3 Iwasaki : 



blende are present. It is a question whether the gold was deposi- 

 ted with sulphide minerals as a primary product, or has been 

 accumulated around the sulphides by secondary enrichment in 

 process of time. 



Copper ores in this province are often found in contacts, as at 

 Kapsan in Korea, and Naganobori and other places in Japan proper, 

 where gold veins of the Korean type are very scanty. The author 

 studied contacts in the Naganobori Copper Mine in the prefecture 

 of Yamaguchi. This mine is thirteen miles distant from the 

 Ogori railway station, near the western extremities of Honshu. 

 There is an extensive 'karst\ called Akiyoshi-dai. Through the 

 limestone a small granite boss ^bOOO feet long and 1,700 feet wide, 

 is exposed forming a hillock named Hanano-yama. All around 

 the boss, contacts are found, Naganobori being one of them. 



The deposits of tlie Naganobori Mine are 30 feet tliick, the 

 hanging-wall l)oing limestone and the foot-wall granite. The 

 greater part of the ores consist of radially aggregated augite, which 

 is either mixed with garnet crystals, or planted upon garnet 

 nodules. The ground-mass of the ore is a mixture of quartz and 

 calcite, in which eol)altite crystals and chalcopyrite masses are 

 imbedded. The chalcopyrite is always amorphous, but the 

 cobaltite crystallizes in pentagonal dodecahedrons, showing 

 cubical cleavage. Throughout the ore body, mineral veins with 

 symmetrical structure are frequently met with. I'hese consist of 

 quartz in the salband, calcite in the middle, and tetrahedrite on 

 both sides. Branching out from the main body of the contact 

 deposit, veinlets of chalcopyrite traverse the limestone. In my 

 opinion, the ore of the deposit was petrified from the emanations 

 emitted fron^. the granite magma. First, ferromagnesian silicates 

 have crystallized out as garnet and augite, then cobaltite, 

 chalcopyrite, quartz, tetrahedrite and calcite were formed one 

 after the other. 



6. The Kitakami Province. 



This province gets its name from the fact that the metal mines 

 in it are most flourishing in the Kitakami Mountain-land, situated 



