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loped with change of chemical composition of the rock or are 

 the result of pegmatization in the manner described by Mr. 

 Howchin. Between these eyes are long bands of quartz and 

 brown mica, with smaller eyes of quartz. Microscopically it 

 is almost identical with 593 (the Normanville Gorge rock). 

 The quartz "eyes" are about 5 mm. in length and 

 half that in width, but their outline is very irregular. They 

 are generally, however, composed of one grain only, usually 

 very highly strained. Inclusions of liquids in small cavities 

 are exceedingly common ; of felspar and sericite rarer. The 

 felspar "eyes" are up to 2 cm. in diameter, and are of micro- 

 cline. They are also somewhat strained, and contain inclu- 

 sions of quartz. They have been broken, and fine-grained 

 quartz has recrystallized in between the broken portions. An 

 excellent example of this is shown in fig. 4. The ground- 



Fig. 4. — Quartz crystallizing between the nortions of a frac- 

 tured porphyroblast of microcline, which also contains quartz 

 poikilitically. Mi, microcline; Q, quartz; Se, sericite; Bi, biotote; 

 p, perthite. 



