^letallogeny of the Japanose Tslantls. 15 



ore-bringers, and has Kosaka as its largest and most important 

 mine. The ore-deposits fonnd in this province are chiefly 

 replacements, bearing the so-called "black sulphide ore"; but 

 there are also famous veins of various other kinds. It is a 

 characteristic of this province that abundant sulphide minerals are 

 always present in the ores. The presence of this character may be 

 •due to the strong acidity, or high fusing point of the ore-bringer. 

 Even where andésite is the ore-bringer, the emanations emitted 

 from the rocks must have been at a high temperature, and thus 

 andésite itself was changed into propylite. Such a high tem- 

 perature compels the formation of sulphide minerals, which belong 

 to the liigher order of petrification of emanations; in other words, 

 sulphides were formed only in a temperature higher than that in 

 which gold, quartz and calcite (all common minerals in the 

 Satsuma Province) must be formed. 



The deposits in the Kosaka Province belong to the younger 

 veins, formed in the later period of the Tertiary or the earlier part 

 of the Diluvium. They are most frequent in the Tertiary sediments 

 or in the ore-bringer itself, forming replacements or veins. The 

 province includes nearly the whole of the inner zone of North 

 Japan, as well as isolated points in the inner zones of South Japan 

 and the Ryûkyû Arc. The deposits in the Kosaka Province may 

 be classified into mineral veins, black sulphide ores, and dis- 

 seminations. 



Mineral Veins: — These veins are of several kinds. They 

 always bear a greater or less quantity of sulphides, but some are 

 composed of auriferous quartz, some of quartzose copper ore, and 

 some rich in lead or zinc. Generally speaking, the deposits in 

 the province are the sulphide-rich, ''younger" veins of Vogt. 



As a type of the auriferous quartz veins, let me describe the 

 Hasami Gold Mine, for I know it better than any other of these 

 veins. It is situated about five miles to the south of the Arita 

 Station on the Nagasaki line of the Kyushu Railway. The mine 

 was discovered only fifteen years ago, but at present it is one of 

 the most important and hopeful gold mines in Japan. The 

 deposit is of the true fissure-vein type traversing the Tertiary 



