SABLE ISLAND—-MACDONALD. yay 
flood took piace, which swept away the finer portion of the 
material and sand to a lower level or seaward, leaving those 
perched rocks so frequently met with on hillsides and in valleys. 
Everywhere beneath our feet on this peninsula of Halifax 
where the bed rock is exposed are the deep groovings which 
attest to the powerful pressure it has been subjected to. 
From the labors of Dr. Honeyman, to whom this Institute is 
so much indebted for the geological problems wrought out by 
him in illustrating from time to time this drift period, tracing its 
boulders to their parent source, and by a train of evidence so 
strongly marked as to leave no doubt as to the distance and 
direction of their transportation, we learn something of the 
erosion our province has undergone while participating in this 
great ice period. 
The retreat or melting of the glacier was followed by a re- 
elevation of the land en masse, bringing above the surface an 
immense deposit of material known as the Champlain sands. 
As far as ascertained in the geology of our province the 
Champlain sands are wanting. Where shall we seek for the 
immense amount of finer material which must have been pro- 
duced in this erosion? The conclusion is obvious. The stria- 
tion on our rock surfaces all point to those off shore banks lying 
at right angles to the glacier. 
Is this deposit too great? Listen to the evidence of Sir Roger 
Murchieson, one of England’s greatest geologists, who, in speaking 
of the abrading effects of the ice period in which the British 
islands also participated, says : 
“Tn the silurian formation of those islands alone there is a 
mass of rock worn from the Jand which would form a mountain 
chain of 1800 miles in length, with a breadth of 33 miles, and an 
average height of 16,006 feet.” 
This implies a vast amount of finer deposit, and also gives us 
an idea of the changes that must have occurred in the topo- 
graphy of our province. 
In this Dominion, according to Sir Wm. Logan, there is in the 
triangle formed by Montreal, Champlain and Quebec, an area of 
9,000 square miles of the Champlain sands and clays, containing 
few boulders, and carrying grains of magnetic iron and garnets. 
