CHAPTER XIII. 



GEOLOGICAL NOTES — BY A. DE C. SOWERBY. 



TT is with some hesitation that I set forth the following notes and remarks 

 •^ on the Geology of the country traversed by the Expedition. With but 

 a mere smattering of knowledge, picked up from text-books whilst on the 

 march, I realise my unfitness for the task of giving anything like a Geological 

 description of the Provinces passed through. Nevertheless it would seem to 

 be a pity were I to shelve even such meagre notes as I have been able to 

 gather about a country so little known. Eminent authorities on Geology have 

 travelled in North China, but the route taken by the present Expedition 

 seems to have been almost altogether through districts entirely new, so far 

 as this science is concerned. That part of Shansi west of T'ai-yiian Fu, and 

 the whole of Shensi north of the Wei Ho were out of Richthofen's path. This 

 interesting countrj' was missed too by the members of the Carnegie 

 Expedition 1903-4. It seems, however, to present features not found 

 elsewhere in China, a proper study of which would throw light upon many 

 problems in connection with the great loess deposits of North China. 



Throughout this Chapter I adopt the momenclature used by the authors 

 of " Research in China." This book (published by the Carnegie Institution 

 of Washington) deals with the results of the Carnegie Expedition already 

 mentioned, and in it, where dealing with this subject, Mr. Bailey Willis calls 

 the whole of the Yellow Aeolian deposits, so extensively found in all the 

 northern provinces, the Huang-fn formation. In Chinese, the word Huaiig-t'u 

 means literally " yellow earth." It refers to the true wind-deposited loess, as 

 well as to the fluvial deposits of the Chihli plain and elsewhere. Bailey Willis 

 took the name, which is a very happy one, from Huang-t'u-tsai, a village 

 situated about ten miles north of T'ai-yOan Fu. 



Another substance containing a large percentage of clay, and occurring 

 in many places with the loess, is called Sliao-t'u which means literally "baking 

 earth." It derives this name from the fact that it is suitable for mixing with 

 coal-dust to form a good burning substance. The mixture is either dried into 

 cakes, or is put on the kang-hre wet. It burns well, but slowly, forming a 

 very economical fuel. 



Throughout this Chapter I shall use the word Shao-t'tt in its real Chinese 

 sense, and the word Huang-t'u in the sense given to it by Bailey Willis. I 

 shall thus have three terms to use in connection with yellow deposits : — 



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