Section IV, 1922 [i4l] Trans. R.S.C. 



Bottom Deposits of McKay Lake, Ottawa^ 

 By E. J. Whittaker, M.A. 

 Presented by E. M. Kindle, A.B., M.S., Ph.D., F.R.S.C. 

 (Read May Meeting, 1922) 



Introduction 



The writer was engaged during a part of the field seasons of 1916 

 and 1917 in a comparative study of the fossil fauna of the rnarl deposits 

 of McKay^ Lake, near Rockcliffe, Ottawa, and the present fauna of 

 the lake. The results of this investigation were published in the 

 Ottawa Naturalist? While dredging to 'ascertain the fauna in the 

 lake at the present time, a peculiar red ooze was discovered in the 

 deeper parts of the lake, which showed remarkable lamination and 

 was very unlike the more common freshwater«sediments. This was 

 of sufficient interest to warrant study into the bottom deposits of the 

 lake as a whole, and this paper is the result. 



McKay or Hemlock Lake in Rockcliffe, Ottawa (see Plate I, A), 

 is well known and readily accessible to all Ottawans, and during the 

 war became more familiar than usual to many as it lay on the route 

 to the soldiers' camp and rifle ranges. It is a small body of water 

 only about 500 yards long and having a greatest breadth of about 

 200 yards. One-eighth of the total water area is occupied by a bay, 

 the bay indenting the eastern shore to a depth of about 150 yards. 

 Its greatest depth is only about thirty feet, although it is difficult to 

 determine the exact point at which the sounding lead hits bottom, 

 owing to the oozy character of the latter in the deepest parts. The 

 history of this basin dates back to the end of the Pleistocene when the 

 land emerged from the Champlain Sea. Topographically the lake 

 has two distinct types of shoreline. On the west side where bed rock 

 of Chazy age is exposed, the shores are high, low ramparts of sand- 

 stone outcrop and peaty or mucky deposits are absent. Elsewhere 

 the lake is surrounded by beds of marine sands and clays, and here 

 the shores are low and owing to the considerable quantity of mucky 

 and peaty deposits can scarcely be approached on foot except at the 



^Published by permission of the Director, Geological Survey, Ottawa. 



"Whittaker, E. J. The Relationship of the Fossil Marl Fauna of McKay Lake, 

 Ottawa, to the Present MoUuscan Fauna of the Lake. Ottawa Naturalist, Vol. 

 XXXII, No. 1, pp. 14-19. 



