JIMBO : GEOLOGY OF JAPANESE SAKHALIN. 1/ 



just as on the south of Shiraraka, the beach-sand being broad especially on the 

 river-mouths ; from Poronaipo to Xayoro. the sea bottom is flat and sandy. The 

 rugged mountain-range along the sea-coast of the region of Poronaipo, stands in front 

 of low mountains of Tertiar>' rocks. This range is of such an andesite. as that 

 occupying a large area in the region of Makunkotan, and found also at many other 

 places on the coast-line from Dubki to Nayoro, where the exposures are mostly 

 Tertiary sediments. Liparite is founded only near Shiraraka. 



The east coast of Sakhalin has in general fewer rough places for observers 

 proceeding on foot than the west coast, although the region near Cape Shiretoko is 

 naturally an exception. 



The East Side of the Median Depression. 



Beginning our observation at the region of Korsakoff (original Ainu name, 

 " Kushunkotan ") on Aniwa bay ( K. Wada, p. 6), we find first of all a terrace 

 coast, extending about 50 km. from Tretiya Padji down to Chipesani, with charac- 

 teristic submarine shelves. The rocks exposed are mostly Tertiary, though at and 

 near Chipesani, there are Palaeozoic strata. Here lies the badly sheltered anchorage 

 of Korsakoff, the present seat of local government. To the south-east of Chipesani, 

 there is a low sandy coast with the interesting Busse lake, with oyster banks and 

 other marine products, and said to possess an opening with water 12 ft. in depth, 

 though this has not yet been confirmed by our observers. 



Further to the south, we have the steep rocky coast of the region of Palaeozoic 

 rocks, with granite at Cape Shiretoko and its immediate vicinity, where the cliffs are 

 very picturesque and attain about 100 meters in height. Here the principal barrier 

 to communication is the roughness of ground, while on the north the opening of the 

 Rutaka river prevents an easy passage from the sea into land. 



Leaving Shiretoko and passing over to the external sea (K. W'ada, p. 7 ), the 

 stretch of land from Shiretoko to Cape Toni (about 80 km, long) shows several dreary 

 sceneries of high and steep cliffs of Palaeozoic rocks, either descending directlj' into 

 the deep sea-water or with a narrow land below. There are many reefs in the sea- 

 water. Less rugged is the northern part of this region, which consists of Mesozoic 

 rocks without fossils so far discovered. 



Airop bay on the west side of Toni shows a narrow plain in front and 

 a hill behind, and there is the best road for ships running along. the east coast, 

 especially in the principal fishing season, when the northeast wind seldom sweeps 

 over the sea. 



The immediate vicinity of Tunnaicha is a broad sandy beach. 



