SINO-MONGOLIAN FRONTIER 



masses of detritus, brought down from the moun- 

 tains to the north, are crossed by the track, and 

 they testify to the enormous amount of denu- 

 dation 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. 



PART 7 



The Geology of the Country from Yang- 

 kao TO K'uei-hua-ch'eng, North Shansi 



As already stated, Yang-kao is situated on the 

 eastern edge of the Ta-t'ung Fu plain. To the 

 north lies a great chain of tall rugged mountains. 

 These seem to be composed mainly of metamor- 

 phic rock, gneiss being the only rock we encoun- 

 tered on entering these mountains on our way 

 to K'uei-hua-ch'eng. 



273 T 



