CANADIAN ARCTIC 



635 



Fig. 40.2. Structural stratigraphic 

 elements of Arctic Archipelago. Re- 

 produced from Thorsteinsson, 1959, 

 which is revised after Fortier, Mc- 

 Nair, and Thorsteinsson, 1954. 



^ 



LEGEND 



Mainly (') Mesozoic and 

 Cenozolc shell sediments 



Unfolded miogeosynclinal 

 sediments, Cambrian- 

 Devonian 



Cratonic basin sediments, 

 A Ordovician - Silurian 



Precambrian Shield 

 rocks 



INNUITIAN OROGENIC SYSTEM 



Unclassified geosyncline 

 fold belts 



Miogeosynclinal 

 fold belts 



Eugeosynclinal 

 fold belt 



Structural trend of . 



fold belts ,*=^cr> 



Piercement domes ••»*• 



Margin of Shield >— > 4«_V 



G. S. C. 



geology of this area, but it is apparently underlain mainly by Archean rocks 

 with Protozoic strata along and north of the strait. 



The Boothia Arch occupies most of Boothia Peninsula, the western part of 

 Somerset Island, and fringes the southern part of the western shores of Peel 

 [Sound. It appears to be mainly of granitic rocks and gneisses, much folded 

 along a northerly to northeasterly regional trend. In the northern part it is 

 flanked apparently by Proterozoic strata which appear to form the outer limbs 

 of a geanticline. This northerly structure may have been in part the effect of a 

 late Silurian orogeny which has affected lower Paleozoic strata adjacent to the 

 Precambrian formations. Basic dvkes similar to the so-called diabase dvkes so 



widespread on the mainland Canadian Shield occur throughout the Precambrian 

 of Baffin, Devon, southern Ellesmere, Somerset, and Prescott Islands, and of 

 Boothia Peninsula. They are the youngest Precambrian rocks and their pre- 

 dominant orientation is northwesterly. 



The Wellington Arch, in southern Victoria Island, is apparend) made ex- 

 clusively of Proterozoic rocks in obvious extension of the Proterozoic strata of 

 Kent Peninsula and of Bathurst Inlet on the mainland. It trends northerly 

 through Washburn Lake and possibly joins the Minto Arch. 



The Minto Arch is much more extensive. It stretches from southern Banks 

 Island across the northern part of Amundsen Gulf to the west coast oi Victoria 



