River as a plateau of nearly horizontal coal-bearing strata; whilst Bailey 
Willis suspects that the rock below the Sinian Limestone, together with the 
Sinian Limestone itself, forms the mass of the mountains west of the small 
range already mentioned. Neither of these observers mentions the great 
divide of Igneous and Metamorphic rock, which extends in a more or less 
complete line from Ning-wu Fu, five days journey (about roo miles) north- 
west of T’ai-yiian Fu, to Yung-ning Chou, four days journey south-west. 
Having penetrated these mountains at five different points I can vouch for its 
existence. Professor Lyman of the Shansi University discovered Granite and 
Gneiss in the mountains west of Wén-shui Hsien, a town about fifty miles 
south-west of T’ai-yiian Fu. 
From my notes it will be seen that Richthofen was not altogether wrong 
when he discussed the country west of the Fén Ho as a plateau of horizontal 
coal-bearing strata. There are undoubtedly great stretches of country marked 
by beds of this nature; but on the other hand there are large areas where, 
but for the Loess, the Sinian Limestone would form the surface. I have found 
this to be the case in the mountains west of K’é-lan Chou a town about sixty 
miles north-west of T’ai-yiian Fu, and again at Wu-ch’éng a village half-way 
between Yung-ning Chou and Fén-chou Fu. It also forms certain high peaks 
situated physiographically between the Shansi formation and the pre-Cambrian 
rocks in the Ning-wu district. Of course the outcrops of Pre-Cambrian 
(Igneous and Metamorphic) rock, already referred to, form a large area. 
The folding and vertical dips mentioned by Bailey Willis occur, as far as 
I can make out, only in the small range—not more than twenty miles wide— 
which extends from north-east to south-west along the north-western edge of 
the T’ai-yiian Fu plain. Westwards from this range till the Chiao-ch’éng 
Shan are reached the strata are horizontal. Further north, as the Ning-wu 
district is approached, these strata are arranged in a series of ridges having a 
north-east to south-west trend and formed by dip-slopes on the south-eastern 
and scarps on the north-western side. The dip-slopes vary generally from 30° 
to 80°, some being almost perpendicular. As already stated, between these 
ridges of Shansi formation and the great outcrop of pre-Cambrian rock, occur 
very high and precipitous ridges of Siniaa limestone. These form very pointed 
peaks, varying in altitude from 7,000 to 8000 feet above the sea-level. Their 
dips slope to the south-east at angles of from 45° to 60°, becoming almost 
perpendicular as the crests of the ridges are reached. The escarpments are 
due, doubtless, to erosion on the eastern side of an immense fold; the softer 
rocks on the anti-cline of this fold have been carried away by denudation, 
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