PETROGRAPHIC GEOLOGY AND DESCRIPTIONS. 755 



Sandstone. Quartzyte.] 

 Magnetite. Gneiss. 



Mic. This rock consists of grains of quartz, rounded, somewhat increased in 

 size by secondary growth, its margins interlocking in a fine groundmass of inter- 

 locking quartz. It is like one of the sections described of No. 1633. One section. 



Age. Auimikie (Pokegama). N. H. w. 



No. 1639. SANDSTONE. (Green.} 



Same locality as No. 1638. 



Ref. Annual Report, xxi, page 153. 



Mey. Green, with included sand grains. 



Mic. Angular and sub-rounded grains of quartz are thickly set in a matrix of 

 amorphous green debris similar to much of that already noted at Wicks', but which 

 in this section is chloritic, rarely revealing any hornblendic remnants. One section. 



Age. Animikie (Pokegama). N. H. w. 



No. 1640. QUARTZYTE. (Pinkish.) 



N. W. M N. E. M sec. 32, T. 60-13, near Wicks'. 

 Ref. Annual Report, xxi, pages 85, 153. 



M<-g. Similar in aspect to No. 1632. 



Mic. This rock is coarser than No. 1632. It appears like a fragmental quartzyte 

 with borders (narrow) of secondary growth. Cotemporary, probably, with the sec- 

 ondary quartz has been an occasional development of a small grain of triclinic feld- 

 spar, in all respects like that in the quartzyte of Pokegama falls (No. 1525A), and 

 of microcline. These feldspars, however, may have been original clastic grains in 

 the rock. One section. 



Age. Animikie (Pokegama). N. H. w. 



No. 1641. MAGNETITE. 



" Magnetite from N. W. )^ N. E. J^ sec. 32, T. 60-13 ; natural loadstone, only found in small quantity ; 

 blends off into the rock of the iron belt (No. 1631 of the drill record)." 

 Ref. Annual Report, xxi, page 153. 



Mey. Rather coarsely crystalline magnetite. No section. 

 Age. Animikie. u. s. G. 



No. 1642. GNEISS. (Very finegrained.) 



At the so-called " silver pit," opened by Chester (compare No. 442), sec. 11, T. 59-14. 

 Ref. Annual Report, xxi, page 153; Bulletin vi, page 203, and foot-note. 



Meg. Average character of the rock of the dump at the old " Silver pit." Finely 

 siliceous. 



Mic. The rock consists largely of quartz, but also contains some feldspar. These 

 are very fine grained and interlocking, and hence wholly of secondary origin, the 

 original rock having been a jaspilyte. There are also clusters of fine globular grains 

 of pyroxene, probably diopside, and some hornblende, muscovite, sphene, and apatite. 

 One section. 



