Copper-Tin Veius of the Akénobé District. 



3^ 



The vein is composite in structure. It represents a shattered 

 zone filled with ores, gangue minerals, and fragmc-nts of partially^ 

 or entirely altered country rock, and the filled fissures have been 

 repeatedly reopened and recemented by successive mineralizations 

 (Fig. 9). In some places, however, the structure of the vein is 

 very irregularly massive and brecciated. 



^-^^' 



Fig. 9. Diagrammatic sketch of a vein- piece from Daisen. About 1/5 natu midsize. 

 E, country rock; T, cassiterite ore of the first stage of mineralizafion, with specks 

 and streaks of chak^opyrite, etc.; w, quartzose wolframite-cassiterite ore of the second 

 stage of mineralization ; C, chalcopyrite veins and veinlets of the third stage of 

 mineralization ; Q, milky quartz with a little chalcopyrite (fifth stage of mineraliza- 

 tion). Zincblende veinlets of the fourth stage of mineralization are not represented 

 here. 



Fig. lO. Diagrammatic sketch of the exposure at a worldng place in the 

 northern part of the Daisen vein (Kominé). 

 ], country rock; 2, cojyper-tin ore; 3, wolframite-bearing tin ore; 

 4, copper ore ; 5, barren quartz. 



