MIDDLE VANG-TZi'-KIANG GORGES 613 



Of all the existing theories those of antecedent and regressed or 

 beheaded rivers seem the most probable to me. Even in a developed 

 and grand river system as that of the Yang-tzi-kiang it seems quite 

 possible that both factors combined to produce such a system. 



When we look at the map of China, we are impressed by the 

 fact that the whole basin of the Upper and Middle Yang-tzi finds 

 an outlet through the most northerly area which borders, to the south, 

 the high dividing mountain range of north and south China. It 

 readily appears to us that whilst the Kuen-lun is the divide between 

 the Upper Yang-tzi and the Upper Hwang-ho, its eastern prolonga- 

 tion, the Tsin-lin-shan, remains the divide of a southerly developed 

 Yang-tzi system and a northerly developed Hwang-ho system. Thus, 

 in very general features, facts can be understood by a glance at the 

 map. 



But to return to the Middle Yang-tzi itself. We must first of all 

 bear in mind that the anticlines of the Red Basin, and with them, of 

 course, its entire area decline from N to S. This fact must be inferred 

 from the observations that in consequence of an intensive erosion the 

 anticlines in the northern parts of the Red Basin have been weathered 

 away to a thickness of at least 2,500 m. down the gorges-limestone, 

 which now still rises in mountains of 1,500 m. and more. These arch 

 cores of limestone are only to half their height concealed under anti- 

 clinal limbs of the younger formations. More to the south the Hme- 

 stone cores have lowered to the level of the Yang-tzi and the cores of 

 the sandstone formation, lying over the limestone, rise to anticlinal 

 ridges of some 300 m,, whilst there the overlying mighty K'ui-chou 

 formation has been washed away and has only remained in place in 

 the synclinal areas, where it is dissected by numerous narrow cross 

 and length valleys. At last, south of Ki-kiang, a place some 100 km. 

 in right line south of Chung-king, I encountered an anticline which 

 up to the height of 500 m. still consisted of the youngest or K'ui-chou 

 formation, the sandstone formation there being very much lower than 

 it is in the country of Chung-king. 



the antecedent theory, to which I shall also appeal, seems to him very improbable. 

 Kniep speaks of a peneplain between Wan-hien and I-ch'ang, where the Ta-kiang 

 (a local name for this part of the Yang-tzi) should have taken its meandering course 

 without close connection to the rock structure. 



