Copper-Tin Veins of the Akénobé District. 27 



(E) Faults. 



It is not surprising that numerous faults have been encountered 

 in underground workings in tliis highly disturbed district. In the 

 fitld, many faults are disclosed by the topography as weU as the 

 shifting of the outcrops of rocks and veins. In this district, almost 

 aU valleys are fault- valleys. That numerous faults with no surface 

 expression are also present is indicated by the fact that the veins 

 of this district are often exposed in the form of short fragments 

 cut sharply at both ends. The veins themselves commonly re- 

 present fissures formed by dislocation, accompanied with slickensides 

 and brecciation, although the}^ are naturally older tlian the faults 

 cutting them. Some conspicuous faults are shown on tlie annexed 

 geological map (PL I.). Two of the most remarkable, namely, 

 faults the Akénobé fault and the great cross fault of the Daisen 

 vein, are specially considered here. 



The Akénobé Fault. This is a X.-S. fault, passing through the 

 village of Akénobé. On the north of the village, it runs along the 

 Akénobé Elver, while on the south it runs along the flank of the 

 ridge to the w^est of the Daidô mine (PI. I.). It seems to dip 

 steeply toward the west. This fault is very significant in this 

 district, because' it sharply separates the Paleozoic terrane from 

 the Mesozoic. The foot- wall side of the fault consists of the green 

 slate complex of the Paleozoic age, and the hanging-wall side of 

 the Mosozoic black slate complex. To the north of the village of 

 Akénobé, on the opposite side of Higashiyama, this fault is welt 

 disclosed by topographic features. There it is expressed by a valley 

 between the high x^recipitous ridge consisting of the black slates 

 on the west side and the low isolated mountain consisting of the 

 green slates on the east. This fault is traceable further north- 

 wards. 



