REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1900 r53 



the variations to which the rock is subject. This syenite area is 

 followed to the south b}' a belt of syenite involved with granite, 

 which runs down the w^est shore of the lake for some little dis- 

 tance. On that shore, just opposite the south end of County Line 

 island, is an exposure consisting mainly of red granite, but with 

 some green syenite gneiss also. The granite m of the coarse type, 

 with long quartz spindles and wholly free from dark silicates, 

 which is often fcuni associated with the syeLite. Here it distinctly 

 cuts the syenite intrusively, the syenite being present only in 

 wedge shaped horses and smaller fragments surrounded by the 

 granite. Furthermore, it maintains its usual structure and grain 

 throughout, whereas the granite becomes quite fine grained in a 

 narrow zone about it, whose breadth is rudely proportional to the 

 size of theinclusions, and varies from a few inches up to 2 feet. 



Farther south along the west shore the rock becomes less 

 typical syenite and much cut out by various granitic gneisees. 

 This same sort of a zone seems to surround the syenite on all 

 sides. Other rocks begin to appear in it, notably the spindle 

 granite and its finer grained contact phase. The syenite itself 

 becomes more acid and grades into an augite granite which has 

 the srtructure and aspect of the syenite rather than that of the 

 spindle granite. Considerable masses of syenite often occur in 

 this border zone. For example, in ascending Mount Morris from 

 Moody, the syenite is left behind as the summit is neared and 

 only granite appears, followed again by syenite at the summit. 

 Thence south into Litchfield park, the syenite comes in again, 

 unbroken syenite occurring all around Lake Madeline, running 

 into the mixed rocks on all sides. 



In the woods between the upper end of Tupper lake and Horse- 

 shoe station, a distance of some 5 miles, the few exposures found 

 for the first half of the distance are of the mongrel gneiss, which, 

 while having considerable resemblance to the augite syenite, is 

 not typical for that rock and is considerably involved with 

 granitic gneiss. On the south shore of the pond a gneiss of wholly 

 different relationships appears in a narrow belt which extends 

 south from the pond to Bog river and possibly beyond. The out- 



