<) F T II 15 R O C K S O F L A K E S U P E R I U R. 



237 



with a tint of grayish green. In some places, contains flesh-coloured felspar. Wea- 

 thers with a slightly rough, iron-shot surface. 



279. Greenstone — colour, grayish black j the felspar honey-coloured, some of the 

 crystals large ; some large crystals of hornblende. 



280. Greenstone — very coarsely crystalline. 



281. Decomposing crystals of hornblende in a felspar paste. 



282. Siliceo-argillaceous shale — highly metamorphosed ; colour, dark purplish 

 gray; thinly laminated ; same as No. 100; rings like phonolite when struck. Is 

 associated with basaltic beds ; joints contain stilbite. 



283. Syenite (?) — colour, flesh-red; highly crystalline; the felspar predominates; 

 weathers slowly, and with a tolerably even surface. Differs little, if at all, from 

 the highly metamorphosed beds of No. 213. 



284. Greenstone — colour, very dark gray, almost black ; minutely crystalline ; 

 the hornblende predominates. 



285. Siliceo-argillaceous shale ; highly metamorphosed ; colour, brick-red ; very 

 compact; fine-grained; almost homogeneous; resembles jasper; contains a few 

 small lumps and scales of quartz ; fracture uneven ; weathers with a smooth sur- 

 face ; no incrustations ; very hard. Some of the beds are less compact, and inclined 

 to be shaly. 



286. Basaltic rock — colour, dark gray, almost black; is jointed, and shows a 

 laminar structure ; a thin crust of iron rust between the lamina?, and in the joints ; 

 is generally homogeneous, but exhibits, in some places, minute crystalline points. 

 Weathers with a smooth, black surface. This rock is separated from No. 287, by 

 beds of amygdaloid. 



287. Volcanic grit — colour, reddish gray, with a slightly greenish tint; fine- 

 grained ; tolerably compact ; many grains of thalite (?) disseminated through 

 it. This rock bears considerable resemblance to some of the altered sandstones. 

 Contains numerous grains of peroxide of iron. 



288. Metamorphosed siliceo-argillaceous shale — colour, brownish red; amygda- 

 loidal, the cells filled with zeolites ; has a very rough, hackly fracture ; shows 

 evidences of thin lamination, rendered indistinct by metamorphic action. 



289. Metamorphosed shaly sand-rock, or volcanic grit (?) — colour, brick-red ; 

 slightly amygdaloidal ; contains a few rounded siliceous pebbles. 



290. Metamorphosed sand-rock — colour, grayish red ; compact; contains many 

 minute crystals of yellow iron pyrites. Belongs to the finer grit beds. 



291. Basaltic rock — fine-grained ; colour, dark gray, with a slightly reddish tint. 



292. Argillaceous iron ore. 



293. Basaltic rock — fine-grained; colour, dark purplish red; fracture, smooth, 

 conchoidal ; nearly homogeneous ; has a few minute crystalline points. 



294. Metamorphosed siliceo-argillaceous shale; colour, red; fracture, sharp, 

 uneven ; very hard ; has a baked appearance ; contains occasional small crystals of 

 felspar. Resembles the " Great Palisade" rock. In contact with No. 293. 



295. Same as No. 294 — less compact ; shaly ; has a greater resemblance to the 

 quartzites. The less altered portions show a granular structure. 



