588 E. C. ABENDANON 



presently see, that the windings of the river can be explained in detail 

 from the geological structure of the country. 



From K'ui-chou-fu to I-ch'ang the Yang-tzi flows, for a distance 

 of 135 km. through the ranges of mountains bordering the Red 

 Basin of Ssi-ch'uan. Formerly I have already observed that the anti- 

 clines, which in the Red Basin strike almost NNE-SSW, are bent 

 round in the north and east toward the NE, ENE, and E. To 

 explain this, I assumed that the Red Basin had been forcibly pressed 

 up against the old mountain ranges of Kuen-lun and Tsin-ling-shan 

 trending in almost equatorial direction. The trends in these border 

 ranges of the Red Basin do not therefore conform to the normal in 

 the basin itself. 



From K'ui-chou-fu to I-ch'ang the Yang-tzi-kiang cuts the fol- 

 lowing formations : 



I. A granitic formation intersected by numerous dykes of granite, 

 diorite,^ and melaphyre, all of them striking almost N-S. 



' 2. Metamorphic schist, consisting of hornblende, chlorite, and 

 mica schists, alternating with layers of nearly pure quartz. 



3. Purplish-brown limestone with fossils, among which is a coiled 

 nautilus, which, according to Professor Freeh, of Breslau, marks 

 the Lower Silurian. The most striking are, however, the numerous 

 and very large casts of Orthoceratites. This is, I believe, the Cambro- 

 Ordovician Ki-sin-ling limestone of Blackwelder and Willis. 



4. Green shales of about 900 m. thickness; this the Middle Pale- 

 ozoic Sin-t'an shale of the afore-named gentlemen. 



5. The gorges-hmestone formation, 1,600 m. thick, called by the 

 two other explorers Wu-shan limestone. 



As, according to my researches, not only a part of the Wu-shan 

 gorge but all the gorges are built up of this formation, I consider the 

 name gorges-hmestone better than Wu-shan limestone. This forma- 

 tion is considered as belonging to the "Upper Carboniferous" by 

 said gentlemen. 



What Blackwelder comprises in the K'ui-chou series, has been 

 divided by me as follows: 



6. The reddish-brown sandstone and argillite formation, 300 m. 

 thick. 



I Under these names are comprised various kinds of aplitic and lamprophyric 

 " Ganggesteine " of granito-dioritic character. 



