GEOLOGIC STRUCTURE OF THE RIUKIU CURVE. J 3 



or amphibolite is more extensive, though it is only next to clay 

 slate and sandstone in distribution. The sandstone of the island 

 of Oshima is often highly siliceous, thus taking the appearance of 

 quartzite. A very compact, white or red quartzite occupies large 

 areas in the island, though restricted to the western part. Schalstein, 

 associated either with compact quartzite or with other r(3cks, is found 

 on the road form Toen to Xaon, Konase to Atetsu, Shodon to Nomi- 

 san, Akitoku to Osai, Setake to Kuji, Xaze to Aira, Yanyii to Akaoki, 

 Aira to Ikuzato, and south of Yamatohama; it is of very small extent 

 and is always destitute of fossils. Palaeozoic limestone is not rare; it 

 is found in thick layers between Imazato and Uken, and in small 

 lenticular masses in other rocks at Yui, Sokkö-zaki, Adachi and 

 Sukomo, and near Setake and Y^amma. The limestone is all cryst- 

 alline and without fossils. The following is an abstract of my field 

 note, showinof the ofeneral stratification of the Palaeozoic rocks : 



