G8 THE PENOKEE IRON BEARING SERIES. 



occurriug on the contact line between the grauitc and (juartzito formation in the 

 north part of T. tt7, R. Ii5, whicli I then isupposed to be quartzite altered by its con- 

 tact with the granite into a grauitelike rocik. Now I am more inclined to consider 

 the rock as a recemented mixture of granite fragments mingled with the arenaceous 

 material which formed the overlying ({uartzite beds. Still it is very singular that 

 the orthoclase crystals copiously imbedded iu the mass have all sharij outlines and 

 look as fresh, as if they had been formed where they are and were not debris of a dis- 

 integrated granite. 



At the above mentioned locality, iu the NW. i of NE. ^ of Sec. 24, T. 47, R. 43, 

 this singular rock in contact with the granite contains locally an abundance of brown 

 spar, which on exposed faces of the rock weathers out, leaving behind ochraceous 

 matter, which tills the spaces formerly occupied by the spar. . . . 



Only a short distance from the above described locality, in the adjoining Section 

 23, the granite is seen in contiguity with dioritic schists of a brecciated character, 

 which inclose large angular blocks of massive diorite of various qualities. The 

 granite comes there also in contact v/iih massive diorite belts and intersects them in 

 dike form. 



... In Sec. 13, T. 47, R. 40, the granite is found in close proximity to cherty 

 banded ferruginous beds, inclosing seams of good iron ore. Below these iron-bearing 

 beds are light colored kaolinitic strata, which arc in direct contact with the granite. 



Farther west, in Section 15 of the same town, the granite comes very close to 

 the ore-bearing quartzite formation, in which extensive exploring pits are opened, 

 but I had no opportunity to observe in this place which sort of rock came in con- 

 tiguity with the granite. The explorers informed me that diorite formed the foot- 

 wall of the (juartzites in which the ore deposits are found, and that the diorite joined 

 the granite on the south side. Onward to the west the explorers made to me the 

 same statements, always speaking of dioritic rocks intervening between the granite 

 outcrops and their exploring pits. 



Near the Montreal river, in the NW. ^ of Sec. 27, T. 47, R. 47, I found granite 

 in immediate contiguity with the ore-bearing quartzite and banded jaspery beds. 



In Wisconsin, above the island in the Gogogashugun river, a belt of schistose 

 dioritic rocks intervene between the granite and the large succession of light colored 

 slaty rocks which form the island. Above these slaty rocks are (juartzite strata- 

 partly brecciated and interwoven with seams of limonitic iron ore. From here to 

 Penokee gap I did not make any observations regarding the contact line of the 

 granite with other rocks, but at the Gap, in the bed of the river under a railroad 

 bridge, the dire«t superposition of crystalline limestone inclosing tremolite fibers on 

 the granite could be seen. Above the Innestone succeeded some beds of quartzite, 

 and then a large series of light colored silicio-argillaceous schists, which most likely 

 are identical with those composing the island in the Gogogashugun river. . . . 



