WARPING AND FAULTING. 105 



with the mature erosion forms of the Ts'in-ling stage. And strictly accord- 

 ing to the later warping and faulting are the depths of the young canyons, 

 which pursue courses that are in some measure consequent on the slopes of 

 recent upwarps, but in general inconsequent to the older structure. The 

 present relations of altitudes and folds show that tectonic elevations of 

 Permo-Mesozoic age have given place to warped elevations of modern age ; 

 and the physiographic record makes it clear that one or more periods of 

 little or no elevation intervened. 



The present topographic cycle, which we may call either the Fon-ho or 

 the Yang-tz'i cycle, is characterized by the development of basins, warped 

 surfaces, fault-scarps, and great mountain ranges, and consequently also by 

 youthful erosion forms and extensive plains of aggradation. The scarp, 

 the canyon, and the alluvial fan are the marked accents of the cycle and 

 are the noted features of Asiatic topography. The warped surface that 

 bears the sculpture of a preceding cycle is also of general occurrence, but 

 has less often been noted. 



The map, plate 8, comprising the Chinese Empire and parts of adja- 

 cent regions, represents the distribution of elevated and depressed areas. 

 It is based on actual altitudes and is a rough hypsometric map; but it is not 

 accurate in that sense, because, on the one hand, the number of points whose 

 altitude is known is inadequate to accuracy, and on the other, effects of ero- 

 sion have been disregarded intentionally. The surface which the contours 

 represent constitutes the basins, slopes, ranges, and plateaus as they would 

 exist if a plain had been warped and dislocated and had not been eroded. 

 The map thus expresses the hypothesis that Asia was reduced to a general 

 peneplain and has since been warped in a manner to produce differences of 

 elevation exceeding 6,000 meters, 20,000 feet. In the preceding pages and 

 in volume i, part i, of this publication I have given the facts which indicate 

 that, in the districts we observed, the warping has taken place chiefly during 

 late Tertiary and Quaternary times. My present purpose is to extend the 

 inferences regarding modern mountain growths to regions that are genetic- 

 ally related to those which we saw. 



First, with reference to the region of the great alluvial plain of eastern 

 China, it is usually recognized that it is an area of depression, a downwarp 

 extending from northern Manchuria to Hu-nan and filled with alluvium 

 of the great rivers that debouch from the western and southern mountains. 

 We have shown that Shan-tung, the peninsula of the Eastern Mountains, 

 has since the episode of the early Tertiary faulting stood as a horst in the 

 sinking region, its margins being bent down but its interior not notably 

 raised in the process.* 



* Research in China, vol. I, part I, page 83. 



