326 APPENDIX. 



of which stands on its edges, have opposed but a feeble barrier ; 

 but the trap species, resisting with the firmness, as it has the color 

 of cast-iron, stand in masses which threaten the life and safety of 

 everything which may be hurled against them. I found a loose 

 specimen of sulphuret of lead and some common quartz in place 

 in the slate rock, a vein of clorite slate, and a locality of coarse 

 graphite, to reward my search. 



The Portage aux Coteaux, which is over the basetting edges of 

 the argillite, will give a lively idea of the effects of this rock 

 upon the feet of the loaded voyageurs. 



The sandstone is last seen near the Galley on the Nine Mile 

 Portage. Above the Knife Portage, some eight miles higher, 

 vast black boulders of hornblendic and basaltic blocks, are more 

 frequent ; and these masses are observed to be more angular in 

 their shapes than the boulders and blocks of kindred character 

 encountered on the shores of Lakes Superior and Huron. There 

 is a vast sphagnous formation, which spreads westwardly from 

 the head of the Coteau Portage, and gives rise to the remote tri- 

 butaries of Milles lac and Eum River. Much of this consists of 

 what the Indians term muskeeg, or elastic bog. Hurricanes and 

 tempests have made fearful inroads upon areas of its timber, and 

 it is seldom crossed, even by the Indians. This tract lies east of 

 the summit of sandhills and drift, which environ Sandy Lake, the 

 Konntaguma of the Chippewas. The portage of the Savanna 

 River, a tributary of the St. Louis, is the route pursued by per- 

 sons with canoes ; there is no other species of water craft adapt- 

 ed to this navigation. But wherever crossed, this swamp-land 

 tract imposes labor and toil which are of no ordinary cast. It is 

 the equivalent of the argillite which has been broken down and 

 disintegrated, forming beds of clay soil which are impervious to 

 the water, and we niay regard this ancient slate formation of 

 the true source of the St. Lawrence tributaries, as the remote 

 origin of those extensive beds of an argillaceous kind, which 

 exist at many places in the lower lakes and plains. 



Immediately west of the Savanna Portage, the Komtagama 

 summit is reached. This summit consists wholly of arid pebble 

 and boulder drift of the elder period. It exhibits evidences of 

 broken-down amygdaloids, which not only furnish a part of its 

 pebbles, but also of the contents of this stratum, in numerous 



