PETROGRAPHIC GEOLOGY AND DESCRIPTIONS. 693 



Quartzy te. Granite. ] 



or zirkelyte. The most of the magnetite is found in borders along the belts of the 

 coarser crystalliths above. One section. 



Age. Animikie. 



Remark. The slide does not fairly represent the rock having this number, but 

 is evidently made from one of the thin, flinty lenticular parts embraced in No. 1324. 

 The rock itself is coarser. N. H. w. 



No. 1327. QUARTZYTE. (Actinotttic?) 



Northwest corner of sec. 23, T. 65-4, west from Gunflint lake. (Compare No. 1324.) 

 Ref. Annual Report, xvi, pages 80, 121 ; Annual Report, xix, pages 194, 201. 



Meg. Gray, quartzose, underlying a cherty magnetite. 



l//r. The quartz is wholly secondary, so far as seen in the slide, with inter- 

 locking borders, the grains being sub-rounded. If ever this quartz was of clastic 

 structure, it has lost it now, not even the boundaries of any original grains (except 

 rarely and doubtfully) being preserved. It is permeated in a loose manner by 

 conspicuous radiating rosettes of actinolite(1} fibres, each of the rosettes having 

 about the size of the individual quartz grains, making a handsome and unusual 

 appearance between the nicols. These fibres pierce the surrounding quartz in all 

 directions. The rosettes are not promiscuously placed in the quartz, but are at the 

 boundaries of the quartz. They have the appearance, as mentioned below, of having 

 grown up from some other original substance which was a constituent of the rock 

 before the metamorphism to which it has been subjected had acted upon it. The 

 rock, indeed, was probably a taconyte. The quartz, as well as the original glauconite, 

 if such were ever present, have been recrystallized simultaneously. 



Mingled with the "quartz, which shows no trace of rounded clastic boundaries, 

 is a liberal ingredient of volcanic glass, largely devitrified. In this substance the 

 actinolitic(?) rosettes take their source, radiating not only through the glass, but 

 also into the quartz adjacent. Some portions of this volcanic glass do not contain 

 these rosettes, but are charged with indefinite ultra-microscopic forms, which cannot 

 be determined. This rock is a phase of the taconyte of the Animikie. It is illus- 

 trated by figure 10, plate II. One section. 



Age. Animikie (iron-bearing member). 



Remark. The appearance of this rock in thin section is similar to that of 

 uxulianyte, which has tourmaline arranged in a stellate grouping, in quartz, but the 

 fibres in this are finer. N. H. w. 



No. 1328. GRANITE. 



Bottom of the test pit in N. W. % sec. 23, T. 65-4 W. 

 Ref. Annual Report, xvi, pages 80, 121. 



Meg. There are three specimens of this rock. One is a pinkish granite with 

 little hornblende (and biotite), and the others are much darker colored and much 



