limestone. 



Illustration. 



18 C GEOLOGICAL SURVEY OP CANADA. 



Rusty At the end of the twent} T -five miles from the forks, a rather coarse 



greyish rusty sandstone, in horizontal beds, makes its appearance on 

 the right side of the river, and continues for three miles, or to the 

 Portage Chute above referred to. In one place it forms a cliff twenty 

 feet in height, and rests upon the red sycnitic gneiss which is here seen 

 Clift' of earthy m the bottom of the river. 



On the opposite, or left side of the river, a cliff of greyish-buff very 

 crumbling earthy limestone or calcareous marl begins at the Portage 

 Chute, and continues for eight miles downward with a height varying 

 from thirty to fifty feet. In this interval the same rock crops out in a 

 few places on the opposite side of the river from beneath the drift c\&y, 

 which is also heaped above the beds forming the cliff on the left side , 

 The accompanying view, looking down the river, is copied from a 

 photograph taken two miles and a half below the Portage Chute, and 

 Last gneiss. shows the appearance of the banks in this vicinity. The last of the 

 red syenitic gneiss is seen in a rapid at the termination of the long 

 A second limestone cliff above described. Here another escarpment of the marl}" 



limestone, like the one just passed on the left side, and of about the 

 same height, begins on the right side of the river and continues for 

 upwards of four miles, while the opposite bank consists of drift 

 clay with the limestone exposed in one place. Thin irregular and 

 interrupted beds of tolerably pure grey limestone occur among the 

 marly strata. The only fossils observed were some fragments of 

 encrinal stems and casts of Leptcena. 



The termination of this lowermost cliff is about seventy miles from 

 the mouth of the river. Between it and the commencement of the last- 

 Banks of stretch, a distance of upwards of thirty miles, the banks are from 

 drift ciay. seventy to one hundred and fifty feet high, and consist of drift clay with 

 the limestone cropping out here and there at the base on either side. 

 The latter is likewise exposed at a short distance back from the main 

 banks in the ravines cut by numerous tributary brooks. The limestone 

 also occasionally extends across the bed of the river. The channel of 

 the Churchill in this section is evidently of pre-glacial origin. Along 

 it a considerable thickness of drift rests upon the uneven surface of the 

 limestone, filling its inequalities with a mixture of boulders, gravel 

 and clay. The undisturbed pebbly and bouldeiy clay is also sometimes 

 observed to fill the angle between the ancient cliff and the river bed. 



Along this part of the stream the limestone becomes less earthy and 

 of a dolomitic character. Some of the stronger beds are mottled with 

 white chalk}* nodules, while others have straggling dark-colored patches 

 running over their surfaces. At the commencement of the last reach, 

 or forty miles from the mouth of the river, the rock becomes more 



