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 lOO 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 W^n-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 F6n 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'e-lan Chou a town about sixty 

 miles north-west of T'ai-yiian Fu, and again at Wu-ch'6ng a village half-way 

 between Yung-ning Chou and F^n-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'^ng 

 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 Sinian 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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