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XLIV.— CANADIAN AECH^AN, OE PEE-CAMBKIAN EOCKS ; 

 WITH A COMPAEISON WITH SOME OF THE lEISH 

 METAMOEPHIC EOCKS. By G. HENEY KINAHAN, 

 M.E.I.A., &c. 



[Eead, December 15, 1884.] 



This Paper can only give a more or less general sketch of the 

 subject in hand, as the time I had to spend in Canada was very 

 limited ; but at the same time the opportunities for examining the 

 rocks were considerable. I would specially mention that the ob- 

 servations made, and the conclusions come to, were all personal ; 

 as, prior to visiting the different places and drawing my own 

 conclusions, I was unacquainted with the opinions of the various 

 writers on the subject, having read none of the literature connected 

 therewith, except Logan's Report many years ago. I must, how- 

 ever, allow that, as the readers of my Papers in connexion with 

 the supposed Archaean rocks in Ireland are aware, I have no faith 

 in merely lithological characters, or in the boundaries and divisions 

 founded solely on them : this circumstance may be supposed in 

 part to have more or less prejudiced my judgment. But as my 

 matured conclusions agree, as I find, in a great measure with 

 those of Logan and Selwyn, they may perhaps be worthy of 

 record. The title of this Paper is, perhaps, too presumptuous, as 

 more properly it is a review of the Irish highly metamorphic rocks, 

 and a comparison between them and some of the Canadian 

 Archsean or Pre-Oambrian rooks. As introductory to the subject 

 of the Paper, I beg to submit some observations on foliation, or 

 the structure induced by metamorphism ; and some other pheno- 

 mena connected therewith, the examples being nearly entirely 

 confined to Ireland, where this action has been more minutely 

 studied. 



Students of petrology and lithology seem now in general to 

 believe in three classes of metamorphism, namely. Regional and 



