24 'liif ß~?I5 M * 7 7 ;• t-ti! Jt p^ 



V. Occurrence of Minerals. 



The Mineral Industry in the island of Sakhalin is still in its infancy. Before 

 the Russo-Japanese War, 1904-05, the only mines in work were the four coal-mines 

 near Alexandrofsk, said to have then given only about fifty thousand tons altogether 

 a year. The oil-fields at the Nabil lagoon and other places, mentioned in almost all 

 geographical notes connected with the island, remain still unopened. The Seru- 

 tonai coal-field was only worked for a time and theti abandoned. There are no 

 mines at all now in progress in the Japanese part. 



After the reannexation of Sakhalin by Japan, the island was visited by our 

 geologists, including myself, who belong or belonged to the Local Government. 

 Many coal-seams as well as some localities of gold-placers were discoverd, (see 

 Kawasaki's report). It is a wonder that the Russians in this " Prison Island " 

 did not care about the easily workable minerals, such as coal and placer-gold. 

 The island is very long but not broad ; and it is therefore not difficult to traverse 

 the island from one coast to another, or from the valley of large rivers towards 

 the sea. More discoveries of useful minerals will be made in the nearest future, and 

 will tend to the speedy opening of the land's interior by the wonderfully attractive 

 power of gold and other substances. 



Coals. In the Tertiaries, we find coal-seams sometimes attaining the thickness 

 of more than 3 meters. They are mostly found on the Naibuchi river, on the upper 

 course of the Uriu river, at several places between Tokombo and Shiranushi, in the 

 region of Serutonai, in the Tertiary regions on the west side of the Poronai river, 

 and on the main and branch courses of the Pilevo river, both in the tract of the 

 50th. Parallel ; and other places. In all these localities, there is a black-coloured 

 coal, while near Ochopokka, at Menabets, and on the west shore of the northern 

 basin of the Chipesani lake, there is observed only a bad coal of a dark-brown colour. 



Some of the coal-seams are nearly vertical. The age of the coals in the island 

 of Sakhalin is all Tertiary. The fossil leaves, as those we find at Poronai, Iku- 

 shumbets, Yiibari, and other coal-fields in Hokkaido, are only met with in the 

 fields of Naibuchi, Serutonai, and Khandasa. The resemblance with the coal of 

 Ikushumbets is observed in the samples from the Naibuchi river, the Khandasa 

 river, and several other places as Erumani near Söni on the west coast. 



Kawasaki classified the coal of the island of Sakhalin into two categories : 

 namely, one is more brilliant and more brittle and with more abundant volatile 

 matter than the other. 



