Xo. 1.] 3IATTIIEW — GEOLOGY OF NEW BRUNSWICK. 97 



side, and by the sinuosities of its channel. The Alpine glaciers, 

 therefore, being supported by the shoulders of the rocky ridges 

 along their sides, may be said (if one may be allowed the expres- 

 sion) to hang down from the gorges through which they flow, into 

 the valleys beneath ; and as their weight is thus materially re- 

 duced, their erosive power is lessened ; and they do not afford a 

 fair criterion of the amount of pressure which a continental mass 

 of ice, thousands of feet in thickness, would exercise upon the 

 rocky ledges of the region over which it might pass. Prof. Tyn- 

 dall's estimate of the weight of column of ice, would make this 

 pressure more than 7000 lbs. to the square inch beneath a glacier 

 2000 feet thick. Nevertheless the glacier which may once have 

 covered Acadia, has accomplished little in moulding the general 

 features of the surface. At many points around the New Bruns- 

 wick coal-fields, in the valleys among the Southern hills and on 

 the coast, tongues and islands of Carboniferous sediment, yet re- 

 maining, shew that the more prominent ridges and depressions 

 ante-date the glacial epoch. Prof Bailey draws attention to an 

 instance of this in the walls of a rather narrow depress;ion through 

 which the river St. John flows near Indian village, a few milc^ 

 above Fredericton. Patches of Lower Carboniferous conglomerate 

 may there be seen, plastered against the walls of slate, out of 

 which the gorge was originally cut. Similar instances occur in the 

 southern counties. Nor can the fiord-like bays of the southern 

 coast of New Brunswick be adduced as instances of glacial erosion. 

 Both the St. Croix and Digdeguash estuaries are Pre-Carbonifer- 

 ous. That of the Magaguadavic is crossed by the drift striae at 

 a wide angle, and the same may be said of other indentations 

 along the coast as far east as Beaver harbour. Lepreau harbour 

 and Basin, and Dipper harbour, are all transverse to the glacial 

 furrows, and Musquash and St. John harbours are too wide and 

 open to be regarded as fiords. Glaciers of the drift period may 

 have enlarged, but they certainly did not excavate the rocky beds 

 of these iuden Nations to any appreciable extent. Their form 

 though partly due to faults and folds of the older (Pre-Carbonifer- 

 ous) formations, is chiefly the result of erosion accomplished in 

 early Palaeozoic times. Although these larger indentations of the 

 coast line cannot be attributed to glaciers, the Boulder-clay betrays 

 the action of ice on the softer rocks of the country, as will be 

 hereafter shown. It is probable that ice assisted in enlarging and 

 deepening the small lakes and ponds, so numerous in tracts where 

 Vol. VI. a No. 1. 



