limestODe. 



Illustration. 



18 C GEOLOGICAL SURVEY OF CANADA. 



Kusty At the end ol" the t\venty-five miles from tlie forks, a rather coarse 



greyish rusty sandstone, in liorizontal 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 syenitic gneiss which is here seen 



Cliff of earthy ^^^ ^^^^ bottom of the rivcr. 



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 n\iles 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 di-ift clay, 

 which is also heajDcd above the beds forming the cliff on the left side. 

 Tlie 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 

 marl}" strata. The only fossils observed were some fragments of 

 encrinal stems and casts of Leptcena. 



The termination of this lowermost cliff is al)Out seventy miles from 

 the mouth of the I'ivei*. Between it and the commencement of the last 



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



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

 the limestone ci-opj^ing 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 numei'ous 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. A long- 

 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 bouldery 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 chalky nodules, while others liave straggling dark-colored patches 

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

 or forty miles from the mouth of the I'iver, the rock becomes more 



