Copi)er-Tin Veins of the Akénobé Dis-trict. 33 



direction, which wore once worked or entirely worked out and 

 abandoned, the Otaké and Higashiyama veins being most prominent. 



The Ôtaké Vehi, which runs parahel to the Nihonmatsu vein 

 and about 200 meters distant from it to the northeast, was once 

 worked for copper and tin ores. It is similar to the Nihonmatsu 

 vein in character, and is traceable for about 400 meters along the 

 strike, with a width varying from a fraction of one meter to several 

 meters. In the course of driving the main level, a bedded deposit 

 of cupriferous pyrite, intoisected by the copper-tin vein in question, 

 was encountered. Tlio w^all- rocks are green slates in association 

 with phylhtes striking N. 50° E. and dipping 15°-25°,to N. W. 

 This bedded deposit is similar in character to that which is being 

 worked at the Minamidani mine (p. 29). It is lenticular in form, 

 2 meters or more thick, and is associated with magnetite, especially 

 along the hanging and foot-walls, which are often intensely silici- 

 fied and grade into massive quartz. The high-grade ore from this 

 deposit contains 7% or more copix)r. 



2Vie Higashiyama Vein, once worked prosperously but now 

 temporarily abandoned, lies in the northern vicinity of the Otake 

 vein. It is exposed for more than 300 meters along the strike» 

 attaining in places a thickness of several meters. It was worked 

 for copper and tin ores as in the Otaké vein. 



The Daidô Vein Group. 



The Daidô vein group lies on the western side of the Akénobé 

 River, just opposite to the Daisen mine. Two chief veins are found 

 there, namely, Uwaban-hi (roof-vein) and Shitaban-hi (floor-vein), 

 both varying in width from a fraction of one meter to 2 meters or 

 more. They generally strike N.-S. and dip eastward very steeply, 

 but they intersect as indicated in PI. I. They are in places re- 



