lOj^ TMK UK A(iK IN CANADA. 



TIk^ Montroiil luouiiliiiii, like oLluir isolated trnppeaii 

 hills ill the ureal plniii of the lower St. Lawrence!, ]»n'S(Mils 

 a steej), erjiLT^fy li'oiit to llic iioith-east, and a loiij,' slope or 

 tail to the soulh-wc^si : iind in front of its north-east side- 

 is a bale, r(«'ky plateau of yreat extt^nt, and at a height of 

 ahont L'OO feet above the river. This ])lateau must have 

 been ]»roduecd by marine denudation of tht! solid mass of 

 the moiuitain in tla; I'leistocene i)eiiod, and proves an 

 astonish injf amount of this kind of erosive action in hard 

 limestones interleaved with tiaj) dykes, and which have 

 been <j;round and polished with ice at the same time that 

 the plateau was cut into the hill. T>y ice, also, must the 

 tli'bi'ifi ])roduced by this enormeais erosion have been 

 removed, and ])iled alonj,' the more sheltered sides of the 

 hill in the l>oulder-elay. 



With rctiiard to the cra,t,'-and-tail attitude of Montreal 

 mountain, I have to observe that in lar^'e masse.s of this 

 kind reachiui^ to a considerable height, and risin*;' above 

 the I'leistocene sea, the north-east, or expf)sed, side has 

 been cut into steep clifl's, ])ut in smaller i)rojections (jf the 

 surface over which the ice could frrind, the ex])osed side is 

 smoothed, or " moutonnee," and the sludtered side is 

 angular. ^V little reflection nmst sh(»w that this nnist 

 be the necessary action of a sea burdened with heavy 

 floating ice. 



These facts have been well illustrated in the extensive 

 limestone ([uarries lying on the ])lateau already referred 

 to behind the city of jMontreal, and north-east of the 

 Montreal mountain. At this place the surface of the 

 limestone has been ])olished and striated, the direction of 

 the striae ranging from N. 50" E. to N. 70° E. Not only 

 has tlie surface been intensely glaciated, but ledges of 

 rock of great size have been lifted up and pushed to the S.W. 



