THE LOWER HURONIAN. 303 



which make angles somewhat less than a right angle with each other. The 

 schistosity in the softer bands, prodnced as the result of shearing, is nicely 

 shown in places on these sediments. 



RELATIONS. 

 RELATIONS OF THE SEDIMENTARY MEMBERS OF THE SERIES TO ONE ANOTHER. 



The relations of the Ogishke conglomerate, the iron-bearing- Agawa 

 formation, and the Knife Lake slates to one another is that of three 

 conformable formations, with the Ogishke conglomerate at the base and 

 the Knife Lake slate at the top. They occur constantly in. this position, 

 the iron-bearing formation being wanting at some places, but present at 

 others. There are gradations between the formations. The lines which 

 have been drawn are based upon the petrographic character of the rocks 

 and the preponderance of the various kinds. 



RELATIONS OF ' THE LOWER HURONIAN SEDIMENTS TO THE ADJACENT FORMATIONS. 



RELATIONS TO THB AHCHBAN. 



Relations to JEli/ greenstone. — The relations of the Lower Huronian 

 sediments to the Archean greenstones are clearly shown at a number of 

 places where the Ogishke conglomerate has been found in association with 

 them. As a rule the conglomerate lies upon the flanks of the greenstone 

 anticlines and is made uj) chiefly or solely of pebbles and bowlders which 

 can be identified with the rocks constituting the Archean complex, so as to 

 show unmistakably their source. Thus, for example, at a great number of 

 places south of Moose Lake the conglomerate was observed in direct 

 contact with the greenstones, which occur in conspicuous ridges forming 

 the cores of the anticlines. Li some places the conglomerate lies immedi- 

 ately adjacent to the fine-grained ellipsoidal greenstone, and at other 

 places, where the ellipsoidal portions have been removed by erosion from 

 the greenstone mass, the conglomerate lies against the coarse-grained 

 greenstone which normally is at some distance from the border of the 

 greenstone areas. Moreover, wherever finer-grained forms of the elastics 

 showing bedding occur, it is usually found that this bedding is essentially 

 parallel with the contact of the sediments and the underlying greenstones. 



The contact of the Ogishke conglomerate with the greenstones was 

 also observed on the north side of Twin Peaks ridge and the occur- 



