214 RESEARCH IN CHINA. 
westerly courses of the older streams of the region, indicates that even the 
master stream has been diverted to its present channel. ‘The course which 
it once had was probably through the pass, Shi-ling, to the Fén-ho. 
The fifth loess basin is that of Hin-chéu. It may best be described 
as an oval, intermontane plain, of the Huang-t’u formation, about 25 
miles, 40 kilometers, long and 10 to 18 miles, 16 to 29 kilometers, across. 
On the southwest, northwest, and northeast, low ranges of gneiss, schist, 
and slate inclose it in an are of hills, through which are several broad 
passes. Across the southeastern side stretches the nearly straight scarp 
of the towering Ki-chéu-shan, a magnificent wall, 3,000 to 4,000 feet, 
goo to 1,200 meters, high. The plain of the basin is very fertile and densely 
populated, ninety villages being in sight from a commanding peak. While 
sharing with the other loess basins the common characteristic of being 
floored by the Huang-t’u formation, the Hin-chéu differs markedly in 
many respects from them. Its area, roughly computed at 350 square 
miles, 900 square kilometers, is more than twice that of the other four 
combined. Its plan is an irregular oval, unlike an erosion form, and longest 
from northeast to southwest; whereas the others resemble river valleys and 
are longer from northwest to southeast. From each of them a canyon has 
been cut southeastward, but from the Hin-chdéu basin the large river, the 
Hu-t’o-ho, has been diverted northeastward to the valley of a minor 
stream. Southeast of the Hin-chéu basin is the great fault-scarp of the 
Ki-chéu-shan, a unique feature in this region, though only the northeastern 
one of several analogous scarps. And where the Ki-chéu-shan sinks away 
there is a pass, the Shi-ling, which is widely covered by the Huang-t’u 
formation and leads to the still larger basin of T’ai-yiian-fu. 
These differences between the Hin-chéu and the four smaller basins 
find their explanation in the relative effects of two processes to which the 
basins owe their characters, namely, erosion and warping. In the smaller 
basins the effects of erosion are more apparent, and it is difficult to recog- 
nize the superimposed effects of warping. In the Hin-chéu basin warping 
and faulting have produced a form on which the features of erosion are 
subordinate details. 
This description of the northern loess basins has thus far been directed 
to bringing out the distribution of the Huang-t’u formation and the arrange- 
ment of streams. Another aspect of the region is the character of the relief, 
and I commend to the student of physiography the expressive contours 
sketched by Sargent. (Atlas sheets C I, C II, and B II.) 
Outside of the Huang-t’u formation, which has its own peculiar forms 
of slope and canyon, the relief on the older rocks seems, at first sight, to 
present two principal aspects: that carved from the Pre-Cambrian schists 
and slates, and that sculptured in the Sinian limestones. The hills which 
