TWENTY-FOURTH ORDINARY MEETING. 297 



accompanied by a very crystalline and distinctly spotted or mottled 

 diorite in which the hornblende is dark green or black, and the 

 felspar white, grey or reddish. A dull red, rather fine-grained 

 gneiss, streaked and spotted with dark grey or black, is found in 

 proximity to the apatite deposits in some parts of Ottawa county. 

 Interstratifying the gneiss near a number of the apatite deposits in 

 the valley of the Li^vre, I have noticed thin seams and also beds, up 

 to several feet in thickness, of a quartz-rock which is white or light 

 bluish in color, semi-translucent, non-crystalline or compact, pitted 

 or honeycombed on weathered sui-faces, the cavities being apparently 

 due to the dissolving away of felspar. 



It is well known that some of the metals exhibit a preference, 

 locally at all events, for certain rocks which, as the miners say, are 

 " kindly " to them ; as for example (among the old crystalline rocks),, 

 oxides of ii-on with hornblende schists, galena with limestone, sul- 

 phides of copper with greenstone and talcoid schists, gold with 

 quartz, tin with granite, etc. There is thus nothing extraordinary 

 in the association of the apatite of the Laurentian system with 

 pyroxenite. 



We have seen that, in regard to the apatite of Ottawa county at 

 any rate, there are certain pretty well ascertained geological and 

 mineralogical associations, so that should we find these conditions 

 repeated in another region, among the widely-spread Laurentian 

 rocks of Canada, we may look with some confidence for apatite. 

 These conditions may be briefly recapitulated as follows : a somewhat 

 .regulai^ large-scale structural arrangement of the gneiss in bands, 

 having distinctive characters and accompanied by limestones, a con- 

 siderable number of "the Laurentian minerals," and the presence 

 of pyroxenite or of mottled diorite. For these reasons I have ven- 

 tured to predict the probable discovery of apatite in the Parry Sound 

 district ever since 1876, when I made a geological reconnoisance of 

 the district and found five distinct limestone bands, of which the 

 general positions and courses were indicated, and to which I gave 

 separate names —(See Geol. Survey, Report of Progress, 1876-77, 

 pages 202-208). The general structure and character of the Lauren- 

 tian rocks to the north-eastward of the Geoi'gian Bay would place 

 them among the higher divisions of the system. In this region I 

 also found the mottled diorites and the pyroxenites which, in the 

 county of Ottawa, indicate the proximity of apatite. A considerable 



