fj? RESEARCH IN CHINA. 
In transforming this comparison of forms into an estimate of relative 
age (and that is the object), we deal with the uncertain factors of rates 
of corrasion, as affected by slope and volume of the corrading streams. 
As regards slope, the differences are probably not notable, since in both 
regions gullies were initiated on steep scarps, and in growing to the dimen- 
sions of brooks and rivers they passed through the successive phases of 
profile determined on similar rock masses. The volume of the corrading 
streams is, however, a function of climate, and the possible differences 
between Shan-tung and the Great Basin may not be estimated with 
precision, except so far as similar surficial deposits have resulted from 
similar conditions. In both provinces, during the Quaternary, aggra- 
dation has prevailed over transportation, in the major valleys, to a remark- 
able degree. During that part of the Tertiary which followed the uplift 
of the Basin Ranges, a variable but relatively moist climate prevailed in 
the Great Basin, and the same is presumably true of Shan-tung, a moun- 
tainous district, which then, as now, was near the coast. These suggestions 
lead to the view that the two regions have not been under radically different 
climatic conditions; but so far as they have differed, the circumstances 
have been more favorable to erosion in Shan-tung than in the Great Basin. 
We thus reach a correction which should be applied to reduce any differ- 
ence of age between the topographic features we are comparing. 
Nevertheless, the contrast between the continuous ridges of the 
Great Basin and the separated mountains of Shan-tung is so great that 
climatic differences do not suffice to explain the greater effects of erosion 
in the latter over the former. Longer time, even much longer time, seems 
necessary. 
Faulting in the Great Basin region has been a persistent process, 
begun in the early Tertiary and continued to the present time. The major 
dislocations affect Eocene and Miocene strata (Esmeralda, Truckee) and 
Tertiary volcanics, and are assigned to the Pliocene. In comparison 
with these movements the older faulting of Shan-tung may have been 
completed before middle Tertiary time; it probably occurred during the 
Eocene. 
This inference is sustained by similar comparisons of the Shan-tung 
features with other fault-scarps. The western face of the Livingston 
Range, Montana, is a fault-scarp of Miocene or possibly Pliocene date,* 
which, though severely glaciated, is still far more nearly continuous and 
therefore probably decidedly younger than the faults of Shan-tung. In 

* Stratigraphy and Structure, Lewis and Livingston Ranges, Montana. B. Willis. Bull. Geol. Soc, 
America, vol. XIII, p. 344. 
