2 RESEARCH IN CHINA. 



The lithologic and structural characters of the T'ai-shan complex 

 are those of the Archean of the Lake Superior region of North America, 

 as defined by Van Hise. The rocks are chiefly metamorphic schists and 

 gneisses of indeterminate original character; associated with them is a 

 large proportion of metamorphosed igneous rocks and a very small pro- 

 portion of metamorphosed sediments; and the metamorphics are intruded 

 by granites, which are relatively young, though in large part probably 

 pre-Cambrian. 



The structure of the gneisses and schists is exceedingly intricate; it 

 is characterized by a universal schistosity; by a common banding; by com- 

 plex shearing, thinning, thickening, plication, and flow of bands; and such 

 intricate arrangement of the very variable petrographic facies of the schists 

 and gneisses as makes impossible any structural study by usual strati- 

 graphic methods. 



These lithologic and structural peculiarities of the T'ai-shan complex 

 serve to distinguish it unmistakably from the oldest pre-Cambrian sedi- 

 ments, the Wu-t'ai system, even though the latter are intensely metamor- 

 phosed. 



