468 Reviews — Geological Survey of Yesso, Japan. 



containing brown lignite. Mr. Munroe places their thickness a 

 3000 feet, with reddish-brown sandstone at the base. What the 

 upper portion may be is not stated. 



The Coal-bearing rocks are mostly light grey shales, with a three- 

 foot bed of limestone. They are contorted, striking N. 50° E. 

 (magnetic). They seem to be Tertiary, judging from " fossil leaves in 

 the shales." A number of fossil shells found in the Horumui field 

 will probably fix the point. This is the third Coal-bearing group 

 (from above downwards). The coal is similar to that of the Eocky 

 Mountains, of about the period of the latest Cretaceous or earliest 

 Tertiary deposits. 



The Horumui Karafto System. — These bluish grey shales and con- 

 glomerates, like the rocks of the Toshibets system, strike nearly 

 north and south. They are 600 feet thick, seem to underlie the Coal 

 rocks, and are older looking than these, as if somewhat meta- 

 morphosed. The pebbles are of crystalline rocks, and are not seen 

 in the overlying beds. No fossils have been found in them. An old- 

 looking limestone, much cleaved and apparently metamorphosed, is 

 thought to have been folded [contorted] by a later action than that 

 which affected the Horumui Karafto system. 



The Toshibets Kuril System. — A syenite group, striking N.E.-S.W., 

 is supposed to have furnished the pebbles of the overlying rocks. 



From the disturbances of the above rocks it is inferred that the 

 strata of the island have been twice folded alternately about northerly 

 and north-easterly. 



The palfBontology of these rocks is a point reserved for determin- 

 ation of the fossils, there being no means of accomplishing this in Japan. 



The useful minerals noted are coal, ironsand, sulphur, lime, 

 stone, gold, rock-tar, mineral springs ; traces of silver, lead, zinc, 

 manganese, and copper. About half the Eeport is devoted to these. 



The Coal is a brightly shining brown coal, in six workable beds of 

 3 to 8 feet, probably of Tertiary age. 



A sample examined by Mr. Munroe contained — 



Moisture 3-8 



Volatile matter ... 89* 5 



Fixed Carbon ... 52-4 ) ^ , ,c- ^^ j j n ce -t 



Ash (fawn colour) 4-3 \ ^""^^ ^^'^^^^ ^""^ '^"^^' ^^"^ 



The magnetic ironsand on or near the coast has been apparently 

 derived from the volcanic rocks. Part of it smelts easily ; part with 

 difficulty, owing to the presence of titanium. It was formerly 

 worked to some extent. 



Sulphur occurs mostly within craters of inactive volcanos or on 

 close adjoining outer slopes. The mineral is traced to the volcanic 

 fumes. Its manufacture or refining consists simply in melting the 

 natural accumulation three times, and straining through thick canvas, 

 the production of one place being 16 tons in three months. Horses 

 could go all the way to the mines, and it is thought that melting the 

 sulphur upon the shore would be more advantageous than at its sites. 



The abundaat exhalations at Tarumai and Esan volcanos must 

 be rapidly adding to the deposits, but how rapidly there is no means 

 of judging. 



