GEOLOGY OF THE SCHROON LAKE QUADRANGLE 4! 



Table 2 Thin sections of syenite, granitic syenite, and granite 



No. 5, by road one-third of ,a mile east of South Schroon; no. 6, quarry 

 one-half of -a mile east-northeast of South Schroon; no. 7, cross-roads 

 one-half of a mile northeast of Muller pond; no. 26, one-half of a mile 

 north-northwest of Bailey pond; no. 28, from granitic syenite area \Y$ 

 miles northeast of Bailey pond; no. 49, southeastern base of Severance 

 hill; no. i, top of hill i l / 2 miles southwest of Taylors on Schroon; no. 2, 

 quarry one-half of a mile a little west of north of Moxham pond; no. 3, 

 lake shore one-third of a mile northwest of Adirondack village; no. 4, 

 i mile east-northeast of Pat pond; no. 8, one-half of a mile northeast of 

 summit of Cobble hill; no. 9, from tongue of granite cutting anorthosite 

 T mile south of Sand pond; no. 25, old road crossing Minerva stream i 

 mile north of mouth of Hewitt pond brook; no. 31, east of brook at north 

 end of granite area 2 miles northeast of Bailey pond; no. 32, little hill just 

 west of Hewitt pond; nos. 34 and 35, southern brow of Cobble hill. 



From table 2 it is seen that microperthite always occurs as the 

 most prominent constituent of the syenite, while oligoclase and 

 quartz are always present in smaller amounts. Orthoclase is more 

 variable and sometimes absent. No. 7 is a fine example of a dis- 

 tinctly basic or dioritic facies of the syenite. Nos. 26 and 49 show 

 reaction rims of garnet around magnetite. No. 31 is highly granu- 

 lated along some zones parallel to the foliation in the thin section. 



Description of granite and granite porphyry. The granite and 

 granite porphyry are regarded as differentiation facies of the great 

 Adirondack syenite-granite series. There are many places where 



