75° 



EDWARD STEIDTMANN 



CamselP reports on the results of a reconnaissance of a portion 

 of the northwest territories between longitudes io8°3o' to ii4°3o' 

 and latitudes 58°3o' to 6i°3o'. His classification of the pre- 

 Cambrian rocks of the area follows. 



Athabaska sandstone (sandstone and conglomerate) 



Unconformity 

 Granite and gneiss 



Intrusive contact 

 Tazin series (mica, chlorite, and quartz schists, slates and limestone) 



Camsell and Malcolm^ present a reconnaissance map and 

 report of the Mackensie River basin between longitude ioo° to 

 135° and latitudes 55° to 68°. Pre- Cambrian rocks occur along 

 the eastern border . of the basin. Their classification of the 

 succession follows. 

 Late pre-Cambrian Sandstone, limestone, and basic flows and intrusives 



Unconformity 

 Granite and gneisses 



Intrusive contact 

 Early pre-Cambrian Schists, slates, limestones, and quartzites 



Mclnnes^ reports on a reconnaissance of 220,000 square miles 

 lying between 91° to 106° longitude and 53° to 59° latitude. The 

 area extends from Lake Winnipeg to Fort Churchill on Hudson 

 Bay eastward to Prince Albert. The area is underlain chiefly 

 by pre-Cambrian rocks excepting on the southwest corner, which 

 is underlain by Cretaceous. Most of the pre-Cambrian rocks 

 resemble the Laurentian of the Lake Superior region. In the 

 eastern portion are found patches of the Keewatin and Grenville 

 type. Sandstones like the Keweenawan of Lake Superior are 

 abundant in the northwest part of the area. The classification 

 of the pre-Cambrian by Mclnnes follows. 

 Keweenawan ? Athabasca sandstone — ^White and dull red, coarsely granular, 



siliceous sandstone and conglomerate in thick, horizontal 



beds 



' Charles Camsell, "An Exploration of the Tazin and Taltson Rivers, Northwest 

 Territories," Canada Geol. Surv. Mem. No. 84 (1916), 124 pp., 18 pis., i map. 



^ Charles Camsell and Wyatt Malcolm, "The Mackensie River Basin," Canada 

 Geol. Surv. Mem. No. 108, 154 pp., i map, 14 pis. 



3 William Mclnnes, "The Basins of Nelson and Churchill Rivers," Canada Geol. 

 Surv. Mem. No. 30 (1913), 146 pp., 19 pis., i map. 



