a ready market. The poor people use the crude oil, which they purchase at 
half the price of the refined. There was no evidence of any other useful 
minerals in this district. The coal-beds however must be very extensive and 
valuable. @ 
Working southward from Yen-an Fu, the same horizontal sandstone bed- 
rock without faults is encountered, whilst the loess deposits are in the form of 
great plateaux, all uniform in height (Plate 22). These continue from Fu 
Chou to near Chung-pu Hsien, a distance of about seventy miles. South of 
the latter town the rock-beds, in the form of shale, rise considerably above 
their normal level, and the loess mantle is very much reduced in thickness, 
being in some places entirely denuded. Continuing southward, we found the 
shale strata very much contorted. Still further south again, at Yao Chou, we 
passed through a great outcrop of grey limestone, dipping sharply to the north. 
This seems to mark the southern boundary of the great North Shensi basin. 
From here the country gradually slopes down to the Hsi-an plain. The 
loess on the southern side of the limestone ridge is very thick, completely 
hiding the under-lying rock, and extending right over the plain. The country 
south of the Wei Ho was visited by the Carnegie Expedition, and a good 
account of its geology appears in the book subsequently published by the 
Carnegie Institution. I will not do more than draw attention to the variable 
temperature of the hot springs at Lin-t’ung Hsien. Bailey Willis found 
them to be 40° Centigrade (104° F.). Rockhill records their temperature at 
106° F. When we visited them they were at 108° F. whilst Dr. Jenkins, a 
resident missionary of Hsi-an Fu says that he has known them to reach 
112° F. In the mountains immediately south of Hsi-an Fu I found granite 
occuring at very low levels. Viewing the mountains southward from the 
top of the peak, about 5000 feet in altitude, I could make out nothing but 
igneous rock masses. 
Leaving this vicinity we will now follow the westward course of the main 
division of our Expedition on its way to Lan-chou Fu in Kansu, and for this 
we must return to Fu Chou. From that point westwards for about thirty-four 
miles the same loess plateaux as lie to the south and east were encountered. 
Then a stretch of very moist country: deep and clear streams in every valley 
and ravine: the hills clothed with luxuriant vegetation. Denudation must have 
been at one time very extensive, for not only is the loess low and well rounded- 
off, but the sandstone and shale substrata also show marked wearing. 
At Hai-shui-ssti, a peculiar column of sandstone—all that is left of a 
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