64 



THE POST-PLIOCENE PERIOD. 



ology. In reasoning, however, on this subject as regards Nova Scotia, 

 I have the advantage of appealing to causes now in operation within 

 the country, and which are at present admitted by the greater number 

 of modern geological authorities to afford the best explanation of the 

 phenomena. In the first place, it may at once be admitted that no 

 such operations as those which formed the drift are now in progress on 

 the surface of the land, so that the drift is a relic of a past state of 

 things, in so far at least as regards the localities in which it now rests. 

 In the next place, we find ; on examining the drift, that it strongly re- 

 sembles, though on a greater scale, the effects now produced by frost 

 and floating ice. Frost breaks up the surface Of the most solid rocks, 

 and throws down cliffs and precipices. Floating ice annually takes 

 up and removes immense quantities of loose stones from the shores, 

 and deposits them in the bottom of the sea or on distant parts of the 

 coasts. Very heavy masses are removed in this way. I have seen in 

 the Strait of Canseau large stones, ten feet in diameter, that had been 

 taken from below low- water mark and pushed up upon the beach. 

 Stones so large that they had to be removed by blasting, have been 

 taken from the base of the cliffs at the Joggins and deposited off the 

 coal-loading pier, and I have seen resting on the mud-flats at the 

 mouth of the Petitcodiac River a boulder at least eight feet in length, 

 that had been floated by the ice down the river (Fig. 11). Another 



Fig. 11.— Travelled Stone, Petitcodiac River. 



testimony to the same fact is furnished by the rapidity with which 

 huge piles of fallen rock are removed by the floating ice from the base 

 of the trap cliffs of the Bay of Fundy. Let us suppose, then, the 

 surface of the land, while its projecting rocks were still uncovered by 

 surface deposits, exposed for many successive centuries to the action 

 of alternate frosts and thaws, the whole of the untravelled drift might 

 have been accumulated on its surface. Let it then be submerged 

 until its hill-tops should become islands or reefs of rocks in a sea loaded 

 in winter and spring with drift ice, floated along by currents, which, 

 like the present Arctic current, would set from N.E. to S.W. with 

 various modifications produced by local causes. We have in these 



