24 C GEOLOGICAL SURVEY OF CANADA. 



Marsh (the extremity of Beacon Point), will serve to show the appear- 

 ance of the clay banks of the Nelson along its lower section. 



FiratLimeatone The First or Lowest Limestone Rapid proved to be about seventy- 

 seven miles in a straight line from Point of Marsh, or about ninety by 

 the river. The foot of the rapid is in latitude 56° 36' 6-1". Here, and 

 at twenty-two miles higher up the river, the variation of the compass 

 is 11° 30', while at the place where the above photograph was taken it 

 is 8° 45'. Two more strong rapids over limestone occur at nine and 



First gneiss. ten m ^ es respectively above the lowest one. The first gneiss is seen in 

 the bed of the river ten miles higher up, and the limestone in the 

 banks disappears at two or three miles further on. The high clay 

 escarpments of the lower part of the river continue to the Limestone 

 Rapids, where they still have an elevation of about 100 feet, but they 

 have diminished somewhat where the limestone disappears ; and the 



b er ecia ati b anks " 3are banks skirting the river terminate near the foot of a chute with a 



ch ^ welvefeot perpendicular pitch of twelve feet, sixteen miles above the Third Lime- 

 stone Rapid. Beyond this, an occasional bank of clay is seen as far as 

 Gull Lake, but around this body of water and up to Split Lake the 

 country appears to be generally pretty level. A few species of marine 



in clay. shells were observed in the upper parts of the clay banks all the way 



from the mouth of the river to the twelve-feet chute just mentioned. 

 The only species met with at this upper limit were Saxicava rugosa 

 and Tellina proximo.. The elevation, as indicated by barometer, was 

 upwards of 200 feet above the sea. 



Pre-giacial ^ n m y re P ort f° r 1878 it was stated that the lower part of the Nelson 



channel. River appears to flow in a pre-glacial channel. Evidences of the exist- 



ence of such a channel were found in various places along the river all 

 the way to Split Lake. It was also mentioned in the report referred 

 Hi er channel * ' ^ at ^* e straight portion of the river between this lake and Sipi-wesk 

 along a great lies in a channel scooped out during the glacial period along the course 

 of a great dyke and afterwards filled with pebbly clay. In the neigh- 

 Loose shingle, bourhood of the Limestone Rapids, and for some miles both above and 



•fee, in hollows * ' 



in boulder clay, below them, the hard boulder-clay has been excavated in many places 

 and the hollows filled with loose boulders, shingle, gravel, sand and 

 stratified clay. For a number of miles before coming to the First 

 Limestone Rapid the banks on both sides are about 120 feet high and 

 consist generally of unstratified pebbly clay, but at a point on the 

 north-west side, between two and three miles below the rapid, from 

 twenty-five to fifty feet of sand, gravel and cobble-stones rest upon 100 

 Composition offset of this clay. Close by, to the north-east of this, the river bank 

 river an s. cons j s t B f yellow-drab fine sandy clay, and a little further on in the 

 same direction it consists of thirty feet of boulders, cobble-stones and 



