J 



been formed since the Wall was built. The city of San-yiian Hsien, situated 

 twenty miles north of Hsi-an Fu, has been cut in two, since it was built, by a 

 ravine 200 feet deep and over 200 feet wide. Again, in the Loess country of 

 North Shansi one may often notice the remains of a succession of old roads, 

 one below the other, along the side of a ravine. The ravine in these instances 

 marks the original trace of the road. This was washed away, so that it 

 became necessary to form a new road along the margin of the first. This in 

 turn became dangerous or unfit for use, owing to the continual falling-away of 

 great masses of loess, and again a new road had to be made. To-day a 

 yawning chasm remains, which has swallowed up each successive road, leaving 

 perhaps remnants of the last two or three. The whole process has taken 

 place within the memory of the older iuhabitants of the district, who can 

 testify to the facts. Places like this occur along the roads from T'ai-yuan Fu 

 to Shou-yang Hsien, and Hsin Chou. Of course the practice of the inhabitants, 

 who each winter root up or cut down every trace of vegetation, greatly 

 accelerates the denudation of the loess deposits ; but even taking this into 

 consideration, we must conclude that the rainfall, during the time when the 

 loess plain was forming, was far less than it is now. 



It may be suggested that these loess deposits were laid down at the bottom 

 of a lake, but there is no proof of this ; nor is there any reason to suppose 

 that it is a fluvial deposit such as the Chihli plains. The north Shensi basin 

 is open to the north, and there can be no doubt that the loess was originally 

 brought down from the Gobi Desert, of which the Ordos is but an arm. 



During our stay in Yu-lin Fu we had excellent opportunities of noting 

 how the wind, which we found to prevail from the north, carries southward 

 the material of which the Loess is composed. The inhabitants of North 

 China are familiar with terrible dust-storms, which sweep down from the Gobi 

 Desert at all times of the year. 



The Loess sometimes shows stratification. A good example of this 

 appears in the accompanying photograph (Plate 56)*, which was taken a 

 few miles west of the Chiao-ch'6ng Shan in Shansi. The strata occur in 

 alternate layers of brick-redj and light-coloured loess ; the former having 

 rather the constitution of Shao-fu. 



In many places we noticed, embedded in the loess, shells of a little snail 

 inhabiting the country at the present time ; whilst bones of the Mole-rat — 

 a rodent with an underground mode of life like the mole's — were also found. 

 No fossils of any kind were discovered in the Loess. 



• cf. Plate 55. 



I 129 



