On the Transition Rocks of the Cataraqiiu 95 



blende, anotlier strong evidence of the age of rocks, appears to have 

 asserted a complete mastery over the micaceous proportion of the more 

 ancient classes, and here may be studied, with considerable precision, 

 the singular struggle that takes place between felspar and amphib- 

 ole in the change of proportions in the elements of the crystalline 

 substances of transition greenstones and sienites. 



One of the greenstones of the Cataraqui, that hard and unman- 

 ageable rock in which the w^ells of Point Heiny have been, with in- 

 finite labor sunk, and which will be hereafter more particularly dcbcrib- 

 ed, is, in fact, a rock wherein hornblende, felspar and lime appear to 

 have had a chemical conflict, nor is it yet very clear which of these 

 compounds has at length obtained the victory, as notwithstanding the 

 dark color and amazing hardness of the mass, the slightest blow 

 leaves a very white surface and the whole effervesces almost as high- 

 ly as a compact limestone. 



The euphotide of Cedar Island, another evidence of the struggle 

 between amphlbole and felspar, also yields to the action of an acid.*^ 

 It yields, however, only slightly, as do all the odier varieties of grani- 

 tic a.2;2:re£:ates on the same Island, 



Ob'^t) 



A writer of the EncyclopoediaMetropolitana asserts that tlie Swed- 

 ish traveller Kal:^, found a granite on die banks of the St. Lawrence 

 in which lime occupied a most conspicuous position. Could he 

 have seen the rock of Point Henry, he would indeed have thought 

 so, but it w^as not then uncovered. 



The vast deposit of regularly stratified calcareous matter which 

 wo have called the limestone of the Cataraqui in connection with 

 granitic aggregates, into which that substance has intruded itself, will 

 offer a field of speculation that may tend to throw new lights on the 

 geological sciences, and when we find that animal remains exist in 

 very close connecdon with the felspathose portions we have again 

 still further cause to say, that tlie reladve ages of rocks are very far 

 from being yet well understood. 



It may be necessary in order to satisfy doubts, before we proceed 

 farther in this interesting subject, which we most sincerely wish may 

 soon b^ treated by some abler hand, to afford positive data, for the 

 assertion we have made, " that the limestone of the Cataraqui is de- 



* This serpentinite does not appear to affect the character of serpeiifme, by ihe 



presence of calcareous vein^ or threails pcrvailing it, no such signs Laving yet been 

 <liscovcrc<l. 



