282 



THE VERMILION IRON-BEARING DISTRICT. 



be shown on the map without great exaggeration. Sometimes the con- 

 glomerate is practically wanting, and then the slates abut against the 

 Archean, although, as a rule, actual contacts of the slates' and ndjaceut 



Fig. is.— Detail map of the ea.st end of El;.- Island, Vermilion Lake. Minne.sota, showing actual rock exposures, by J. Morgan 

 Clements and C. K. Leith, 1S99. 



f(.)rraations are wanting, erosion along the contact having removed the 

 slates, which are softer than the other rocks at these places. 



The I'elation of the sediments to the granites of Vermilion Lake is 

 exactly the same as their relation to the greenstone and the iron formation. 

 The basal conglomerate lies next to these eruptives normally and consists 

 chiefly of pebbles, which can be identified with the rocks immediately 



