326 THE VERMILION IRON-BEARING DISTRICT. 



of this iron-bearing formation at a ninnber of places in the area, but in each 

 instance the occurrence is so small that no attempt has been made to show 

 them on the map. Mention of these localities is made under the heading 

 "Interesting localities," page 330. 



Exposures. — The exposures are not very numerous, but by means of 

 them the belts may be confidently traced out along the strike, and these are 

 shown on the accompanying map only as far as they have been followed. 



STRUCTURE. 



The iron formation occurs in narrow belts, having a very uniform 

 strike, but the beds of these belts show varying strike and dip throughout 

 their extent, indicating- that the formation has been folded to a greater or 

 less extent. The greatest amount of folding was noticed in that portion of 

 the iron-bearing formation that occurs on the portage between Wind and 

 Moose lakes. At this place the jasper is extremely crenulated and broken. 

 In some places this folding is so extreme that the bands have been fractured 

 and the fragments drawn out into pebble-like areas having no apparent 

 connection with the adjacent pieces; in others, however, the thin string-like 

 ends may be connected with other laminse of jasper which, when followed 

 out, thicken and grade into other pebble-like areas of jasper. 



On the divide on the Wind Lake-Moose Lake portage the iron 

 formation is exposed in three different belts, all three essentially parallel 

 in trend. These are exposed only for a short distance along their strike. 

 The belts have very much the same appearance. They are intensely 

 plicated, and it seems from close study that they all belong to the same 

 horizon; that we have here, in other words, a single iron formation which 

 was intricately folded into the subjacent conglomerates, and that the folds 

 were then ti'uncated, making the formation outcrop at three different places 

 in one horizontal section so as to look like three superimposed belts. It 

 is confidently believed that if the exposures were perfect they could be 

 followed along the strike and connected with one another. 



On That Mans, Agawa, This Mans, and The Other Mans lakes, in 

 Canada, the iron formation is closely folded into a syncline, the beds 

 standing practically on edge. Slates occupy the center of the syncline, 

 and in going away from this center in both directions, north and south 

 across the strike of the beds, one g^oes from lower to lower beds. More- 



