Chapter XVIII: Part 6

THE GEOLOGY OF THE COUNTRY TRAVERSED BY THE CHANG-SUI EXTENSION LINE,
NORTH-WESTERN CHIHLI AND NORTH-EASTERN SHANSI

From near Kalgan to Tsai-kou-pu this railway line traverses obliquely the wide valley of the Yang Ho, crossing a great mass of detritus brought down from the north. After leaving Tsai-kou-pu it follows a tributary of the Yang Ho, called the Nan-yang Ho, and soon passes through a range of mountains composed entirely of metamorphic rocks, soft mica schists greatly predominating. In places the schists show very marked stratification.

Beyond this the valley widens out and the line no longer hugs the mountain side. Immense masses of detritus, brought down from the mountains to the north, are crossed by the track, and they testify to the enormous amount of denudation that is taking place here. An examination of the rocks shows that the mountains to the north are composed mainly of granite and gneiss. These conditions prevail as far as Yang-kao, the present terminus of the line.

No sedimentary rocks of any kind were noticed on this journey, except the massive limestone forming a tall range on the south side of the Yang Ho valley. Elsewhere on the lower slopes a considerable amount of loess was noticed.

The schists noticed near Tsai-kou-pu probably belong to the same formation as the Wu-tai series, or are equivalent to it, while the granite and gneiss beyond are doubtless equivalent to the T’ai-shan Complex.