MIDDLE YANG-TZI-KIANG GORGES 591 



with a slight relic of the sandstone formation. It is a strongly 

 compressed syncline, by reason of which compression a commence- 

 ment of dynamo-metamorphosis is observable, especially the reddish- 

 brown formation, recognizable by the far greater hardness of its 

 sandstone layers, and, besides that, by their becoming slaty on 

 account of the greater amount of mica they contain. 



In the following description of the different strata and their position 

 in the synchnal area of Wu-shan, I must neglect details and shall 

 merely describe the structure in general features. 



The Yang-tzi, which in the K'ui-chou-fu gorge flowed almost 

 vertically to the trend of the strata, downstream Tai-chi, transects 

 the reddish-brown and the slaty limestone formations which also dip 

 SSE, and, after a wedge-like compressed syncline, it strikes against 

 the 25° NNW-dipping hmb of the anticline south of the river. This 

 causes the river near K'ui-che-pan to bend from its ESE course into a 

 NE direction. In this part the layers are much disturbed, and a 

 relic of the sandstone formation is found among the slaty hmestones. 

 Near Tan-tia-wan the river has again gone too far north and has 

 abutted, in steeply SSE-dipping layers, against the southern limb of 

 the northern anticline. The river is now again forced to bend, and 

 flows in a WNW direction through the strata of the slaty limestone 

 formation, which, at first dipping faintly SSE, soon becomes almost 

 horizontal, and then again dips 50° NNW; and lasdy the river forces 

 its way into the reddish-brown formation, which also dips precipitously 

 north. Near Wu-shan the river has thus, for the second time after 

 Tai-chi, entered the northern limb of the southern anticline, which' 

 it has again transected in a gorge just below Wu-shan. 



Before describing this gorge, being another magnificent section 

 through a high mountain range, I will just discuss the profile of the 

 Ta-ning-ho, a tributary river, which flows into the Yang-tzi near Wu- 

 shan. Going in a NNW and N direction from Wu-shan, along very 

 hilly territory, in whose narrow synclinal valleys I only found relics 

 of the reddish-brown and of the slaty limestone formations, I reached 

 the place Ta-ch'ang or Kiu-shii-h-p'u on the Ta-ning-ho. This 

 swift narrow mountain stream I followed to its confluence with the 

 Yang-tzi'. Owing to the imposing gorges through which we passed, 

 and to the remarkable skill and proficiency in navigation with which 



