

OCCURRENCES OF JURASSIC. 87 



far to the northwest, beyond which in Mongolia no deposits of similar age 

 occur.* Following the trend of the mountain ranges from Ta-tung-fu 

 southwest through Shan-si, we come upon the Jurassic in the eastern Ts'in- 

 ling-shanf whence it may be traced through various synclines westward 

 across Shen-si to the Red Basin of Ssi-ch'uan. The line thus followed 

 constitutes the northern limit beyond which neither Loczy nor Obrutchov 

 report any observations of Jurassic deposits. 



The formations of this period in China are of the continental type. 

 They consist chiefly of sandstones, with shale, generally red, more or less 

 associated with coal, devoid of marine fossils, but characterized by plants 

 which, north of Indo-China, do not contain Gondwana species, but are 

 frequently related to Russian Jurassic forms. 



I proceed to the enumeration of some characteristic occurrences. 



In Shan-tung, in the coal-basin of Wei-hien, are strata from which 

 Lorenz collected Jurassic plants.* 



In the eastern Ts'in-ling-shan, near Shan-chou in Shen-si, Loczy 

 observed a basin of Jurassic strata which rest on ancient metamorphic 

 schists. He says: 5 



Back of Shan-chou the valley is bounded by steep cliffs, in which the steeply up- 

 turned transgression of the basin deposits is dearly exposed. As is shown in fig. 30 a, 

 the conglomerate beds which, in a gently mrKnfd attitude, underlie Shan-chou, assume 

 a constantly steeper, almost vertical dip ; they are underlain by fine-grained dayey sand- 

 stones alternating with dark marrv fevers, and nnaflv there come in dark, bituminous, 

 thin-bedded marls, with thin sandstone layers. These last constitute the lowest strata 

 in the basin, and are much folded as a whole in a width of a kilometer. In the marl as 

 well as in the sandstones occur numerous carbonized fruits (carpoh'thns) which 



described as belonging to cycads or as coniferous fruits resembling tnrimm According to 

 him they resemble the fruits of Bairia or Gingko of the Jurassic of Siberia. 



The occurrence thus described by Loczy is peculiar, in that it Kes so 

 far in the heart of the Ts'in-ling-shan and the strata are more strikingly 

 folded than is common with those of like age. 



Some miles south of the above-described occurrence, between "Tse- 

 chuen" and ''Kiu-tze-kuan," Loczy crossed an extensive basin filled with 

 deposits which lie in horizontal attitude and consist of the local sediments 

 from the surrounding mountains. He speaks of them as Mesozoic, but 

 does not cite any evidence, and it would appear not improbable that they 

 are of later age. 



*Lczy: Rose des Gnfca Si&Jumji, rot. n. p. 799. 



trtii, voL n, p. 415. 



t Beitrage mr Geologic Skan-toag*, Heft L 



Reae des Gnfen Szeckeoji, TOt i, p. 415. if. yt *. 



