46 ART. 2— S. YOSHIWARA: 



probably a dyke throug-li the Pakeozoic, but are not disturbed. 

 Sometimes the Tertiary sandstone is deposited over the andésite. 

 The sandstone in two small regions, namely near Ohama-mura, and 

 on the north-east of Shikamnra, is that exposed after the erosi(jn of 

 the overlyirig reefs ; and shows a regular dip towards the south. 

 That exposed near Ohama-mura contains imperfect casts of fossil 

 leaves. Another exposure of limestone in \) has the same character 

 and same inclination (NoO° W, S AV 40°) as those in the other parts. 

 In the western portion of 15, there are also exposures of agglomerate- 

 tulf with intercalations of sandstone and shale, showing the strike 

 varying from X 40° W to X-S, and the dip nearly westAvard with 

 an an "-le 10°-25°. The beddino- of the rocks has not been modified 

 by the andésite, with which they are in direct contact in some places. 



The characteristics of the Tertiary of Ishigaki-jima consist of the 

 deposition of agglomerate- tuff near andésite masses, and of limestone 

 at some distance from the andésite ; the andésite showing no iniluence 

 upon the bedding of the other two rocks. Except on the western 

 side of the Yarabu peninsuhi, the various Tertiary sediments are all 

 regularly inclined southwards with the strike varying from N 50° W 

 to E-W. This direction of inclination is moreover general in the 

 Palœozoic sediments. There may perhaps have taken place a single 

 great folding, after the deposition of the Tertiary rocks and the con- 

 temporaneous eruption of andésite. The single limestone bed on the 

 fringe of the island noAV appears in small separate tracks always with 

 the same inclination. 



The Tcrtianj of Kohaiiia-jiiiia, which is found only in its south- 

 eastern part, consists chiefly of fine-grained brownish sandstone with 

 thin layers of conglomerate containing pebbles of Palaeozoic rocks ; 

 besides these there is a very small exposure o? LithotJuunniiim-lunestone, 

 like that found in Ishigaki-jima. I found also a thin coal-bed at the 



