40 'I'HK K'K ACK IN CAXADA. 



Tlioii^U'li the lioiildcr-clay often in'csciits a soincwliat 

 \vi(l('ly ('.\l('iiil('(l and uiiit'orni slu'tJl, yd il may lie slated 

 to till up all small \alleys and depressions, lo lie (M»nlined 

 eliieHv to the lower urounds, and to l)e thin or al)seiil on 

 ridges and risiuLi' urounds. The Koulders which itcontains 

 are also hy no means uiul'orndy dis])ei'sed. W'lieic it is 

 cut through liy ri\-ers, or denuded hy the action of the 

 sea, ridges of lioulders often appeal' to he included in il. 

 Those on llu' Ottawa referred to in the ''(leolouy of 

 Canada," ji. S'.l.'i, are \-ery Liood illustrations, and I luivo 

 oliserved tlu' same fact on the Lower St. Lawrence and on 

 the coast of Xo\a Scotia. It is also oliserxaMe that ihese 

 lines and ui.mps of liouldeis are often not of local 

 material, hut of rocks from distant localities, and that a 

 number of the same kind seem often to lane heon 

 deposited to,u"ether in one <j;roup. 



Loose boulders are oft-en found upon the sui'face, and 

 sometimes in ,u'real numln'i's. in some instances Ihest' 

 may rejtresent beds of boulder-(day i'emove(l by denuda- 

 lion. In otiier cases they may have been deri\ed from 

 the (jverlyin,!^ memliei's of tlu' formaliitn, or may have 

 been dejjosited on the surface in the later I'leistoeene 

 sul)sideiu'e, without any coNcriiiL;' of clay or gravel. In 

 "Acadian (leolony," p. 04, I have illustrated the manner 

 in which larue stones, sometimes ein'ht feet or more in 

 diameter, are moved by ilie coast ice and sometimes 

 deposited on the surface of soft mud, and I have had 

 occasion to \erify the (jbservalions of the same kind made 

 by Admiral JJaytield, and (pioted ])y Sir C. liyell in the 

 " Principles o( (Jeoloey." Lastly, tin certain hinh yrounds 

 there are large loose l)0ulders, which have probal)ly been 

 moved to their present positions by means of land ice or 

 glaciers. 



