142 A. p. COLEMAN — MARINE AND FRESHWATER BEACHES 



or a single large one can not be decided with the information now at 

 hand. It should be mentioned that a sand terrace on the shore of 

 Geneva lake, 45 miles south, has an elevation of about 1,400 feet, and 

 that gravel plains, with kettle hol^s, at a height of 1,335 feet occur 20 

 miles to the west, on the divide between the waters of Spanish river, 

 flowing into Georgian bay, and Matagami river. 



The extensive gravel and sand deposits just referred to as occupying 

 the watershed between Hudson bay and the Saint Lawrence system of 

 waters were evidently formed at the ice margin during a long halt of the 

 retreating glacier, and the low passes to the north and northeast were 

 no doubt filled by the ice, preventing any connection with Hudson bay, 

 whether the region stood at that time at sealevel or not. If they were 

 formed by salt water it must have been an extension of the gulf of Saint 

 Lawrence; but it is probable that the much lower ground eastward to- 

 ward lakes Temagami and Temiscaming, the latter only 581 feet above 

 the sea, was still covered with a great lobe of ice, since in the lower parts 

 the ice-mass must have been coi'respondinglv thick, and hence slower in 

 melting. This ice-lobe may even have extended down the lowlands near 

 the Ottawa to the Saint Lawrence, and so have ])rovided the sui)posed 

 ice-dam of lakes Algonquin and Iroquois, in which case the Algonquin 

 beach must be imagined as extended as far as Meteor lake, with a rather 

 rapid differential elevation of 200 feet between Cartier and Meteor lake, 

 40 miles to the north. 



The source of the immense beds of sand and gravel must have been 

 glacial, since the rocky hills rising throat;!! the plains could not have 

 afibrded any large part of the materials, being entirely Laurentian, while 

 much of the gravel is of Huronian rock. It appears as if the gravel must 

 have been transported largely against the slope of the country', which 

 falls away toward Hudson l)a3'' on the north and toward Temiscaming 

 on the east. The glacial strife seen in the region run from south to 25 

 degrees west of south. It is perhaps possible that subglacial streams may 

 transport materials,even coarse gravel, up grade by means of the hydraulic 

 ])re^sure of the column of water derived from the high level of the ice- 

 surface in the rear, much as hydraulic elevators lift gravel in the western 

 placer mines. 



Southeast'of Meteor lake a succession of similar sand and gravel plains 

 stretches, with a few interruptions, for 40 miles, following in a general 

 way the lake SN'stem of Vermilion river, though the headwaters of Mon- 

 treal and Wahnapitae rivers also start from the neighborhood of Meteor 

 lake. As one advances southeast the level gradually sinks by a series 

 of steps until near lake Wahnaj^itae similar plains with lake-filled ket- 



