\ 



278 THE PENOKEE IRON-BE AEING SERIES. 



future supplies of ore. From the shafts whicli stop at underlying dikes it is 

 possible to take out all the ore to the west and the ore to the east which lies 

 upon a higher level. That at lower levels to the east can be gotten out by 

 carrying the shaft to a greater depth, and drifting east until the deposit is 

 again found, or by putting in other shafts farther eastward. If the eastern 

 pitch of the dike (and therefore of "the deposit) is high enough, the first 

 method is the more economical for a certain distance; but with the low 

 eastern pitch whicli generally prevails, the second one has in practice usu- 

 all}' been followed. Each successive shaft to the east must pass to a greater 

 depth through barren rock before it strikes the ore body ; and if the devel- 

 opments of the future show that these ore bodies are of great depth, a 

 deposit will often l)e found to extend upon the land of an adjoining mining 

 company, as has been shown to be the case with some deposits* at the pres- 

 ent time. From the shafts thus resting upon the foot wall, drifts are ordi- 

 narily run along it east and west at each of the levels, and from these main 

 drifts crosscuts are run north. The drifts running west are continued .until 

 the underlying dike is penetrated. Upon passing through this dike, if it is 

 a basal one, the mixed ore or ferruginous chert is found. The drifts running 

 east continue in ore, alternating often with the lean phases and horses of 

 rock, until, on account of the eastern pitch of the ore deposits following the 

 dikes, it reaches-the top of them, when it runs gradually into poor ore, mixed 

 ore, and finally ferruginous chert. In general, the horizontal crosscuts to the 

 north are continued until the dikes are reached. Beyond the dikes is found 

 ferruginous v]un't or the regularly banded red ferruginous slates. Clean 

 ore is not usually continuous in all these directions in any one mine for 

 the distance abo\e indicated, nor are the rocks found at these outer extrem- 

 ities always such as are named above, but the boundaries of the ore 

 deposits are thus defined, at least in a general way. 



It is a question whether the present developments have not gone far 

 enouofh to warrant a radical clianoe in the manner of mining- iron ore 

 deposits in the I'enokee district. All over the lake Superior country such 

 bodies are well known to be extremely irregular. The deposits of the 

 Penokee range give promise, liowever, of greater regularity than has been 

 found in other districts. If they could be depended on to continue down- 



