206 Sir W, E, Logan on the Quebec Group, SfC, 



edges of the strata would abut against this slope, and ultimately 

 both they and the early shallow water deposits on the higher 

 terrace would be covered over by the Birdseye, Black River, 

 Trenton, Utica, and Hudson River formations, as represented in 

 the accompanying diagram, (fig. 3.) 



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Without enquiring into the origin of the forces which have 

 produced the corrugations of the earth's crust, we may suppose 

 that if a sufficient lateral pressure were applied to strata thus 

 accumulated and arranged, there would result a set of parallel folds 

 and overlaps, running in a direction at right angles to that of 

 the pressure, with prevailing overturn dips in the direction of 

 movement ; the greater strength, however, of the solid crystal- 

 line gneiss in this particular case, offering more resistance than 



