42 j 



GEOLOGICAL SURVEY OF CANADA. 



Character of 

 country on 

 route. 



Timber. 



Rocks along 

 route. 



ridges, ending in a small lake fifty chains across, followed by another 

 portage of forty- three chains to a large irregular body of water called 

 A-pi-cho-ti-ne-chits Lake, which is drained by Bishop Roggan River. 



Between Big and Bishop Eoggan rivers the country is made up 

 of ridges of low rounded gneissic hills rising from fifty to two hundred 

 feet above the general elevation of the land, which is estimated from 

 an average of the barometer readings taken, to be six hundred and 

 seventy-five feet above sea level. These hills are partly covered with 

 boulder sands and clays, while the intervening valleys are filled with 

 deep mossy swamps and small lakes. 



The greater part of this region has been burnt over by frequent fires, 

 which have in many places left the higher parts totally devoid of 

 vegetation. The trees remaining arc second growth black spruce, 

 tamarae and banksian pine, never exceeding fifteen inches in diameter 

 three feet from the ground. On the lower swampy lands and around 

 the margins of the small lakes, where the fires have not destined the 

 older trees, a dense growth of small black spruce and tamarac prevails 

 with an occassional balsam spruce. On the portage leading from 

 Pi-a-go-chi Lake, a few balsam poplars, four inches in diameter, were 

 seen along with small red cherry trees, this being the northern limit of 

 the latter. 



Except in the immediate vicinity of Big River no stratified 

 superficial deposits occur on this portion of the route. The sands and 

 clays seen were unstratified and mixed with boulders. On the higher 

 ground sand predominates, owing probably to the greater part of the 

 clay being washed out of the thin deposits there overlying the rock, 

 and carried down into the lower vallej^s, where the clay is greatly in 

 excess. 



On the first portage from Big River are exposures of pink and 

 grey coarse-grained hornblende orthoclase gneiss. Strike S. 60° W. 

 Similar gneiss, highly contorted, is seen on the second portage. 

 Coarse pink hornblende orthoclase granitic gneiss, containing angular 

 fragments of dark, finegrained hornblende schist was seen on the third 

 portage. On the fifth portage similar gneiss occurs along with a pink- 

 micaceous variety. Strike E. and W. Highly contorted pink and grey 

 hornblende and mica gneiss, having a general strike of S. 20° W., is 

 exposed on the seventh portage. On the eighth and ninth portages 

 the rock is more micaceous, with great numbers of barren quartz veins. 

 On the latter portage, fifteen chains from the south end, is a dark 

 green diorite dyke, weathering deep brown, with a fine-grained com- 

 pact structure near its contact with the surrounding gneiss, but rather 

 coarsely crystalline in the mass. This dyke is two hundred and thirty 

 feet wide and runs N. 2T W. 



