PHYSIOGRAPHY OF SOUTHERN SHEN-SI. 321 
spond to the Pei-t’ai stage as exhibited in the Wu-t’ai-shan, the oldest 
features present being those of a mature topography, which more closely 
resembles the T’ang-hién stage of northern China, yet is presumably 
younger. No epoch of aggradation such as the Hin-chdéu stage is distin- 
guishable, the Huang-t’u being almost unknown south of the Wei valley, 
but in South China as well as in North, the epoch of recent uplift, the 
F6n-ho stage, is represented by great heights and correspondingly profound 
canyons. 
DESCRIPTION OF FEATURES ALONG THE ROUTE. 
Range of the Ta-hua-shan.—Entering the wide valley of the Wei-ho, 
we followed the base of the Ta-hua-shan from a point about 10 miles, 
16 kilometers, west of Tung-kuan-t’ing to its western end at Lin-tung. 
In the vicinity of Hua-yin-miau, where it apparently reaches its greatest 
altitude, the range rises abruptly to about 4,000 feet, 1,200 meters, above 
the plain (Fig. A, Plate XXI). It appears to consist chiefly of homo- 
geneous granite, which is sheared by major joint-planes approximately in 
east-west and north-south directions. The face is composed of stupendous 
precipices, one of which exhibits a smooth plane, probably 2,500 feet in 
height, at a slope of 70°. The summits are in some instances broad-topped, 
but in general acute, and the face is interrupted by canyons, which narrow 
in about 300 feet, 90 meters, above the plain and include a very narrow 
ravine in their bottoms. Toward the west the bold character due to 
vertical jointing gives way to more nearly pyramidal forms, apparently 
because the vertical joints pass gradually into a gentler attitude and 
finally become horizontal. In Fig. B, Plate X XI, the aspect of the west- 
ern end of the range, where it presents a much gentler slope than near 
Hua-yin-miau, is shown. The photograph exhibits the lower summits, 
which are truncated by the even slope of the fault-scarp, and the terraced 
deposit of loess that rises from the plain to a height of 300 or 4oo feet, 
about 100 meters. While we made no study of the range sufficient 
to justify more than general inferences, the facts indicate that the upper 
surfaces present a mature topography, and that the valleys in the dissected 
fault-scarp record the progress of uplift in their wider upper portions and 
in the narrow lower ravines, 300 feet, 90 meters, deep. The loess which 
lies upon the lower part of the slope has been described as possibly a wind- 
blown drift or as a portion of the valley plain carried up with the uplifted 
rock mass. 
Front of the Ts’in-ling-shan.—The northern front of the Ts’in-ling-shan, 
like that of the Hua-shan, varies in steepness. If it be anywhere as pre- 
cipitous as that of the Hua-shan near Hua-yin-miau, it is so south of 
