GEOLOGY OF JAPAN 71 



mineral acids are distinctive, especially Kiisatsu, Kannawa and Nasu 

 in their alumina and iron content. Springs which are bitter, fen-uginous, 

 simple or earthy carbonated, etc. are also found in Japan, though 

 they are not of frequent occurrence. Many springs contain small 

 proportions of boric acid, iodine, bromine, lithium, manganese, and 

 other compounds. 



The quantity of radium emanations from springs in Japan appears 

 to be more closely connected with the geology than with the chemical 

 composition of the water, and springs of strong radio-activity are found 

 mostly ill granite regions. 



The mineral springs of strong radio-activity are as follows : 



Hot Spring Mache's units Cold Spring Mache's units 



Misasa 142.14 Masutomi 1425 



102.83 Takayama 281 



Seldgane 33.47 Ikeda 187 



Tochiomata 25.8G Arima 87 



Togatta 24.58 Hirukawa 60 



5. Minerals and Mineral Deposits. 



Minerals : — The number of mineral species hitherto known in 

 Jai)an amounts to 208, excluding those of organic origin. Minerals 

 or crystals characteristic of Japan aT-e radial concentric aggregations 

 of rhombohedra of arsenic ; magnificent crystals of stibnite ; large and 

 beautiful crystals of galena, zincblende, enargite, danburite and topaz ; 

 beautiful crystals of i)yrrhotite, axinite and columbite ; needle forms 

 or triangular crystals of chalcopyrite ; twinned crystal of quartz ; 

 unusually large crystals of augite, andalusite, glaucophane and pied- 

 montite ; xenotime and zircon in parallel growth ; zircon containing 

 some rare earths ; cordierite crystals occurring in lavas, etc. 



Mineral Deposits : — By far the greater part of our mineral 

 resources are found in the Tertiary terrain. Gold-quartz and cupri- 

 ferous pyrite-quartz veins are common in the Tertiary liparite or 

 andesite and their tuffs. In the Palaeozoic schists and clayslales occur 

 bedded cupriferous pyrite deposits which are of a great importance iti 

 Japan. Magnetite masses and hematite veins in granite, and galena- 

 blende masses or veins found respectively in the Palaeozoic limestone, 

 and Tertiary tuffs are also known to occur. Coal-seams in the 



