98 RESEARCH IN CHINA. 



accessible deposits corresponding to the cycle of erosion. We are thus 

 restricted to physiographic evidence in seeking to date the epoch of faulting, 

 but, by comparing the effects of erosion with those accomplished elsewhere 

 since the middle Tertiary, we reach a probable conclusion that the time was 

 pre-Miocene. 



In the Ning-shan district of Chi'-li the relief due to faulting no longer 

 survives; indeed it has been reversed, limestone hills on the downthrow 

 rising 1,000 feet, 300 meters, above the surface of gneiss on the upthrow. 

 Hence we infer that the faulting may be somewhat older than that in Shan- 

 tung, and we place it in the earliest Tertiary. 



The faulted district of western Shan-tung and that of Ning-shan in 

 Chi-li are isolated occurrences in eastern Asia, so far as we now know, of 

 dislocations of early Tertiary age. Yet it is probable that they are not 

 singular, and anticipating somewhat the discussion of physiographic cycles 

 which follows, it is desirable to state in this connection the conclusion 

 reached by Suess, that the profound graben which is occupied by Lake Bai- 

 kal has existed since the close of the Tertiary period.* The evidence, which 

 consists of the survival of species of European Pliocene affinities in the lake, 

 is clearly assembled, and the age of the basin appears well established. The 

 depression is due to normal faults, which define the graben and which are 

 paralleled by others that give rise to the ranges of Trans-Baikalia. Attrib- 

 uting to the system the age determined for the lake basin, we recognize 

 in Trans-Baikalia a mountain group of late Tertiary date. 



It will be seen by reference to volume i, that the faults which charac- 

 terize the Ki-chou-shan, Ho-shan, Hua-shan, and Ts'in-ling-shan, all of 

 which are mountain ranges in Shan-si and Shen-si, China, are referred to a 

 Quaternary, probably middle and late Quaternary, date. Hence, taking 

 accpunt of the Chi-li, Shan-tung, Baikal, and Shan-si fault-systems, I con- 

 clude that normal faulting has been a feature of orogenic activity in Asia, 

 in one district or another, since early Tertiary time. 



Warping, that is, nearly vertical displacement of different parts of the 

 surface to unequal amounts and often in opposite directions without dislo- 

 cation, has been a general effect of diastrophism, especially during the later 

 Tertiary and Quaternary. And the displacements have been so conditioned 

 in time and place as to give rise to cycles of erosion, which can be distin- 

 guished in the plains, plateaus, ranges, and rivers of the continent. They 

 have been described in the physiographic study of the districts through 

 which we passed, as presented in volume i. There the surface is analyzed, 

 the development of streams is traced, and the interaction of diastrophic 



* La Face de la Terre, vol. in, p. 78. 



