71 



to such a depth ? This very question gives us a clue to one factor at 

 least in the estimate of the powerful ice-iuass which, coming from the 

 West or W. N. W. struck down upon the shales and limestones of the 

 formations here to be found. It also gives us data to estimate its 

 thickness. The occurrence of striated rocks at the top of old Barrack 

 Hill, where the Parliament Buildings now stand, shows that as that 

 clitF is one hundred and eighty-seven feet above the level of the river, 

 and over two hundred feet above the level oi the bed of the river, the 

 mass must have been much over two hundred feet. Further, in order 

 that a mass of ice or a glacier carrying boulders and detritus moraine- 

 profonde can groove and polish the rocks of a district to such an 

 extent as was the ca.se here, the superincumbent weight and attending 

 pressures must have been enormous, and from what is known of present 

 glaciers, whether in alpine or arctic regions, we know that its thickness 

 must have been very great. A fair estimate, we believe, of the thick- 

 ness of the glacier or mer-de-glace extending over our city and its 

 environs during the glacial epoch must have been vrry little short of one 

 'thousand feet, if indeed that number is not too small. The erosive or 

 denuding force of glaciers has as yet only casually been touched upon, 

 for when we take into consideration the millions of tons of 

 material which have been i-emoved from even the small area 

 about our city, it is marvellous to know where it all went. You can 

 hardly find a loose rock or boulder in the fields without seeing v/ritten 

 upon it indubitable marks of scratching and grooving, which, along with 

 millions of othei-s were held firm in a mixture of cementing clay and 

 sand (to a small extent) carried forward upon the floor of the glacier and 

 ground one against the other, at times, to such an e.xtent that all 

 angularities and rough points were removed and the boulders left smooth 

 and polished. The striations, grooves and polished surfaces of rocks 

 which up to this date attest clearly to the fact of the existence of those 

 glaciers, besides the boulders themselves, may be seen not only in the 

 places already mentioned, but at the corner of Sussex and Rideau streets, 

 where th-:?x-e is an interesting exposure. 



The eflFect of these glaciers upon the softer shaly strata of our 

 neighbourhood is clearly shown in such a de])Osit of the Utica shales as is 

 met with at Cumming's Bridge, on the Rideau River, or at the corner of 



