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XLIII. — NOTES ON THE APATITE OF BUCKINGHAM, 

 OTTAWA COUNTY. By G. H. KINAHAN, M.E.I.A. 



[Read, December 15, 1884.] 



The apatite appears to "be diffused very like galenite in limestone. 

 It occurs in regular lodes, that is, veins with both foot and hang- 

 ing walls; in irregular veins, that is, having only one wall; in 

 string veins running irregularly through the rocks ; as " lay in lay " 

 on in veins between the stratification ; in bunches ; and I suspect 

 in pipe veins : of the last, however, I am not quite certain. 



According to the miners, it is always associated with a meta- 

 morphosed basic igneous rock, that the Canadians call " Pyroxene 

 rock" [but that I would class among MaccuUoch's "Hornblende 

 rocks," having more amphibole in them than diallage], and 

 quartzites. The " Pyroxene rock " seems always to be present, 

 and in general the quartzite, but not always. 



What I saw of the apatite reminded me very much of the 

 limestones and dolomytes that occur in the Irish Cambro-Silurians 

 associated with igneous rocks [eurites (basic felstones) andgabbro], 

 as these Cambro-Silurian limestones and dolomytes, or their petro- 

 logical equivalents, ophytes, steatytes, and such like, occur tangled 

 up with these igneous rocks, usually being more or less in bunches 

 or lenticular masses, and sending string veins into the igneous 

 rocks, or occurring as detached pieces or concretions in them, 

 while nearly always there are also quartzites associated with them. 

 Where our rocks are greatly metamorphosed, as in West Galway 

 and other places, the eurites and gabbro have become rocks similar 

 to those in the Buckingham township. 



It has therefore occurred to me that it is possible, if not pro- 

 bable, that the apatite has replaced limestone or one of the allied 

 rocks by chemical change or methylosis, as called by Dr. W. King, 

 of Galway. 



In favour of such a supposition, we find in the large bunches 

 of apatite portions that merge into pure limestone, while in other 

 places the rock will be in part apatite and in part limestone ; also 

 the bunches and irregular string veins remind one very much of 



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