24 



ART. 2 -S. YOSHIVYARA: 



The l*alaeozoic Oll the north-east of O yama is ehiefly clay slate. 

 In the eastern part of this region, a Palaeozoic sandstone is pierced by 

 a p«3rphyrite dyke with a NE strike. 



Yoron-jiiiiii. 'rtioiiii'h r ha\^e not visited this island, I am informed 

 that it is N'l'i-y low and plateau-like, consisting mainly of raised 

 (•oral reefs. As judged from a collection of rocks, there are in the 

 interior limited exposures of Palaeozoics, such as pyroxenite, sandstone 

 und limestone. 



Kihaiga-sliinui. This small island with a coast line of about 20 

 miles lies far to tlie east of Oshima and Tokuno-shima. The lono;itu- 

 dinal axis runs NE to SW, parallel to a line joining Oshima with 

 Yoron-jima. The interior is a flat table-land, with a maximum 

 height of 684 ft. above the sea-level. The coast is cliffy and fringed 

 witli recent coral reefs. Tlie island consists of raised coral reefs with 

 a foundîition of Tertiary rocks which are exposed only in a cliff' near 

 the sea coast (Fig. 1). The Tertiary rocks on the eastern coast, traceable 



Fig. 1.^ — .\ view of Kiifaiga-shima, as seen from the south-east. 



from Somachi to Ivamikatetsu, are chiefly bluish sandy shale, often 

 with intervening layers of marls and loose brownish sandstones and 

 very rarely with thin pumice beds. The sandy shale on the road 

 from Keraji io Urabaru shows a strike N20°W or N — S, and dip NE 

 or E with an angle of 35°. In the western part of the island, there 

 is found a marly sandstone, sometimes alternating with loose bluish 

 sandstone, and always dipping due west 5°. 



