Page:Mongolia, the Tangut country, and the solitudes of northern Tibet vol 1 (1876).djvu/331

, gneiss, micaceous sandstone, and, the later volcanic formations; on the summit of Mount Bugutui the rocks are partly of quartzose conglomerate. Excellent coal-beds have been opened in the Ala-shan range.

The borders of the mountains of Ala-shan nearest to the plains are only covered with grass and small rare underwood, but at a height of about 7,500 feet on the western slopes there are forests consisting of spruce interspersed with poplar and willow. On the eastern side the forests probably begin lower down, but the prevailing trees even here are small poplars, with a sprinkling of white birch, pine, and arborescent juniper. The thick underwood of these forests is chiefly composed of spiræa and hazel, and in the upper zone of prickly Caragana jubata, called by the Mongols 'camel's tail;' the highest parts of the mountains are covered with alpine pastures. Formerly a good number of Mongols lived in these mountains, and three temples were erected there, but these have been destroyed by the Dungans.

The ornithological fauna of the Ala-shan range, contrary to our expectations, was very poor, chiefly owing, in my opinion, to the want of water. On the occasion of our first visit the season was the middle of autumn, and a large number of birds had flown south, but in the summer of 1873 we found a similar scarcity of birds here.