J. S, Lee—An Outline of Chinese Geology. 419 
As the result of the disappearance of inland waters, the atmosphere 
of northern and north-western China became arid. At the end of the 
Pliocene or the beginning of the Pleistocene time aeolian conditions 
prevailed. The decomposed rock-material was blown about and 
spread far and wide over hills and valleys. Thus the formation of 
the Loess began, and has continued down to the present day. It 
is uncertain whether there was a general lowering of temperature 
during this period in China! as in north-western Hurope and North 
America ; for even if the climate was severely cold, the aridity of the 
atmosphere could not have allowed the existence of large glaciers. 
The absence of a large mass of ice in Hastern Siberia to-day, in spite 
of the Arctic temperature, well illustrates such a case. 
Since the mid-Tertiary movement hypogene geological forces 
have by no means become dormant; for we clearly see that the 
Young Red Sandstone and even the river deposit in the lower Yang- 
tze Valley are generaliy tilted. According to Mr. V. K. Ting the 
Loess in the Ssue-hua-shan and other districts, south-western 
Chi-li, is affected by a basaltic igneous rock. Apart from such 
stratigraphical evidence there is to be noted another class of 
phenomena—phenomena belonging to the physiographical domain— 
which, when carefully analysed, would undoubtedly throw lght 
upon the problem of recent earth-movement in China. For the 
want of space, here we can only refer to one or two important 
- points. 
Let us follow for the moment the courses of the Hwang-ho and 
the Yang-tze-kiang. The fact that both of these rivers flow in their 
middle courses towards the central mountainous area, the Tsing- 
ling Range, is sufficiently significant to claim our consideration. 
If Pumpelly’s diagram ? illustrating the prehistoric course of the 
Hwang-ho be based on good authority, then the Hwang-ho must 
have travelled at one time through northern Shan-si and north- 
western Chi-l. The huge delta that spreadsin front of small streams 
from the mountains to the north-west of the Plain of Peking, as 
described by G. F. Wright,? appears to signify the previous existence 
of a powerful river, and therefore may be taken as a specific feature 
that tends to support Pumpelly’s hypothetical diagram. Along the 
northern foot of the Ta-hwa-shan the Loess is apparently affected 
by the Ta-hwa fault which is, without doubt, a continuation of the 
famous Wei-ho fault. It then seems highly probable that the 
southerly course of the middle Hwang-ho has been determined by 
an uprise in north-eastern Chi-li and the downthrow of the Shansian 
block against the Tsing-ling Range, owing to the continued develop- 
ment of the Ta-hwa-Weiho fault. The “‘ Universal Deluge” in 
northern China, before Emperor Yue (about 2700 B.c.) accomplished 
his great engineering feat at Long-menn (about long. 100° 10’ E 
1 Cf. Geikie, The Great Ice Age, p. 402. 
* Pumpelly, op. cit., pl. v, map xi. 
3 Quart. Journ. Geol. Soc., vol. lvii, p. 244. 
Of) 
