12 RESEARCH IN CHINA. 



Globulitic and conglomeratic ("Wurmkalk") limestones. 

 Thin-bedded limestones, red and green. 

 Red shales. 



(Interruption.) 

 Crystalline limestone with nodules and layers of flint. 



(Interruption.) 



Alternation of crystalline, thin-bedded, limestone, including thin layers of flint, with 

 quartzite, epidote rock, red sandstone, etc. 



(Interruption.) 

 Gray crystalline limestone. 



This section does not present sufficient continuity to enable us to 

 identify the several formations precisely, but the sequence of three typical 

 groups of strata, cherty limestone, red shale, and characteristic Sinian 

 limestone, is apparent. The cherty limestones are evidently the same as 

 the Nan-k'ou terrane. 



With reference to the locality at which we observed the Ta-yang lime- 

 stone, the two sections cited from von Richthofen lie respectively, the 

 Nan-k'ou northeast, distant about 200 kilometers, and the Hsi-p'ing-shan 

 southwest, 80 kilometers. The Ta-yang locality thus lies between the two, 

 and all three occur in the foothills that bound the Great Plain on the west. 

 The greater part of the Nan-k'ou system in this northeast-southwest 

 trend is siliceous limestone, which, from its extent and unusual thickness, 

 is obviously a marine deposit. 



Both von Richthofen and Blackwelder have observed the older sedi- 

 mentary rocks of Liau-tung. After describing the fundamental gneiss 

 the former sums up his observations* by enumerating two groups, namely, 

 black quartzites and hornblende schists, which are intruded by granites 

 and greenstones and weather down to a rich soil and rolling landscape; 

 and the Ta-ku-shan series, consisting of firm, well-stratified quartzites of 

 yellowish and whitish tints, together with clay schists, mica schists, and 

 crystalline limestone. The schists and limestone occur in intimate but 

 indeterminate relations with the quartzites. The schists attain a thickness 

 of several thousand feet; the limestone is of limited or local occurrence 

 only. These strata are intruded by the Korea granite, and unconform- 

 ably overlain by a red cross-bedded sandstone with occasional conglomer- 

 atic layers, the Yung-ning sandstone. 



According to von Richthofen, the Yung-ning sandstone belongs to his 

 "Untersinisch."t Blackwelder,J on the other hand, regards it as a local 

 development of the Man-t'o shales, the red littoral deposit that marks the 



* China, vol. n, p. 106. 



f Ibid., vol. it, pp. 73 and 109. 



J Research in China vol. i, p. 95. 



