448 THE GEOLOGY OF MINNESOTA. 



[Quartzyte. 



rock is of other material, viz.: feldspar, containing many inclusions, seldom showing 

 a polysynthetic striation, biotite, sometimes greenish, these two embracing the 

 quartzes as in a pervading matrix, and accommodating themselves to their forms. 

 The red color of the rock comes from the hematite which stains the feldspar. 



Age. Altered Animikie. N. H. w. 



No. 609. QUARTZYTE. ( Metamorphosed. J 



Pigeon point. Similar relation to the dike No. 605, but further from it than No. 608. 

 Ref. Annual Report, ix, pages 69, 70; Annual Report, x, pages 57, 58. 



Meg. The weathered surface is spotted irregularly with red and gray. The 

 interior is spotted in the same way, but in some places, on fresh fracture, appears 

 like a red granite. 



Mic. The elements of the clastic rock seem to have been wholly recrystallized, 

 in some parts of this rock. The quartz shows no remaining traces of evident clastic 

 origin, but is angular and fresh, its form being imprinted in the surrounding f.eld- 

 spathic portion. The feldspathic portion is red and was later to take position than 

 the quartz. It is so clouded with ferruginous matter that it can simply be said to 

 be crystalline, darkening regularly, but its cleavage and striation of twinning (if it 

 had it) are invisible. It is presumed to be orthoclastic. While these compose the 

 most of this rock, it also contains biotite and chlorite, while hematite serves as pig- 

 ment generally. One section. 



Age. Animikie. N. H. w. 



No. 610. QUARTZYTE. (Metamorphosed.) 



Pigeon point. Near the same place as the last, but further from No. 605. 

 Ref. Annual Report, ix, pages 69, 70; Annual Report, x, pages 57, 58. 



Meg. This rock is very similar to the last, but has more of the red element. 

 Mic. The microscopic characters are not observably different from those of 

 No. 609. One section. 



Age. Animikie. N. H. w. 



No. 611. QUARTZYTE. (Metamorphosed.; 



Pigeon point. Near the same place as the last, but further from the dike No. 605. 

 Ref. Annual Report, ix, pages 69, 70; Annual Report, x, pages 57, 58. 



Mi'!/. This is a more crystalline rock, appearing like an imperfect red syenyte. 



Mir. Along with the foregoing minerals mentioned in No. 609, can also be seen 

 here a striated feldspar, much stained with the same ferruginous substances, and a 

 single angular small grain that resembles sphene. One section. (See figure 30.) 



Age. Animikie. 



