IN KINGS COUNTY, N. S. HAYCOCK. 291 



recent times now extend for several miles up the drowned 

 valleys. That this topography is ptobably Pre-glacial is indi- 

 cated by the occurence of a layer of Boulder clay of variable 

 thickness mantling both hill and valley. The changes in topo- 

 graphy since the disappearance of the ice of the Glacial period are 

 exceedingly slight in this region and are confined almost wholly 

 to the deposition, during a subsequent slight submergence, of 

 some banks of stratified sand and gravel, some wearing away 

 and retreat of the coast cliffs, and the tilling-in of the river 

 basins mentioned. 



The North Mountain has the prevailing trend of the other 

 ridges, and would appear to owe its present elevation above the 

 valley to the harder and more resistant character of the sheet of 

 volcanic rock, which protects the underlying soft sandstone from 

 the action of the eroding agents that have worked with such 

 effect upon the unprotected sandstone to the south-east. The 

 junction of the sandstone and trap is some two hundred feet or 

 more above the floor of tne valley, and the conviction is forced 

 upon the observer, when looking south-eastward from this point- 

 that not only the smaller valleys mentioned but also the whole 

 broad depression he has crossed has been worn out of the soft 

 red sandstone, and that excepting minor inequalities of surface 

 the present relief of this part of the Province is wholly due to 

 differential resistance of the underlying rocks. 



The trap sheet retreats more rapidly along its edges than 

 the sandstone owing to frostwork and its vertical jointing, and 

 when they both appear in the face of the escarpment the over- 

 lying trap is never overhanging but always well behind the 

 sandstone which generally forms a steep slope upon which the 

 fragments of the trap are precipitated, forming broken masses 

 which conceal the contact of the two formations. Because of 

 the soft nature of the sandstone and its calcareous cement it 

 weathers much more rapidly than the trap wherever exposed to 

 the action of rain and wind, but since the jointing is not well 

 developed it is not affected to a very great extent by the action 

 of the frost. 



