6io E. C. ABENDANON 



made it clear enough there that I believe the relation to have been 

 exactly the contrary, namely: an older Kuen-lun range, against which 

 the almost meridionally directed recent folds of the Red Basin struck 

 — like the surf of the ocean beating against the firm land — thereby 

 causing them to rise and to bend round, and thus to assume, only 

 locally and incidentally, a trend in accordance with that of the sinial 

 system of folding. 



Another confirmation of my idea of the forcing-up of the Red 

 Basin folds, as I was able to observe it in the northeastern parts, I 

 find far to the westward, described in the following communication 

 by von Richthofen : 



The outermost southern branch of the sinial system, which to the south of 

 Kwang-yuen is still hidden under the formations of the Basin (see Fig. iiic) 

 now appears in ever mightier lines, striking at first WSW and then SW, and 

 forms (as beforesaid) the lofty northwestern wall of the plain of Tschong-tu-fu. 

 It here bears the name of San -mien -shan and Kiu-ting-shan.^ 



According to my opinion, the tension, which caused the Red 

 Basin to be folded and to be pressed up against the Kuen-lun, became 

 less in this westerly part, so that a basin fold still could be deviated 

 by the Kuen-lun from its normal direction but at the same time (the 

 fold) became flatter and vanished, instead of running high up against 

 the Kuen-lun mountains, as is the case in the eastern part. 



As concerns the signification of the Nan-t'ou antichne, we may 

 conclude from the foregoing: 



1. The crystalline schists are found to the west of the granite area 

 of Nan-t'ou. Originally they will also probably have occurred to the 

 east, but they are washed away, while sediments were deposited in a 

 basin forming itself to the westward. 



2. To the visibly oldest sediments belongs my lower Silurian brown 

 limestone of Sin-t'an, with its fossils, the Cambro-Ordovician Ki-sin- 

 ling limestone of Blackwelder and Willis. As we saw, this formation 

 does not extend as far to the east as the lower entrance of the Ox-liver 

 gorge. It does not seem to occur to the east of the Nan-t'ou anticline; 



I China, Vol. II, p. 639: "Der ausserste Siidzweig des sinischen Systems, welcher 

 nordlich von Kwang-jmen noch unter den Beckengebilden verschwindet (fig iiic) 

 hebt sich in seinen erst nach WSW, und dann nach SW gerichteten Streichen immer 

 machtiger hervor und bildet wie erwahnt, die erhabene Nordwestmauer der Ebene 

 von Tschong-tu-fu. Er fiihrt hier die Namen San-mien-shan und Kiu-ting-shan." 



