19 



of Korea in connection of the National Exhibition of 1915. According to this 

 paper, the I'ahieozoic rocks of Korea are divisible into two main divisions, the 

 lower of which comprises those of the Cambrian and Ordovician ages. This 

 lower division is again sul3di\'ided in the following way : 

 Upper group. Great Limestone Formation : 



Upper part containing gastropods, cephalopods etc., characteristic 

 of Ordovician. 



Middle part intercalating oolitic limestone beds and intraforma- 



tional limestone conglomerate (Wurmkalk). 

 Lower part containing Middle Cambrian trilobites and brachiopods. 

 Lower group, Yotoku^* series : 



Composed of quartzites and clay slates, with some intercalation 

 of sandstone and limeston. Lower Cambrian. 

 In 1916, H. Ml'RAk.ami"-'' of the Geological Office of the South Manchurian 

 Railway Company made an important contribution to the geolog}' of the 

 southern part of Liau-tung peninsula, and proposed the following succession 

 of the Cambrian rocks there developed : 

 Carboniferous. 

 (Unconformity) 



Middle Cambrian : to'al thickness l ,200 m. 



Upper division D: Siliceous sandstone and siliceous slate in 



alternation. 

 Middle division : 



C : Upper part comprising platy limestone, with the intercalation 

 of nodular limestone. 



Lower part composed of reddish, purplish and greenish 

 slates, with Cry/yfozoon limestone. 



R ; Thin foliated slates, intercalating lenses or layers of oolitic 

 limestone ; trilobites and brachiopods are common. At the 

 top of this group lies a zone of reddish micaceous sandstone. 



Lower division A : A thick complex of platy, marly limestone, 



1) Y6toku = ^g, 



2) M. M JRAKA.MI : Report on the Geology of Ksvantoslui, Mancluiria (in Japanese) ('ffi'j'HI^ 



