ft. It is the ruggedness of the terrain, however, rather than sheer altitude that makes the Wu Mountains such a formidable barrier to communications, and the only highway through the area, connecting Wan-hsien (Szechwan) with Pa-tung (Hupeh), has to make a lengthy detour south of the main section of the ranges.