746 EDWARD STEIDTMANN 



Tanton^ maps and describes an area northeast of Lake Abitibi. 

 His succession of pre-Cambrian rocks follows. 



Post batholithic intrusives 



Olivine diabase 

 Keweenawan 



Quartz diabase, minette 

 Batholithic intrusives 



Granite and granite gneiss 

 Laurentian 



Igneous contact 

 Harricanaw series 



Arkose, conglomerate, graywacke 



Unconformity 

 Abitibi group 



Ferruginous dolomites and iron formation rhyolites, basalt, other 



volcanics, etc. 



The Kewagama Lake area described by Morley E. Wilson^ 

 includes about eighty square miles bordering on the Province of 

 Ontario. Cobalt is about thirty miles south of the southwest cor- 

 ner of the area. 



The region is a peneplain whose elevation above sea-level 

 varies from 900 to 1,100 feet. The divide between the James 

 basin and the St. Lawrence system crosses it along a sinuous east 

 and west line. Many of the low hills and streams of the region are 

 parallel with the rock structure, most of which trends north of 

 east. Some of the streams and lakes, however, have a strikingly 

 linear north and south direction. Wilson believes that they 

 follow preglacial depressions. 



The bed rocks are all pre-Cambrian. In many places they are 

 covered by stratified and unstratified glacial deposits and by 

 postglacial, finely stratified lake clays and sands. Wilson classifies 

 the pre-Cambrian rocks into two main divisions, but refrains from 

 correlating them with any of the units recognized by the Inter- 

 national Committee. 



The oldest division consists of highly metamorphosed and 

 folded rocks intruded by batholiths of granite and granite gneiss. 



' T. L. Tanton, "The Harricanaw Turgeon Basin, Northern Quebec," Canada 

 Geol. Surv. Mem. No. log (1919), 84 pp., i map, 9 pis., 2 figs. 



2 Morley E. Wilson, "Kewagama Lake Map Area, Quebec," Canada Geol. Surv. 

 Mem. No. 39 (1913), pp. 39-122, 24 pis., 9 figs., map in pocket. 



