234 RESEARCH IN CHINA. 
the Hu-t’o-ho did once follow this course to the Fén-ho, but the wide 
valley which leads across the Shi-ling and down past Huang-t’u-chai is 
a feature which is clearly stamped with the characters of a much larger 
stream than any that now occupies it, either north or south of the pass. 
The elevation of the pass is of later date, not only than the erosion of 
the wide, mature valley, but also than the deposition of the Huang-t’u 
within that valley, for, in the basin of Huang-t’u-chai, the formation of 
that name is evenly stratified, like a deposit laid down in quiet water, 
up to an elevation of 3,300 feet, 1,050 meters; that is, 600 feet, 180 meters, 
above T’ai-ytian-fu. It is not possible that any water surface could have 
covered the plain at this level. Furthermore, the moderate activities of 
the intermittent streams, which now flow northward and southward from 
the Shi-ling, are sufficient to deeply trench the Huang-t’u formation. 
The growth of autogenous canyons within the formation is energetic; 
and even the wind is engaged in scouring away, rather than in depositing, 
the prevailing loess. There is no agency of wind or water which seems 
capable of spreading the Huang-t’u over the pass and depositing it as a 
finely stratified mass in the basin of Huang-t’u-chai, at its present altitude. 
Hence it is inferred that, through upwarping, the Shi-ling has developed 
the character of a divide, which it now possesses. 
Though based on independent evidence, the inferred upwarp is in 
agreement with the great elevation of the Ki-chéu-shan. The fault-scarp, 
which marks that range, ends northeast of the Shi-ling, and the warped 
surface of the mountain face extends southwest, not only to, but beyond, 
the pass. 
We thus have good reason to regard the Shi-ling as an elevated river 
valley, and, by a reasonable interpretation of relations, as the former 
river valley of the Hu-t’o-ho. 
The diversion of the Hu-t’o-ho from the Hin-chéu basin eastward 
was a direct consequence of the closing of the Shi-ling outlet. Whether 
a lake formed in the basin and overflowed at the lowest col, or a tributary 
of the river at Tung-yti captured the sluggish Hu-t’o-ho, we do not know; 
but either process is likely to have occurred under the conditions, and 
either suffices to explain the diversion. 
History of the Huang-ho.—Of China’s great rivers the Huang-ho is 
the second, and its history involves the interpretation of the events of 
at least the whole of the Pleistocene period and probably some part of 
the Tertiary. I do not propose to offer, on the basis of our slight obser- 
vations, an elucidation of the story of the river, which has probably had 
a complex development, but I wish, in connection with this chapter on 
the development of streams, to point out some of the characteristics that 
