64 RESEARCH IN CHINA. 



Devonian strata are known where the Kuen-lung converges in the 

 Mustagata, toward the Tien-shan, and have been identified in the southern 

 ranges of that great system, north of the Taklamakan desert. Farther to 

 the northeast, in Trans-Baikalia, they constitute the oldest fossiliferous 

 rocks known. 



We have thus traced the repeated outcrops of middle Paleozoic strata 

 from the province of Shen-si in central China, in longitude 106 east of 

 Greenwich, northwest and west to longitude 74. The terranes probably 

 comprise pre-Devonian Paleozoics, at least as far west as longitude 94, 

 but in the section last quoted from Bogdanovitch middle Devonian appears 

 to rest directly upon the crystallines. Nevertheless, in the present state of 

 geologic knowledge of these remote regions, it would be hazardous to assert 

 that earlier Paleozoic, even to Ordovician or Cambrian, is not represented. 

 Somewhat farther west, in the Zaravchan (Sarawschan) range, longitude 

 70, Romanovski collected Halysiles catenulatus. The middle Paleozoic 

 of eastern Turkestan is closely related to and connected with that of 

 Europe by way of the Urals, and also with North America by Siberia.* 



The line of observations which we have followed from Central China 

 pursues the course of one of the great mountain trends of Asia, between the 

 Gobi and the Tibetan masses. Paleozoic strata may probably be absent 

 over part of the latter, at least if the inference based on structural axes be 

 valid. Around its eastern end the ranges extend southward toward the 

 Malay peninsula, and in Burmah they are joined by the Himalaya trends.f 

 We may trace the occurrence of Middle Paleozoic rocks along this southern 

 route also. 



Devonian is known from several localities in southwestern Ssi'-ch'uan 

 and adjacent districts in Yun-nan, among the Paleozoic strata which form 

 the mountain ranges of western Tibet, bordering the Mesozoic red basin 

 on the west. Westward from Ja-chou-fu (latitude 30, longitude 103) , in 

 the vicinity of "Lin-tschin-shien," Loczy found the Jurassic itself thrown 

 into folds, resting unconformably on strata which he assigns in general 

 terms to Silurian, i. e., early Paleozoic. He refers to the rocks simply as 

 limestone, and makes the correlation without paleontologic evidence. % 

 Beneath these strata occur granite and diabase. A few miles further 

 west, between the Fu-yung-ho and the village of Hoani-pu (Hua-ling-pu) 

 he crossed the Ta-shian-ling, which is composed of granite and quartz 

 porphyry and flanked on both sides by coal-bearing Jurassic strata. On 

 the northeastern slope the supposed Silurian beds occur. The town of 



*De Lapparent: Trait6 de Geologic, 1906, vol. n, p. 864. 

 fSuess: La Face de la Terre, vol. in, map. 

 JReise des Grafen Szechenyi, vol. i, p. 677. 



