Metallogeny uf the Jai>ancse Islands. 19 



southern extremity of the Satsuma Peninsula in Kyushu, where 

 there is an extensive lava plain of loose andésite, through 

 which nine independent rocky hills project, rising from 500 

 to 900 feet above the sea level. They are composed of a hard 

 compact rock of a whitish colour, the petrographical properties 

 of which are not definitely known. One geologist says it is a 

 quartz-trachyte, but others treat it as an andésite silicified. Although 

 all of the rocks are not quartz-trachyte, at least a part of the hills 

 belongs toit; besides, the properties of the ore-deposits are like 

 those of the Washinosu Mine. Nearly all the silicified rock 

 masses of the hills contain a trace of gold. In the Kasuga Gold 

 Mine, which has one of these deposits, the whole rock mass con- 

 tains 0.0002% gold, but in the cla^^ey veins running through it 

 the gold content is richest going up to 0.02% and even more. In 

 this ore-deposit, I recently discovered barite, which is always 

 present in black sulphide ores, but as yet has not been found in 

 other gold mines in the Satsuma Province. 



9. The Satsuma Province. 



The ore-deposits belonging to this province are associated 

 with andésite as their ore-bringer. In contrast to the Kosaka 

 Province, they are characterized by a scantiness of sulphides. The 

 ores are chiefly composed of auriferous quartz and calcite, both 

 belonging to the loivesf^ order of petrification and are generally 

 worked for gold. Transition is seen, however, between the 

 Satsuma and the Kosaka Province. For example, in the Sado 

 Gold Mine, which is supposed to belong to the Satsuma Province, 

 quartzose gold ores are associated with some sulphides, and in the 

 Kinkwaseki Gold Mine in Taiwan (Formosa), auriferous enargite 

 masses occur in the form of chimneys, while the Tasei Lode in the 

 Ikuno Mine, which is supposed to belong to the Kosaka Province, 

 is a true quartz vein. Generally speaking, the deposits in the 

 Satsuma Province are true veins, with banded, ring or brecciated 

 ores. The ring ores are most beautifully developed in the 



1) Perhaps gold and quartz are of colloidal origin. 



