Plate 39 



Photomicrograph of no. 24. Annsville phyllite. Taken with crossed nicols, magnification 

 about 25 diameters. 



Showing the typical structural quality of this rock and its principal make-up. The chief 

 features are: a Very bunched distribution of granular aggregate quartz (clear), b Very minute 

 flaky mica giving a streaked structure, c Presence of considerable carbonate. 



Plate 40 



Photomicrograph of no. 24-o. Annsville phyllite. Taken with crossed nicols, magnification 

 about 30 diameters. 



A different field in the same thin section. Showing the nature of the spotted varieties of this 

 rock, a Quartz (clear) _ showing tendency to granulation of large grain, b Mica (large shreds). 

 c Carbonate (rough grains). 



