86 RESEARCH IX CHINA. 



itact at the base and an overthrust above. The Triassic strata consist of 

 sandstones and fine-grained sandy shales, which contain several species of 

 Myophoria, as well as impressions of Encrinms liliiformis, together with 

 other well-preserved forms. The locality is in western Yun-nan, latitude 

 28, longitude 100 east. 



The Red Basin of Ssa-ch'uan was first explored by von Richthofen. but 

 his observations still remain unpublished. Loczy crossed the northwestern 

 margin only, yet his account affords the best available information.* It is 

 quoted in the section on the Jurassic. 



The occurrences which have been described for the Yang-tzl and Ssl- 

 ch'nan are those of strata south of the metamorphic district of the Han 

 valley, which borders the southern Ts'in-Kng-shan. In the vicinity of Shl- 

 ts'uan-hien, along the middle course of the Han, and in that part of south- 

 eastern Shen-si which hes between Hing-an-fu and Chon-p'ing-hien. the 

 expedition of 1903-04 observed certain schists, which appear to hold the 

 stratigraptnc position of the Kui-chou series and to have the mineralogical 

 character that metamorphic rocks derived from those sediments should 

 have. They have been described in volume i, chapter xrv. 



We observed these metamorphosed Permo-Mesozoic strata about Shi- 

 ts'uan-hien in latitude 33, longitude 108 30* east. The next occurrence 

 toward the west which may be aJgiiMl to this horizon is described by 

 Loczy ,"f and presents peculiar characters. It Bes north of Kuan-vuan-hien 

 and is involved in the folds of the Pakozoks near Chau-tien. The strata 

 overtie the typical Carboniferous limestone and consist of slaty limestones 



sheared day slates, which are reddish-brown in color and inclose large 

 blocks. Loczy suggests that they are of Silurian age and are 

 overthrust on the Carboniferous, and this may be the case. But it seems 

 quaUy probable that the beds are Permo-Mesozoic and differ from those of 

 the same age near Kuan-yuan-hien simply in degree of slatiness. If so, the 

 relations are similar to those which exist between the altered rocks north 

 of Cbon-p'mg-hien, Shen-si, and the unaltered beds south of that town. 

 The fnchiaioB of large Kmestooe blocks is not explained. They may be 



ites, or of autoclastic nature. 



JURA 



Jurassic strata occur extensively in central and southern China, and 

 also in northeastern China in the provinces of Shan-tung and Liau-tung. 

 The basin of Jurassic coal-bearing strata near Ta-tung-fu in northern Shan- 

 si, longitude 113 ffyfr t latitude 40, J is apparently an isolated occurrence 



I, PL 6*5. 



