25 



CHAPTER II. 

 Ordovician. 



The most important geological features peculiar to Chinese land north of 

 Tsin-ling-shan are l. an extensive development of Ordovician limestone, and 2. 

 a total absence of the marine sediments ranging from Gotlandian up to Lower 

 carboniferous. These relations are at least cj^uite true of southern Manchuria 

 and northern Korea to which my personal observations extend, and appear 

 also to hold good in Shan-tung, according to the recent studies of I. 

 Hayasaka.^^ 



The Ordovician limestone, with rare intercalations of clastic sediments, ap- 

 pears almost always to pass insensibly downward to Upper Cambrian lime- 

 stone.^' Formerly this Ordovician limestone was included b\- Richthofen in 

 his " Kohlenkalkstein " lately in Shan-tung, it was called Tsi-nan limestone 

 by Willis and Blackweloer.*' The geologists of the Mining Bureau of 

 the Korean Government General included it in the " Great Limestone 

 Formation."'' 



In spite of its very extensive and thick development, the Ordovician 

 limestone is never richly fossiliferous ; when present, the fossils are usually 

 found scattered in certain laj-ers. 



The first convincing evidence of the Ordovician age of the said limestone 

 was brought forth by G. C. Crick''* of the liritish Museum on material from 

 south of Tsin-tchou-fu'' in Shan-tung, which according to" him contains 

 Actiuoci'1-as {^Ormuccras) aff tcnuifiluiii Hall 

 Goniocc7-as sp. 



1) H. Yabe: Is Lower Carboniferous really developed in Shantung? Journ. Geol. Soc. 

 Tokyo, vol. XXIIL, No. 274. igi6. pp. 129 — 137. 



2) Th. Lorenz: Beitrage zur Geologie und Palaeontologie von 0,-tasien, I. Qeologischsr 

 Teil. 1905. p. 14; F. Frixh: in Richthofen's China, vol. V., p. 14. igii. 



3) Richthofen: China, vol. IL, p. 



4) Researches in China, vol. L, p. no etc. 



5) Explanatory Catalogue of the Articles exhibited by the Mining Bureau, Korea. 1915. P. 3- 



6) G. C. Crick: Straight shelled Nautiloidea from North China. Geol. Mag. London. N.S., 

 dec. IV., vol. X., pp. 48t— 485. 1903. 



7) Wttllft 



