JIMBo : GEOLOGY OF JAPANESE SAKHAUX. 25 



The formation of natural coke on the contact of the Serutonai coal with a 

 diabasic rock has been already mentioned. 



The good coals in sea-beach pebbles and sands on the west coast of Patience 

 bay indicate in parts the real presence of coal there in the land, but are in parts 

 nothing more than pieces fallen from coasting steamers. 



Gold-Placers. Tlie petrc^praphical characters as well as the irregularly fissured 

 appearance of the Palaeozoic rocks remind us of the features observed in the principal 

 gold-placers in Hokkaido. Thus I brought round an experienced gold digger during 

 my traverses in the region of the 50th. Parallel, and ascertained the existence of 

 placers there. In the same manner Katayama found placers at several places near 

 Cape Sliiretoko. also on the northwest of the Tunnaicha lake and in other districts. 



Sea-beach placers were obser\ed on the east and west coast of the boundary- 

 region, and also on the west coast of Aniwa bay. 



But none of the quartz-veinlets in the regions of Palaeozoic rocks and Crystalline 

 Schists, analyzed in the Ci\'il Administration, gave a good trace of gold. 



Limestone. The gray limestone in the Palaeozoic occurs at some places. 

 Among them that on the southeast coast of Aniwa bay is situated at a place, from 

 where it can be easily brought out by steamers. In the same region a saccharoidal 

 limestone of a white colour is found. 



Crystallized Minerals of scientific interest are not wanting in Sakhalin. Thus 

 on the west coast, we have in the cavities of the granitoid diabase at Shiranushi, as 

 well as at Ambets and vicinit}-. analcime. natrolite. and prehnite ; and in the 

 andesite near Ushtomanai on the same coast, hexagonal columns of white aragorute 

 trillings. There are some crj'stals of white calcite in -3R found near Wäre, prettj- 

 pseudomorphs of chalcedony after fluorite in the compact pyrite-veins through the 

 diabasic andesite of Söni near Sliiranushi. a white massive quartz with moulds of 

 prismatic barite crj'stals ( whose angles were measured by making casts) among the 

 pebbles found by Count KöZüI Otani near Xayoro on Patience bay. and a 

 pseudomorph of a dirtj' brownish-gray calcite after a double-ended pyramidal crystal. 

 The last pseudomorph is often more than 10 cm. in length, and resembles thinolite 

 in form, and shows rough striae parallel to the middle edges of the simple pyramid, 

 in which the pseudomorph apjjears. It is found in the Tertiar\' shale and its 

 marly nodules on the east and west coast near the 50th. Parallel, in the Tertiarj' shale 

 on the Xaibuchi river with Cythcrca sp.. also in the Tertiar>- sandstone with fossil 

 shells on the lower course of the Akhmametieff river, etc. KawaSAKI brought a 

 single incomplete specimen in the Tertiar>- marl from Ussu on the west coast. 



Tökjö, December, 1907. 



