HARviEj PAL^OZOICBRECCIAOFTHE VICINITY OF MONTREAL 273 



of calcite, quartz^, pyrite and carbonaceous matter. The sandstone is 

 usually largely composed of quartz, with a small amount of felspar. The 

 granite is a medium grained rock consisting wholly of quartz and felspar, 

 the felspar being principally orthoclase, with subordinate amounts of pla- 

 gioelase and microline. The grains of quartz and felspar are very numer- 

 ous in rounded, subangular and idiomorphic forms. The weight of evi- 

 dence presented by the slides goes to show that the quartz, felspar, zircon 

 and some of the apatite individuals, are fragments, very probably derived 

 from the granite. The apatite occurs both as large phenocrysts and in 

 needles, the phenocrysts being probably fragments. The needles are 

 well formed and very abundant throughout the groundmass. Perovskite 

 is very plentiful in some sections, usually as octahedra, but in some cases 

 granular. Some grains of highly refractive matter, having a dark border 

 of yellowish dust are very like leucoxene. Pyrite is present in small 

 amount. One section shows hydronephelite, occurring in aggregates 

 suggesting either residues of a groundmass or of amygdules, — most 

 likely of a groundmass. Some of it is quite coarse grained so that there 





Fig. 19. 



is little doubt as to the identity of the mineral. Other slides show an 

 unidentified mineral in the paste, having low refraction, dull polarisa- 

 tion, with extinction in some cases wavy, in others not. It is very similar 

 to hydronephelite. In some sections epidote is present in considerable 

 amount in thickset crystals. Carbonates form the bulk of the slides. In 

 some portions there are shadowy arrangements of the calcite very sug- 

 gestive of melilite; considering the presence of its usual associate, — 

 perovskite, this is not at all improbable. 



St. Paul Street, Montreal. 



A large mass of breccia was exposed when excavating a drain at 

 Lovell's bindery on St. Paul Street, one of the waterfront streets of 

 Montreal and directly opposite Ste. Helen's Island. It was not ascer- 

 tained whether this w^as in place or not; since however blocks of breccia 

 are frequently dredged from the bottom of the river it is not improbable 

 that this is an extension of the Ste. Helen's Island and He Eonde occur- 

 rence. It is exactly similar to the material from these places and has 



