328 The Drift or Boulder Formation. 



are almost all of primary origin, and the evidence tliey present is 

 in unison with that derived from the gravel and sand, to prove 

 that at some remote period the surface has been covered with, 

 water having a current from the north. 



" As bearing upon the probable direction of this current, it may 

 be mentioned that in several places between Niagara and Hamil- 

 ton, along the mountain or ridge which has been alluded to, 

 where the drift has been removed, the rock beneath has been 

 found to present a smooth and almost polished condition, with. 

 a gently undulating surface, marked by deep parallel grooves 

 and scratches, whose general direction is from north to south. 

 These grooves are well displayed in the quarry of Mr. Kifler, at 

 Thorold."* 



The smoothing, polishing and grooving of the rock surfaces 

 are phenomena intimately connected with the origin of the drift, 

 and present so many different features that it has been found 

 impossible to devise any one theory that would account for them 

 all. Where the drift is removed, and the surface of the solid rock 

 laid bare, it is found to have been almost everywhere subjected to 

 a grinding process, as if an immense sheet of sand paper had been 

 drawn over the country from the north towards the south. 

 Sometimes flat surfaces of limestone several acres in extent will 

 be found in part polished like a looking glass, but usually furrowed 

 by long parallel scratches, as fresh in appearance as if they had 

 been made but yesterday. In places where the strata are tilted 

 up, so that their edges project, these will often be found planed 

 down to an uniform level. Where mountains or low hummocks 

 of rock have been subjected to this process, the striae are often 

 seen to pass up the slope and over the summit. In such cases it 

 is always the north side of the mountain that has received the 

 polish, while the southern extremity remains untouched, thus 

 afl'ording another proof that the whatever it was that produced 

 the scratches or polish moved from the north towards the south. 

 In geology the abraded end of the mountain is called the strike 

 side, and the other the lee side. On any good recent exposure of 

 these glacial striae, the observer will be instantly struck, not only 

 with their freshness, but also with their exact parallelism. In 

 different parts of the country their direction is also different, but 

 in the same neighborhood they follow the same course, even over 



* Report on the Progress of the Geological Survey of Canada, ISilj by 

 Alexander Murray, Esq., Assistant Geologist. 



