36-fc THE GEOLOGICAL HISTOR\' OF THE 



becomes less pronounced, drurnlin-like hills of boulder-clay 

 increasing in abundance encroach from both sides upon the 

 valley and veneer the eastward extension of the table-land 

 beyond. Westwardly this table-land curves gradually in around 

 the head of the valley which, within a few miles, becomes a deep 

 gorge within steep walls. of slate. 



These topographic features are in part dependant on the 

 characters of the underlying geological formations ; in part they 

 depend on structural features, subsequent to the deposition, and 

 independent of the characteristics, of the rocks. 



In the region under discussion these rocks present consider- 

 able variety in texture and composition. Passing over the newer 

 and unconsolidated sediments, that form the marine marshes, 

 the terrace gravels, and the hills and sheets of boulder-clay, to 

 the foundation rocks of the district, we find uppermost and 

 resting against the lower slopes of the ridge at Wolfville a dull 

 red sandstone composed of a variable mixture of grains of 

 different minerals. Rounded particles of white and colorless 

 quartz appear to predominate, and minute gleaming flakes of 

 both muscovite and biotite are scattered through the rock. 

 Bright red specks are numerous, and according to their relative 

 abundance the sandstone varies considerably in coloring between 

 red and grey. The cementing matter is calcite, which is present 

 in considerable quantity filling the interstices between the other 

 minerals and effervescing briskly when the rock is touched 

 with acid The size of the grains also varies considerably and 

 rounded pebbles of white vein quartz are not uncommon. The 

 stratification is uneven and the beds dip north at angles of from 

 10 to 12 degrees. 



This sandstone, possessing the same general characters, but 

 varying in texture and in the relative abundance o its constitu- 

 ents, underlies the whole Cornwallis Valley and extends 

 westwardly for upwards of 90 miles. Eastwardly it forms a 

 narrow interrupted band along the margin of the Basin of Minas, 

 which appears to lie in a slight depression of its surface. 



Near Wolfville this formation, which is regarded as of 



