REPORT OF THE DIRECTOR AND STATE GEOLOGIST 



r35 



perthite. Light red garnets form a very important and a con- 

 stant component. No. 10 has a nest of little eillimanite needles, 

 contained in quartz. No. 11 differs from the other specimens in 

 being a more basic rock and one that lacks quartz almost en- 

 tirely. It is no longer fresh but now presents an aggregate of 

 more or less kaolinized plagioclase and chlorite, the latter of 

 which probably represents original hornblende. Biotite is pres- 

 ent in considerable amount and is relatively unaltered. A few 

 garnets, apatites and titaniferous magnetite complete the miner- 

 alogy. The rock is one that is not at all uncommon among the 

 gneisses of the Adirondacks and probably merely indicates a 

 hornblendic band. 



The general character of these gneisses is not different from 

 many that are widespread in the areas farther north and that are 

 probably sedimentary in their origin. It must be stated that 

 there are no labradorite rocks or evident eruptives at the local- 

 Sty. 



