500 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Vov. VIII. 
veinlike appearance of many examples and also to the similarity of the 
concurring minerals to the ordinary veinstones. Many of the deposits 
have very much the appearance of veins, but Shaler!® has pointed 
out, that ‘in such cases the veins are very sharply contrasted with the 
country rock and are not dependent upon it for their component minerals. 
From this he deduces the important rule that such veins have been de- 
posited in previously formed crevices. 
16. It does not necessarily follow, however, that the mineral was 
not originally a clastic deposit, even though examples of evident vein 
occurrence are to be found. As has already been mentioned, the rocks 
of the district show such evidence of metamorphosis that none of them 
are in their original condition. Again there are not lacking instances 
of more recent, and in consequence more evidently organic phosphates 
occurring in deposits closely resembling veins. 
17. However, as is very evident, there is no unanimity of opinion 
to be reached by an examination of the deposits. The various observers 
have had the same series of rocks under examination, but have reached 
conclusions absolutely different. Penrose’s deduction after an examina- 
tion of the whole region is that the deposits are ‘‘mostly in irregular 
masses.’”!® Sterry Hunt in ’84!7 described its occurrence as inter- 
bedded in veins. In the latter form the mineral is much more impure 
and mixed with foreign material. When in bedded form the deposits 
show many of the characteristics of true beds and in fact often present 
striking analogies in structure to the coal measures. 
18. A famous locality for apatite is the Smith and Lacy mine near 
Sydenham, Ont., now operated for phlogopite by the General Electric 
Company. This Was visited by the writer as a typical example of the so- 
called vein occurrence of apatite. This mineral, originally the most 
abundant in the vein, has almost disappeared. The deposit occurs in a 
rusty gneiss and runs in a north-east direction. ‘The vein itself which is 
about ten feet wide goes downward almost vertically. 
16 Intro. to Penrose “‘ Phosphates” p. 38. 
16 Penrose, p. 37. 
147 Trans. Am. Inst. C. E. ’84 
