220 RESEARCH IN CHINA. 
parts of the surface rise several thousand feet higher. The slope is steep, 
however, as compared, for instance, with that by which a similar old 
surface of erosion sinks beneath the plain near Tang-hién on the western 
side of the Great Plain in Chi-li, and there are no islands, the summits of 
buried hills. 
We did not see the embayment of the T’ai-yiian-fu basin west of 
Fén-chéu-fu, but crossed from the latter city southeastward to the point 
at which the Fén-ho escapes from the basin. We thus approached the 
northern end of the Ho-shan and traced the rise of the range from the 
relatively low hills that represent it near P’ing-yau-hién to the magnifi- 
cent scarp which characterizes it east of Ho-chéu. In this distant view 
the range reminded me of the Ki-chéu-shan. Like the latter, it seemed 
to originate in a warped surface, and to gain its greatest altitude in the 
development of a normal fault-scarp growing out of the warped surface. 
If the observations which we thus made on the northwestern and south- 
eastern sides may be trusted to apply equally to the east and west portions 
of the basins of T’ai-yiian-fu, this great depression represents an extensive 
downwarp, about the margins of which we see in general the remnants 
of the preceding topography, tilted toward the basin and dissected by the 
autogenous streams that had grown upon the warped surfaces. It is 
clear that such a downwarp must be filled by detritus from the adjacent 
hills, and that it is possible that its development may include an episode 
of lake history. Von Richthofen maps the loess of the basin in part as 
lake deposit, and places it among the depressions which have contained a 
salt lake. We were unable to make any investigations which might bear 
upon this point. 
The outlet of the Fon-ho from the basin of T’ai-yiian-fu has the look 
of a young river valley. Itis at the point of a sharp V between the foothills 
of the Ho-shan and those of the O-shan, which appear to be cut from sand- 
stones and shales of the Shan-si series. On the right bank of the river a 
conspicuous pagoda crowns a hill 500 feet, 150 meters, high and dominates 
the view. The plain slopes rapidly to the exit, like an alluvial cone of fine 
material, as though the upper valley were overfilled with detritus. The 
current of the river is swift. The rock gorge which the river enters is open, 
and the adjacent slopes are comparatively gentle as far as Liang-t’u-ch6n. 
The canyon of the Fon-ho, Ling-shi to P’ing-yang-ju (see map, Plate 
XXIII).—The comparatively open valley of the Fén-ho above Liang-t’u- 
chon is replaced as we approach Ling-shi by a canyon which deepens to 
about 400 feet, 120 meters, yet has a relatively wide, aggraded bottom. 
The canyon walls are not conspicuous, but are obviously steep in distinc- 
tion to the higher slopes, which widen out rapidly to the loess-covered 
