260 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Along the line on which our observations were made, there has been 
unequal positive uplift of the earth’s crust. The force responsible for 
this great piece of work has been applied locally and in varying degree. 
The result is that to-day the actual distance from the centre of the earth 
of every point on that line is greater than it was at the close of the 
glacial period. 
The coastal belt shows a degree of elevation considerably less than 
that demonstrated for the region east and southeast of James Bay. Snp- 
plementing the data of Low’s and De Geer’s maps with the writer’s 
observations on the northeastern coast, one is led to the conclusion that 
the uplift of the glaciated tract of this part of America has been greatest 
near the region of the central névé.' The result is to strengthen De 
Geer’s parallel between the postglacial behavior of the earth’s crust in 
northeastern North America and in northwestern Europe. The bearing 
of this conclusion on the theory of isostasy is obvious. Perhaps the re- 
latively great uplift of Newfoundland is connected with the local charac- 
ter of its glaciation, which, according to Chamberlain, was not due to an 
extension of the ice-fields of the mainland.? 
BouxLpER BarricapEs. — There is not wanting an indication that on 
the Labrador coast, at least, the land is higher to-day than in any other 
part of postglacial time. Wherever the shore slopes are not too steep, the 
coast is belted with lines of innumerable large boulders visible between 
low and half tides. These accumulations may be called “ barricades.” 
The name is recognized as appropriate by any one who attempts to land at 
low water by forcing a small boat through a gap in the nearly submerged 
wall of boulders. The barricade is situated twenty to one hundred or 
more feet from the shore according to the slope of the foreshore; the 
distance is greater as the slope is the more gentle. Plate 9 gives a 
typical view of one seen at Ford Harbor. Lyell long since figured an 
example in the “ Principles of Geology (ed. 11, 1892, Vol. I. p. 381). 
Of particular significance is the fact that, in practically every case 
where one of these accumulations was examined, it proved to be com- 
posed essentially of large glacial erratics. These are believed, in most 
cases, to have been derived from the wave-swept zone immediately above. 
As the land emerged, the boulders were dragged down in the undertow 
and lodged just below the level where the surf could move them. The 
relative absence of boulders between the shore and the barricade is also 
explained in part by the action of coast-ice, which floats off such boul- 
ders when the ice-foot breaks up. If the boulders happened to be 
1 Proc. Bost. Soc. Nat. Hist., 1892, vol. 25, p. 464. 
2 Bull. Geol. Soc. Amer., 1894, vol. 6, p. 467. 
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