30 



Vol. XLIir., Art. 5.— T. Katô: 



and dip very steeply to N. E., and are enclosed in the green slate 

 complex. 



The Daisen Vein is exposed on tlie steep slope of Shiroiwa- 

 daké, on the eastern side of the Akénobé Eiver, and is continuous 

 for more than GOO meters along its strike. Its width varies from 

 a fraction of one meter to 5 meters or more. It is the champion 

 lode in this district and produces tin and copper ores. The structure 

 of the vein is very characteristic and affords instructive data as 

 to the liistory of the vein formation in this district. It will be 

 fully described and discussed in a subsequent chapter (p. 39). 



The Nihonmatsa Vein lies to the north of the Daisen vein. It 

 is a typical copper-tin vein resembling the Daisen vein in structure 

 as well as in many other points, and plays a very important part 

 as a tin ore producer in this district. It is developed for more than 

 400 meters along the strike, the thickness varying from a fraction 

 of one meter to 3 meters or more. Toward the southern end, 

 the vein ramifies into two branches and becomes poorer in ore- 

 content. 



Fig 6. View of Sbiroiwn, daké (S), a:j seen eastward from the Meisei mine. 

 N ^îvilionmatsa mine. 



