4G 



TIIK K'K A(iK IN CANADA. 



to Iti' oldtT tliiiii the soiilli-wosl slriac!. Tii soiiio other 

 ])arts of Cimiidii the -o striae sccin to ])v newer tliaii the 

 otluirs, hut there would lie iiothiun' iiiiprohahle in their 

 oc't'urriii_t;" hoth at the hegiiuiiuy' and end of tlie houhlor- 

 elav })erio(l. 



In sunnnin!,' up this suhjeet, I think it may he atlirnied 

 that when the striation and transfer of materials have 

 oliviously heen from X.E. to S.W., in the direetion of the 

 aretie eurrent, and more especially when marine remahis 

 occur in the drift, we may infer tliat floating" ice and 

 marine currents have heen the ellicient a<;ent8. Where 

 the striation has a local character, dependinti; u])ou exist- 

 in<;' mountains and valleys, we may on the other hand 

 infer the action of land ice. For many minor ett'ects of 

 striation, and of heaping' \\\) of moraine-like ridges, we 

 may refer to the jtresence of lake or coast ice as the land 

 was rising or suhsiding. This we now see ])roducing such 

 elt'eets, and I think it has not lieen sulticiently taken into 

 the account. 



As to the St. Lawrence valley, it is evident that its 

 condition (hiring the deposit of the houhler-clay must 

 have heen that of a part of a wide sound or inland sea 

 extending across the continent, and that local glaciers 

 may have descended into it from the high lands on the 

 north, and on the south wdiich may have heen relatively 

 higher than at present. During this state of the valley 



Fig. 1.— Travelled lioiilder on Glaciated Rock. (After Dr. G. M. Dawson.) 



