EXPLANATION OF PLATES 

 PLATE IL 



Figure 14. 



Microphotograph of quartz-zircon groups in the fine-grained portions of 

 the pegmatite pipe in the Ballou quarry. In the lower right-hand quadrant 

 one of these aggregates is seen with a well developed crystal outline. In this, 

 the dark areas are zircon, the white, quartz. The surrounding material is 

 quartz. Other groups above and to the left. 



Crossed-nicols. Magnification about 120 diameters. 



Figure 15. 



Microphotograph of fine-grained rock lying just below and slightly east of 

 the large pocket in the Fallon quarry pegmatite. Shows small lath-shaped 

 albite crystals scattered through, and lying about, microcline grains. The 

 smooth areas are quartz. Just between the two lower quartz grains is one 

 of aegirite, also penetrated by the albite. 



Crossed-nicols. Magnification about 120 diameters. 



