62 RESEARCH IN CHINA. 



steep rocky peaks. The series of red conglomerates underlain with red and green sand- 

 stone and shales is most probably pre-Carboniferous. I think it equivalent to the series 

 of red and green sandstone with middle Devonian fossils, which I have found in the Richt- 

 hofen range considerably further west on the section from the spring A-tza-k'ou to the 

 oasis Ch'ou-ma-er (pages 8-10) ; and also in a nearer section, in the canyon of Tsin-fo-ssi, 

 east of the meridian of Su chou. We shall meet a series of red and green sandstones and 

 shales, which underlie Carboniferous limestones with fossils and which form the northern 

 ridges of the range ; a similar red conglomerate was seen in the eastern part of the range 

 Mo-ma-shan. Hence it is more probable that all these similar formations of the Richt- 

 hofen range present shore and shallow water deposits of the same age, namely Devonian. 



Suess continues:* 



The To-lai'-shan in the meridian of Sou-tcheou is a somewhat narrow chain, but 

 like the Richthofen range, rises high above the snow-line, of which the altitude is 14,600 to 

 15,200 feet, 4,400 to 4,600 meters, in this region. It is distinguished from the preceding 

 range by an outcrop of gneiss along its southern border. The attitude of the beds, accord- 

 ing to the description of Obrutchov, is very peculiar: after having crossed, in coming 

 from the north, the intermontane belt of the deposits of Gobi, one observes intense folding 

 in a Paleozoic series, which is very thick. Locally the strike is northeast or north-northeast ; 

 then the strata resume the dominant west-northwest orientation, and finally the most 

 recent formations, the Carboniferous with beds of coal and Fusulina limestone, rest upon 

 the gneiss. The impression which the section gives in this locality is indeed not so much 

 that there is an overlap of the upper Carboniferous upon the gneiss as that there is an 

 overthrust toward the south, of the entire Paleozoic series upon the gneissic belt. 



Referring to another section of the To-lai'-shan, about 50 versts, 53 

 kilometers, west-northwest of the firstf Suess describes the continuation of 

 the folds which involve Devonian and later Paleozoic strata resting upon 

 raetaraorphic schists; and shows further that the gneissoid zone along the 

 southern margin, which has widened considerably, appears to be underlain 

 both north and south by upper Carboniferous coal-measures. This struc- 

 ture presents a problem of overlap or overthrust which remains indeter- 

 minate. 



The range of Alexander the Third rises south of the broad valley of To-lai-kouan, 

 which is entirely filled with debris ; it is formed, as may be seen from two transverse 

 sections taken a score of versts apart, of lower Paleozoic strata upturned and folded. 

 Toward the south these beds pass beneath a great syncline of Carboniferous strata, in 

 the midst of which the sandstones above the coal-measures are very extensively developed. 

 This synclinorium is so broad that the sandstones overlying the coal-measures constitute a 

 series of secondary arches, and the summits of the Ou-jd-chan, the most elevated part 

 of the chain, probably consist of them.$ 



Obrutchov himself sums up his description of the section of the range 

 of Alexander the Third by saying that "To-day's observations show that 



*La Face de la Terre, vol. in, p. 234. 

 f Ibid., bottom of page 235. 

 %Ibid., page 236. 



