(it) 8 Palssontologia Sinica Ser. B. 



STRATIGRAPHY 



COMPARISON OF THE ORDOVICIAN BEDS IN THE DIFFERENT 



LOCALITIES OF HUPEH. 



Although the Ordovician beds at the different localities in Hupeh have been 

 studided and the results published at various times by other geologists and by the 

 author, nevertheless they will also be briefly summarized here for convenience in com- 

 parison. In the first place we shall take the Ordovician strata in western Hupeh into 

 consideration, which region may be regarded as the type locality of Ordovician formations 

 in Hupeh province or even in Central China. 



I. Western Hupeh:' At Nant'ou on the Yangtze River above I-chang, and on 

 the Ta-ning-ho in Ki-sin-ling pass Willis and Blackwelder^ found that there is a very 

 thick massive limestone overlying the Nan-t'ou tillite and attaining a thickness of more 

 than 1,200 meters in the Nant'ou section. They called it the Ki-sin-ling hmestone 

 and held that it represented the Cambro-Ordovician period. On the uppermost part 

 of the Ki-sin-ling limestone, as described by them there are green calcareous shales 

 alternating with nodular limestone about 60 meters thick, which directly underlie the 

 Sint'an formation. In the spring of the year 1924, Prof. Lee carried on detailed strati- 

 graphical work on the geology of the Yangtze Gorges. He discovered that the so- 

 called Ki-sin-ling limestone not only comprises the rocks of Cambrian and Ordovician 

 periods, but also the entire Sinian system, the first period of the Palftozoic as proposed 

 by Prof. Grabau4. Prof. Lee suggested another group name "Niukan Group" for the 

 actual Cambro-Ordovician strata so well exposed in the Niukan Gorge instead of the 

 so-called Ki-sin-ling formation. According to Prof. Lee's proposal the Niukan Group 

 may also be, from the fossil fauna point of view, divided into the Shipai shale at the 



1. Messrs. Hsieh and I,iu had taken a geological trip to south-western Hupeh in April of 

 1925 (Bulletin of the Geological Survey of China, No. 9), and Mr. H. M. Meng to north-western Hupeh 

 in the automn of 1928 (Memoir of Institute of Geology, No. 8. National Research Institute of China). 

 According to their n;ports the Ordovician beds at these localities are quite similar to those of western 

 Hupeh and numerous Orlhoceras were also seen in the Neichiashan formation. Now we know that 

 the so-called "Pagoda stone" at Hupeh province includes the orthoceracone Nautilids which are not 

 only Orthoceras chinense Food, but also many other forms of different species or even of different 

 genera as well. It is unfortunate that they did not bring any specimen back. So we can not discuss 

 them here. 



2. Willis and Blackwelder: Research in China, Vol. I, pt. I, pp. 269-272. 



3. J. S. Lee: Geology of the Yangtze Gorge. Bulletin of the Geological Society of China, Vol. 

 Ill, No. 3-4- 



4. A. W. Grabau: The Sinian System. Bulletin of the Geological Society of China, Vol. 

 I, p. 44. 



