DESCRIPTION OF THE AREAS 273 



Upper Missi of quartzite pelables similar to the quartzite of the Lower 

 Missi is considered evidence of an unconformity. One boulder of con- 

 glomerate was also found in the Upper Missi conglomerate. Along the 

 northern border of the Upper Missi conglomerate-arkose area are bands 

 of hornblende-bearing schistose rocks that apparently belong to the sedi- 

 mentary series. 



The rocks of the Upper Missi group are poorly sorted. They consist 

 principally of a fairly feldspathic arkose now considerably recrystallized. 

 Much of it is conglomeratic, and neither the finer grained arkosic bands 

 nor the coarser conglomeratic bands have great linear extent. In many 

 places conglomerate bands a foot in thickness have a length of only a few 

 feet. A great variety of pebbles are found in these beds. Granite-gneiss, 

 quartzite, and vein quartz with considerable jasper are the most abun- 

 dant, but fragments of greenstone also occur. Some of the greenstone 

 fragments were apparently schistose before being included in the sedi- 

 ments, showing that a period of folding intervened between the extrusion 

 of the lavas and the formation of the Upper Missi conglomerate. No 

 well sorted rocks nor limestones occur and all the characteristics of the 

 whole Upper Missi group are those of terrestrial sediments laid down by 

 torrential streams under climatic conditions suitable for the maximum 

 of mechanical disintegration. 



Granite and granite-gneiss are intrusive into rocks of the Upper Missi 

 series and all the older formations. They are the youngest pre-Cambrian 

 rocks of the region. 



REED-WEKU8K0 AREA^ 



The Eeed-Wekusko area adjoins the Athapapuskow map sheet on the 

 east. The two form a continuous belt extending in an east and west 

 direction for a distance of 130 miles, but the former presents some fea- 

 tures distinct from the latter. The pre-Cambrian succession of the Eeed- 

 Wekusko area may be tabulated as follows : 



Batholithic intrusives Granite-gneiss and its differentiates. 



(Igneous contact.) 

 Wekusko group. 



Mica schist Garnet-staurolite and cyanite-bearing 



varieties. 



Garnet-gneiss. 



Graywaclte, arkose, quartzite, conglomerate. 



Slate and phyllite. 



Kiski volcanics. 



Autoclastics and pyroclastics. 



5 F. .7. Alcock : The Reed- Wekusko map area, northern Manitoba. Geol. Surv. Can., 

 Memoir 119. 



