SOUTH WESTERN NOVA SCOTIA. — ^POWERS. 291 



prevent the growth of mature forests and leave in their wake 

 a scene of desolation — burned villages and square miles of 

 charred tree trunks laying bare the boulder-strewn ground 

 moraine. 



The present topography of the region is due to the dissec- 

 tion and drowning of the Cretaceous peneplain and to glac- 

 iation. The peneplain was uplifted probably toward the mid- 

 dle of the Tertiary and suffered erosion throughout the re- 

 mainder of the Tertiary. The land during this period ap- 

 pears to have stood higher than at present, long valleys being 

 formed which are now drowned. These valleys were formed 

 without respect to geological structure because the rocks have 

 about a uniform hardness and have been sufficiently metamor- 

 phosed to obliterate the primary structure and yet not to 

 produce pronounced cleavage. The submergence of the land 

 to its present level took place at about the time when the 

 Pleistocene ice sheet advanced over Nova Scotia. The sub- 

 mergence did not go below present sea level because there are no 

 marine beaches or wave-cut terraces above those being formed 

 at present. In the Bay of Fundy region there is evidence 

 of a recent uplift as is shown by the presence of marine fossils 

 in beaches 200 feet above water level. It is therefore evident 

 that there has been a differential uplift of the land in the 

 latter region. This tilting must have been at least as great 

 as two feet to the mile, as it is 108 miles from Shelburne to 

 St. John where the elevated beaches are found. 



The effect of glaciation has been to modify the topography. 

 Glacial erosion can be measured in at least tens of feet, for 

 everywhere the pre-Glacially weathered rock has been re- 

 moved, and the bed rock scoured and channeled. Roches 

 moutonnees are very frequent where wave action has re- 

 moved the glacial deposits. These rounded knobs are es- 

 peciall}^ noticeable at Port La Tour, forming islands at the 

 entrance to the harbour. 



Pnoc. & Tran'S. N. S. Inst. Sci., Vol. XIII. Trans. 20 



