194 THE VERMILION IRON-BEARING DISTRICT. 



In the cases mentioned the iron-bearing formation was found in imme- 

 diate contact with the greenstone at a great number of places. In all cases 

 the contact is sharp. There is no gradation from the greenstone through a 

 distinctly clastic transitional rock into the iron-bearing formation. The 

 field relations described are evidently such as could be produced only by 

 the closest infolding of a superimposed rock in the rock below it. This 

 intricate infolding is furthermore shown by the contorted character of the 

 banded iron formation. 



The iron formation is not confined to the normal relatively uumetamor- 

 phosed greenstones, but is also found in those which have been inetamor- 

 phosed by contact with the granite into the amphibole- and mica-gneisses, 

 as in the occurrence in the SE. \ of sec. 32, T. 62 N., R. 13 W., south of 

 Burntside Lake. In passing, it may be mentioned that the presence 

 of the iron formation in these amphibole-schists and gneisses is further 

 proof of the correctness of the statement already made that these are but 

 much metamorphosed greenstones, and essentially the same, at least so 

 far as their original condition is concei'ned, as the greenstones which are 

 not very far distant. 



Reference has been made to the fact that the jasper at the contact 

 with the greenstone is sometimes brecciated. One especially clear case of 

 this is the occurrence on the south side of the North Lee pit. Here the 

 jasper fragments derived from the iron-bearing formation are, especially 

 near the greenstone, more or less completely surrounded by a matrix 

 of the adjacent greenstone, which evidently, under the pressure exerted 

 upon it, became more readil}^ plastic than did the more brittle jasper. Com- 

 monly brecciation does not occur at the contact. The greenstone is usually 

 schistose along- such contacts. This is illustrated 220 paces north of the 

 southeast corner of sec. 15, T. 62 N., R. 13 W. Here there is a bare roche 

 moutonnee, which consists for the most part of the very dense massive 

 greenstone. At one place there was found a belt of schistose greenstone 

 about 3 feet wide lying immediately next to the massive form above 

 mentioned. In this schistose greenstone there are two narrow bands of 

 east-west striking jasper, each about 4 inches in width. These were 

 separated from each other and from the massive greenstone by the schistose 

 form of the greenstone, wliich to the south as well as to the north grades 

 into the massive variety. It is hardly possible to interpret this occurrence as 



