GEOLOGIC STRUCTURE OF THE RIUKIU CURVE. 



59 



In these rocks 

 there can not be 

 distinguished any 

 particular horizon 

 either by fossil 

 contents or by 

 petrographical 

 characters. The 

 limestones which 

 are found in Ajukö, 

 Shakokö, Reisuikö, 

 Yûra and between 

 8 a n c h ô r i and 

 Shinkögai, are 



mostly more than 

 10 ft. in thickness, 

 but at Yüra they 

 are only a few feet 

 thick. Lithotham- 

 nium rosenhergii 

 Martin predomi- 

 nates as in the 

 limestone of Ishi- 

 gaki - jima. I 



I. Kusshaku series, 

 a) Pecten etc. (Kyoryöho) 



y/y/yy-yvyy^ /yyyM:-y/,y/^//y.yy-y//yMyC^^ b) Jmpure limestone (Kyaryôho) 

 c) Ostrea (KyOryöho) 



II. Shinten series. 



i yy^>m',:yyy:,. lyy/'/y?- 



yyyyyyyy,yyy,.,.'/^ _ 



<^^' yyyyyy^yifyyyyy,77!T/. 



d) Ajukö limeston. 



III. Keibi series. 



Limestones near 



e) Sanchôri, in ({) Reisuikö, and (g) Shakökö 



h) Shells (east of Hattoj 

 V. Shinkyakutei series. 



i)Xenophoraetc- (Kôkwan), (j) Pecten (Kinkwaseki) 



V. Denryökö sérias. 



k) Yora limestone. 



1) Elchinodiscus etc. ) 



m) Pecten > Hatte 



n) p;chino<3iscus. > 



o) Pecten (near Keelung). 



VI. Gwaibokuzan series. 



p) ÏQra limestone. 



VII. Kankyaku series. 



q) Echinodiscus (Pachinâ). 



VIII. Intansliinai series. 



r) Macha etc (Daikökö-Iwözan). 



Fig. 10. — Profile of tlie Tertiary rocks on the northern side of 



their principal synclinal axis, with various limestone 



and coal beds and fossil horizons. 



found in the Tertiary rocks in several places in this northern portion 

 the following fossils, which were partly determined by W. Newton and 

 R. Holland* and partly by myself: 



* Newton and Holland, Notes on microscopic Sections of Limestones from Formosa. — 

 The Joiirn. Geol. Soc. Tokyo, Vol VII., No. 81, 1900. 



I collected peculiar large cone-shaped fossils from Sekiteigai and Shakôkô. Prof. Koto 

 sent them to Dr. R.B. Newton for determination, and has been recently informed that they 

 belong to Cellepora in Bryozoa. 



