934 THE GEOLOGY OP MINNESOTA. 



[Mica schist. 



Mic. In this schist with much hornblende are zoisites which are small and 

 usually permeated by inclusions, among which is a vermicular form of quartz( ?) in 

 the fashion of a micropegmatyte. Epidote, Muscovite, sphene are accessory, the last 

 surrounding small grains of ilmenite* One section. 



Age. Keewatin, metamorphosed. N. H. w. 



No. 228S. MICA SCHIST. 



N. W. % N. W. y sec. 35, T. 58-21. 

 Bef. Annual Report, xxii, page 133. 



Meg. Muscovite schist. 



Mic. Quartz is abundant; muscovite and biotite with a little chlorite give the 

 rock a schistosity, and epidote lies nearly parallel with the structure, elongated 

 sometimes positive and sometimes negative (as cut) and showing conspicuous cross 

 fractures. One section. 



Age. Keewatin, metamorphosed. N. H. w. 



SPECIMENS COLLECTED BY A. D. MEEDS. 



No. 8M. MICA SCHIST. (Siliceous.) 



S. E. % S. E. J sec. 35, T. 60-13, two miles south of Iron lake. 

 Ref. Annual Report, xxii, page 88. 



Meg. Dark, granular, hardly schistose. 



Mic. In an interlocking, rather coarse mosaic of quartz, oligoclase and perhaps 

 other feldspars, are enclosed many biotites, which cut the quartzes independently, 

 and occasional Muscovites, the latter being apt to be clustered in or about certain 

 feldspar grains. The quartz varies greatly in granular dimension. Some of the 

 larger grains often involve many small ones which are globular, and so small some- 

 times or so nearly amorphous that in convergent light they transmit little or no 

 light between crossed nicols. One section. 



Age. Animikie. 



Remark. The structure is granular and much like that of muscovadyte. 



N. H. w. 



" Gneiss <J Pyroxine. Lacroix, p. 57, fig. 22. 



