398 E. M. BURWASH 



2. Lying above this is a predominantly sedimentary series whose 

 most important rock is an extensive and thick conglomerate com- 

 posed of the materials of the lower series with the exception of 

 two constituents, a granite which does not appear within the area 

 examined by Moore, and cherty fragments from iron-formations 

 which were also not found in the lower series, although similar rocks 

 are found in the upper series itself. These cherty fragments may 

 have come from portions of the lower (Rice Lake) series since 

 removed by erosion, or from parts farther east where they are 

 known to occur in the lower series. There is a possibility that a 

 gray gneissoid granite which may be seen on the Winnipeg River 

 intruding the Rice Lake series may account for the granitic pebbles 

 in the conglomerate. This gneissoid granite was not found in intru- 

 sive contact with the upper (Wanipigow) series and is older than the 

 red and grayish-yellow or white binary pegmatitic granites which 

 occupy most of the region, since these granites and the pegmatites 

 derived from them intrude the older gray granite, and the red 

 granite contains inclusions of it which, in many observed cases, 

 have themselves included xenoliths of the Rice Lake (Keewatin) 

 series. But while this is conclusive as to the relative ages of the 

 various granites and the volcanic series, it is not conclusive as to 

 the relative ages of the gray granite and the upper or Wanipigow 

 series. The Wanipigow may then be older than any of the local 

 granites and the pebbles found in its conglomerates may have been 

 transported from a distance. 



Comparing the Wanipigow conglomerate with that found in 

 the upper or Birch Lake series of the Lac Seul region, it is true of 

 both that they consist largely of pebbles derived from the volcanic 

 rocks which immediately underlie them. Both also contain frag- 

 ments of chert and jasper, which can be accounted for by the 

 presence of iron-formation in the lower series of the eastern field, but 

 are absent in that of the western area. In both, too, are pebbles of 

 quartz. In the Lac Seul area these are hard to account for. They 

 are well rounded and consist of a "sugary" white quartzite, partly 

 stained to a yellowish color by iron oxide, which shows under the 

 microscope "a granular texture of somewhat interlocking grains, 

 no secondary enlargement of grains, slight amounts of bleached 



