PKE-CAMBRIAN LITERATURE OF NORTH AMERICA 749 



Wright^ says that the pre-Carboniferous rocks of the Clybum 

 Valley, Cape Breton, consist of a bedded series of volcanics invaded 

 by quartz diorite and granite batholiths and by sills and dikes of 

 basic materials. 



IV. MANITOBA, SASKATCHEWAN, AND NORTHWEST TERRITORIES 



Alcock^ has made a reconnaissance of the Lower Churchill 



River region of Manitoba and reports that the pre-Cambrian 



rocks of the area include the following: 



Pre-Cambrian 



Granite and gneiss Biotite granite gneiss, hornblende 

 granite gneiss, amphibolite, grano- 

 diorite, porphyritic granite 



Churchill quartzite Dominantly a dark gray, fine-grained 

 quartzite 



Keewatin Local areas of chloritic and sericitic 



schists 



Bruce^ has mapped and described the Amisk-Athapapuskow 



Lake area on the western border of the Canadian Shield on the 



boundary line between Saskatchewan and Manitoba. His 



succession follows: 



Kaminis granite 

 Granite gneiss 

 Hybrid granitic rocks 

 Intrusive contact 

 Upper Missi series Arkose 



Conglomerate 

 Unconformity 

 Lower Missi series Slate 



Graywacke 

 Quartzite 

 Conglomerate 

 Unconformity 



Cliff Lake granite porphyry 

 Intrusive contact 

 Kisseynew gneisses 



Amisk series Sedimentary and igneous gneisses and schists, lavas, 



tuffs, agglomerates, and derived schists 



' W. J. Wright, " Geology of Clyburn Valley, Cape Breton Island (Nova Scotia), " 

 Canada Geol. Stirv. Summ. Kept. 1913 (1914), PP- 270-83, map, diagram. 



' F. J. Alcock, "Lower Churchill River Region, Manitoba," Canada Geol. Surv. 

 Summ. Kept. 1915 (1916), pp. 133-36. 



3 E. S. Bruce, "Amisk-Athapapuskow Lake District," Canada Geol. Stirv. Mem. 

 No. 105 (1918), 91 pp., map, 7 pis., 4 figs. 



