454 



Macfarlane on the Acton Copper Mine. 



pit, was worked in September, 1861, and 161^ cubic fathoms of 

 rock excavated. These yielded : 



16^i|^ tons, first quality ore of 24.0 per cent. 

 21111 " crush " 4.5 " 



which, after deducting loss in dressing, correspond to 85 tons of 

 12 per cent ore. The eastern stope, consequently, contained 0.52 

 tons of 12 per cent ore per cubic fathom. The total expense of 

 excavation was $1292.00; or $8 per cubic fathom, and $15.1'7 

 per ton of 12 per cent. 



The distance from the underlying to the hanging wall, on the east 

 slope of Williams's pit, is 135 feet ; which extraordinary width is 

 wholly filled up by limestone of slightly different varieties. Next 

 to the foot wall may be observed a fine grained, light grey 

 limestone, with which thin leaves of slate are intercalated, the 

 slate being the more cupriferous. Further to the north-west, 

 there follows a limestone of a coarser grain and slightly darker 

 color, in which the richest copper deposits seem to occur. Por- 

 tions of this are also slaty, but less regularly so than the variety 

 just mentioned! Still further to the northwest, the first mentioned 



Section from g to h on the general plan, 



N. W. S. E. 



A, hill limestone ; B, underlying shale ; C, cupriferous limestone ; 

 D, hanging shale ; E, greenstone. 



slaty limestone again appears ; after which succeeds a cupriferous 

 limestone, characterised by being impregnated with copper pyrites, 

 and by containing here and there patches, consisting of silicious 

 matter and copper pyrites, which project from the surface of the 

 limestone, wherever it has been exposed to the influence of the at- 

 mosphere, in the form of moss-like efflorescenses. The extraor- 

 dinary thickness which the limestone attains in Williams's pit, 

 seems to be attributable to foldings in its strata. The stratification 

 of the limestone is very obscure, and is rendered more so by innum- 



