582 THE GEOLOGY OF MINNESOTA. 



fOhloritese ___ 



Amphiboly 



No. 869. CHLORITE SCHIST (with rutile). 



[Chlorite schist, ^rgillyte. Hematite. 



~T6. 



From the southeast side of the same ridge as No. 868; sec. 32, T. 62-15 W. ; Tower. 

 Ref. Annual Report, xv, pages 247, 248, 266-268, 387; Bulletin ii, pages 44, 45, 234, 421. 



Meg. A soft, fine-grained, green, fissile schist. 



Mic. The section shows a schistose rock, the minerals being elongated in a 

 common direction. The principal components are quartz, chlorite, Muscovite and 

 rutile. The quartz is in fine grains, more or less- elongated. The chlorite and 

 muscovite are in plates, the former being much more abundant than the latter. 

 The most noticeable feature of the section is the presence of large numbers of minute 

 rutile prisms. These are commonly arranged with their long axes parallel to the 

 elongation of the other minerals. A few heart-shaped twins of rutile occur. 



Two sections. 



Age. Keewatin. u. s. G. 



No. 870. AKGILLYTE. 



Same place as No. 869. 



Ref. Annual Report, xv, pages 266, 268, 387. 



Meg. A fine-grained, gray-black argillyte. 



Mic. The section is composed of minute grains of quartz, perhaps also grains 

 of feldspar and flakes of chlorite and muscovite. Scattered through the rock is consid- 

 erable black, dust-like material, and there are also some minute rutile prisms. 



Two sections. 



Age. Keewatin. u. s. G. 



No. 871. HEMATITE. 



Lee mine, Tower. 



Ref. Annual Report, xv, pages 249, 387. 



Meg. Black, specular hematite, the ore of the Lee mine. 

 No section. 



Age. Keewatin. u. s. G. 



No. 871A. HEMATITE. 



Lee mine, Tower. 



Ref. Annual Report, xv, pages 249, 387. 



Meg. Specular hematite, with cavities which are lined with small crystalline 

 plates of hematite. 

 No section. 



Age. Keewatin. u. s. G. 



No. 872. AMPHIBOLYTE. ( Camptonyte? ) 



From a dike running E. 10 S.; sec. 21, T. 62-15, Stuntz island. 



Ref. Annual Report, xv, pages 308, 310, 314, 387. Compare No. 1847. 



Meg. The rock is granular, but much altered. 



