SOME LOCAL DETAILS. 179 



St. Lawrence, though whether this was wholly a glacier 

 or in part a fiord leading from one, like many of those in 

 Greenland, does not certainly appear. Possibly, with 

 different levels of the land, these conditions may have 

 alternated. I cannot imagine anything more like what 

 the Saguenay may have been, than the Franz Joseph fiord 

 in east Greenland.* 



The strikes of the gneiss on the opposite sides of the 

 Saguenay indicate that it occupies a line of transverse 

 fracture, constituting a weak portion of the Laurentian 

 ridges, and this has evidently been smoothed and deepened 

 by water and ice under conditions different from the 

 present, in which it is probable that the channel is being 

 gradually filled with mud. Its excavation must have 

 taken place during a period of continental elevation in or 

 after the Pliocene period, and previous to the deposition 

 of the thick beds of marine clay (Leda clay) which appear 

 near its mouth and in its tributaries, sometimes passing 

 into boulder-clay below, and capped by sand and gravel. 

 It is indeed not improbable that in the later Pleistocene 

 it was in great part tilled up with such deposits, which 

 have been swept away in the course of the re-elevation of 

 the land. 



At Tadoussac, at the mouth of the Saguenay, where the 

 underlying formation is the Laurentian gneiss, the Pleis- 

 tocene beds attain to great tliickness, but are of simple 

 structure and only slightly fossiliferous. The principal 

 part is a stratified sandy clay with few boulders, except 

 in places near the ridges of Laurentian rocks, when it 

 becomes filled with numerous rounded blocks and pebbles 

 of gneiss. This forms high banks eastward of Tadoussac. 



* Second German Expedition, 1870. See also a paper by Prof. 

 Laflamme, Trans. R.S.C. 



