596 



E. C. ABENDANON 



the 45 km. long Wu-shan gorge, through layers, dipping rather steeply 

 N, of the upper levels of the gorges-limestone which show a turning of 

 the anticlinal axis toward W-E. 



To recapitulate we see that as far as the Wu-shan gorge exposes 

 the structure of the mountain range south and east of Wu-shan, this 

 range appears to be formed by three anticlines, closely pressed 

 together. Of these the anticline farthest upstream rises highest, for 

 in that we see the green slaty formation underlying the gorges-lime- 

 stone formation. (Fig. 5 gives a sketch of my conception of the 

 geological structure of this gorge.) The Yang-tzi has cut its course 



quite through the 

 northern two anti- 

 clines, and then 

 through part of the 

 northern limb of the 

 southernmost one. 



From the above it 

 will appear that my 

 ^ observations, which 

 were taken while 

 going upstream, at 

 the rate of 2^ km. a 



Fig. 5 



day, differ in many particulars from those of Willis, which were 

 taken during the so much swifter course downstream. 



The principal difference is, that Willis considers a great part of 

 the Wu-shan gorge to be formed of Ki-sin-ling limestone, while I 

 maintain that nothing but the gorges-limestone, Willis' Wu-shan 

 limestone, appears in that gorge. 



Willis writes: "Below Nan-mu-yiian the base of the Wu-shan 

 limestone is marked by the occurrence of black cherts and it may be 

 assumed that the Sin-t'an (middle Paleozoic) shale occurs in its 

 proper place below the limestone, but we did not see it."^ 



From what I have written above, it appears, that the thick Sin- 

 t'an shale formation was not observed by me either in that place, 

 although it would have been almost an impossibility to overlook it 

 (had it been there) going, as I did, so slowly upstream. Besides, in 



I Op. cit., Vol. I, Part i, pp. 286, 287. 



