(i) Huang-t'u referring; to all deposits, whether Aeolian or fluvial. 



(2) Loesp, the pure seolian or sub-aerial deposit. 



(3) Shao-t'u, that substance, which resembles Loess, but contains a certain 



proportion of clay. 



The last usually contains more carbonate of lime than the second,* and 

 generally occurs at the bottom of the deep ravines in the Huang-fu formations. 

 So far as I have been able to gather, the lime nodules mentioned by various 

 writers occur in the Shao-Vii. The orig^in of the latter is difficult to determine.^ 

 but it is believed by some to be the result of decomposed Felspathic rock. 

 For want of any other name, I call the sedimentary beds of Shensi "the 

 Shensi formation," but the exact relationship between this and the Shansi 

 formation I cannot define, thousrh it certainly resembles the formation between 

 Chiao-ch'eng Shan and the Huang Ho. 



The country in the immediate vicinity of T'ai-yuan Fu, our startinp- 

 point, has been investigated by the members of the Carnegie Expedition, so 

 that I will commence drawing on my note book at the western bank of the 

 F^n Ho. In the preparation of this Chapter I have had frequent recourse to 

 "Research in China"; the line of march followed by the authors of that 

 work was from Pao- ting Fu in Chihli westward to Wu-t'ai Shan in Shansi; 

 thence southward through the middle of Shansi as far as T'ung-kuan Hsien, 

 just beyond its south-western border ; and from this point westward again in 

 exploration of the Ch'in-ling range and the country south of the Wei Ho in 

 Shensi. 



After continuing westward from T'ai-yiian Fu, in Shansi, to Yu-lin Fu, in 

 Northern Shensi, our own route lay in a direction roughly parallel to that of 

 the Carnegie Expedition, extending as it did from North to South down the 

 middle of Shensi. The Carnegie Expedition did not enter Kansu at all, and 

 the country we traversed seems to have been visited by no geologist. We 

 thus had the opportunity of seeing a mountainous country, namely the Chiao- 

 ch'eng Shan, dividing the F^n Ho from the Yellow River, the existence of 

 which seems to have been unsuspected by Richthofen, and only guessed at by 

 the members of the Carnegie Expedition. Both parties apparently confined 

 themselves to the valley of the F6n Ho, and formed their opinions of what 

 lay to the westward from what they saw of the small range of mountains 

 forming the north-western boundary of that valley. 



Richthofen speaks of the country between the Fdn Ho and the Yellow 



• The lows bas a luge pioportioD ofcUy, bttl dissFininaled and not separated as appeus to be the case with the SMao-t'ti. 

 t The CaOjCOj of ihe calcareous norules U p'f.V-pbh derived fr(>Di the upper beds by water action. 



116 



