SPORT AND SCIENCE ON THE 
At Hsin-yin-tzi the valley bends northward 
again, and subsequently continues winding in a 
general north-easterly direction to its source. 
From this village the outcrops are entirely of granite, 
felsite and serpentine, no metamorphic rocks 
occurring, till, just before Hsi-wan-tzii is reached, 
an extensive outcrop of gneiss is encountered. 
Beyond Usi-wan-tzii (i.e. to the east) we found 
the mountains to be composed entirely of a dark 
grey-brown or purple-grey trachyte containing the 
characteristic white crystals of felspar. 
PART 6 
THE GEOLOGY OF THE COUNTRY TRAVERSED BY 
THE CHANG-SUI EXTENSION LINE, NortTuH- 
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 meta- 
morphic rocks, soft mica schists greatly pre- 
dominating. In places the schists show very 
marked stratification. 
Beyond this the valley widens out and the line 
no longer hugs the mountain side. Immense 
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