besides Pegmatite, Felspathic and Micaceous rocks, and Gneisses were plentiful 
in the valley-bottoms on either side of the pass. 
With my limited knowledge, it would be hopeless to attempt a full 
description of the complicated structural formation of the Chiao-ch’éng Shan 
district : the most I can do is to mention the names and the positions of the 
rocks which I noticed. So far as I could gather, these mountains, like those 
in the Ning-wu district, are formed by a great fold, the softer rocks of which 
have been denuded, thus laying bare the Plutonic rocks. The tops of the 
peaks and ridges are undoubtely of granite, which varies in colour from grey 
to pink, and in texture from a fine to a coarse grain. The summit of Mo-érh 
Shan (9,200 feet), the highest peak in the district, is in the form of a hugh cone 
of grey granite, slowly breaking up into large blocks—roughly cubical—many 
of which lie scattered down the mountain’s side. Slightly curved joints— 
very noticeable in our illustration (Plate 55)—cut across the summit, and 
appear to form an anticline. On the next highest peak Yiin-t’ing Shan, red 
granite appears, as well as the grey. To the north, the peaks and ridges seem 
to be composed of gneiss and other metamorphic rocks, with ribs of granite 
here and there. The valley-bottoms are strewn with boulders, and stones 
of all kinds of crystalline rock; the minerals quartz, mica, and felspar 
predominating. 
On descending the western slope of this great ridge, which divides the 
basin of the Fén Ho from the Yellow River, we soon reached again the beds 
of shale and sandstone. They present here features similar to those east of 
Chiao-ch’éng Shan. Huang-t'u is very widely distributed, and in many places 
hides all other formations by extending right down to the valley-bottoms. 
At a distance of about fifteen miles from the Chiao-ch’éng Shan range, we 
crossed another small divide, the summit of which was composed of shale 
protruding through the Huang-t’'u. Between here and the next pass—about 
twenty miles further west—lies the river valley, in which the town of Lin 
Hsien is situated. The valleys between these three divides run from north- 
east to south-west, eventually joining the Yellow River. 
The Lin Hsien valley is filled with vast deposits of Huang-t'u so that 
only at the ravine-bottoms is the substratum of sandstone exposed. 
One might consider the chain of mountains, which divides the Fén Ho 
from the Yellow River, as forming the eastern boundary of a vast flat basin. 
which takes in the whole of Northern Shensi, and the adjacent parts of Shansi, 
and Kansu. This basin is underlain by the Sinian Limestone, upon which 
lie Sandstone and Shale formations, which in turn are covered by a thick layer 
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