230 RESEARCH IN CHINA. 
like other streams of the earlier stage, flowed southwestward; but as we 
have not traced this valley toward the northeast or southwest, we have 
no means of knowing its extent. Whatever its character may have been, 
the stream or streams which occupied it were diverted by such as originated 
on the Ning-shan fault-scarp and have now become the headwaters of 
the Hang-ho or tributaries of the Sha-ho. 
The Sha-ho above Fou-p'ing-hien.—I have already described in some 
detail the peculiar features of the canyon of the Sha-ho above Féu-p’ing- 
hién, and the relations of its northwestern and southwestern forks. Taken 
in connection with the direct but abandoned channel between Li-ytian-p’u 
and Foéu-p’ing-hién, they present an interesting case of diversion. To 
abbreviate the discussion, we may make use of the diagram in Fig. 58. 
x 
= 
Li-yuan-p’u 
Va 
5 Miles 

Fic. 58.—Map showing the course of the Sha-ho between Li-yiian-p’u and Féu-p’ing-hién, Chi-li; abcd 
being the present course and abd the former course of the western branch of the stream." 
Let ab represent the relatively wide aggraded valley about Li-ytian- 
p’u, and bd its abandoned section between Li-yiian-p’u and the junction 
of the Sha-ho. Let cd represent the canyon of the main fork of the Sha-ho, 
and bc the present course of the diverted southwest fork. Let the rock 
masses in which the channels are cut be essentially homogeneous, they 
being banded gneisses of flattish attitude. Then the problem is to discover 
conditions under which the stream abd may be diverted from its direct 
course as a tributary of the larger stream cd, and the canyons which now 
characterize the established channels developed. 
