MAGNETITE GARNET ROCKS CQUL80N. 305 



VII. DESCRIPTION OF PLATES. 



PLATE I. 



Fig. 1. No. 181, Porphyroblastic-Magnetite-Garnet-Gneiss. Photo, F. L. 

 Still well. Note that the scale photographed with the specimen in this plate is 

 graduated in inches. 



Fig. 2. No. 650, Porphyroblastic-Magnetite-Garnet-Schist, with a well-defined 

 " linear " structure. Photo, F. L. Stillwell. 



PLATE II. 



Fig. 1. No. 527A, Chlorite-Magnetite-Schist, showing the alteration of garnet 

 into a mass of quartz, magnetite, and chlorite with residual garnet. Mag. 113 diams. 

 Photo, G. S. Sweeting. 



Fig. 2. Siliceous vein crossing the Micaceous-Magnetite-Schist, No. 933. The 

 dark central area in the vein is felspar. Mag. 22 diams. crossed nicols. Photo, G. S. 

 Sweeting. 



Fig. 3. No. 889, Magnetite-Garnet-Schist, showing parallel line development 

 with garnet. Mag. 25 diams. Photo, G. S. Sweeting. 



Fig. 4. Magnetite-Garnet-Gneiss, No. 149, containing pleochroic halos around 

 radioactive inclusions in biotite. Mag. 48 diams. Photo, G. S. Sweeting. 



Fig. 5. No. 102, a rock composed of garnet, quartz, magnetite, and apatite. 

 Mag. 24 diams. Photo, G. S. Sweeting. 



Fig. 6. No. 252, Tourmaline-Magnetite-Gneiss, with numerous perfect pleo- 

 chroic halos in cordierite. Tourmaline (dark with cross cleavage), sillimanite (fibrous) 

 and magnetite (black) can also be seen. Mag. 34 diam. Photo, G. S. Sweeting. 



[Two plate*. ] 



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