94 THE PENOKEE IRON BEARING SERIES. 



Concerning the iron-ore deposits fif the Gogebic range, Mr. Richard A. 

 Parker, M. E., indorses the oiiinion that there are not two \eins. He says of the ore- 

 bearing strata confined by the red slates and Jasper hanging wall that "there are not 

 in any sense two veins; in twenty or more miles of development there are but three 

 well established lenses of ore lying to the north of the strong foot- wall deposits, which 

 have been called north veins, and their interrupted occurrence is so rare, compared to 

 the continuity of more southerly deposits on the Laurentian schists, as to be scarcely 

 sufficient to warrant the use of the significant term 'vein,' which was adopted and 

 widely advertised by those interested in stock operations. As for manganese being 

 made the basis of distinction between two veins, there may be instanced the continued 

 occurrence of quite a^ regnlar percentage of it in the Kakagon and Bessemer mines, 

 while the develo|)(Ml proi)erties upon either side upon the same strike (Nimikon and 

 Superior mines) are entirely free from it." . . . 



Mr. Parker notes another point of intei'est in the frequency with which sheets of 

 talcose matter, locally known as "soap rock," penetrate the ore bodies. At some 

 period of develoi)ment of all the large mines these sheets have been found, varying 

 from 1 to -•■) feet in thickness. One of the cleanest and most easily observed sheets is 

 seen as the Hour of the open pit ;it the Aurora mine. It has a pitch about the same 

 as that of the ore lenses, l)ut cuts across the deposit at right angles to the dip, ending 

 when it reaches the tbot-w:ill (luart/.ite. It is soft, of smooth, even grain, and com- 

 paratively free from iron or iron stain. Where the ore came in contact with it the 

 former was decomposed for a foot or so, and the analysis showed that it contaiaed a 

 higher percentage ofphosphorns than usual (pj). ;{.")-.'5,S). 



Mr. Birkinliine by tliis time clearly sees that there is not in any sense 

 two continuous veins of ore in the region, as is shown by his quotation 

 from Mr. Richard A. Parker. In this the southerly dejiosits are explained 

 as occurring i>n the Laurentian schists. This is in no case coiTect, the most 

 southerly ore de])osits always being found upon a I'ragmental quartzite 

 which belongs to a group of rocks of which the iron-bearing member is one 

 formation What Mr. Parker says sbout the soapstone in the Aurora mine 

 terminating whi'U it I'eaches the foot-wall quartzite seems tome improbable. 

 He does not give any evidence that it does not cut the foot-wall quartzite, 

 and, considering that it is now known that these soapstones are dike-rocks 

 and in manv cases do not cut the foot-wall quartzite, it seems probable that 

 the same thing occurs here. 



BiRKiNBiNE (John). The Resources of the Lake Superior Region. Transac- 

 tions AnitM'ican Institute of Mining Engineers, vol, xvi, 18SS, pp. l((8-;i03. 



