REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1900 r51 



South along the 7 miles of railway between Ohildwold' and 

 Horseshoe, rock cuts are frequent, and all show no other rock 

 than quite typical augite eyenite, though mostly quite thoroughly 

 gneissoid. About Pleasant lake, 3 miles from Childwold station, 

 exposures are very numerous, and a southerly spur of Arab moun- 

 tain breaks down in tremendous cliffs of this rock to the east: of 

 the track. From this point another crosscut to Tupper lake w^as 

 made, by way of Bridge Brook pond, and here aleo nothing but 

 syenite was seen for the first half of the distance. Beyond, it 

 becomes somewhat inyolved with granite, specially at the west 

 end of the pond. Such granite is frequently associated with the 

 syenite in the Tupper lake vicinity and \\dll be again reverted to. 



The last eyenite seen going south along the railway (1035) was 

 found in the woods i mile west of the track and 1 mile north of 

 Horseshoe. About Horseshoe somewhat different rocks appear, 

 and in a crosscut through the woods from Horseshoe to the south 

 end of Tupper lake no syenite was seen in mass. But between 

 Childwold and Horseshoe the syenite crosses the railway in a 

 belt 6 miles in width from north to south. Its extent farther 

 west has not yet been determined, but it can not go far, since 

 Smyth's work about Cranberry lake shows that it dies out before 

 that point is reached. 



Summary of section. The above detailed observations show 

 that the augite syenite w^hich is exposed widely about Big Tupper 

 lake, extends solidly west through the woods to the railway, 

 which it crosses in a belt 6 miles in width, d-ying out not far to 

 the west; that to the north of it, along the Raquette river, is a 

 belt of red and green gneisses increasing in breadth westward. 

 The green gneisses in this belt much resemble some of the more 

 gneissoid phases of the augite syenite, and it will be later shown 

 that they are closely related chemically. They are moreover 

 confined to the border zone, and only the associated granitic 

 gneisses persist. The latter cut the green gneisses intrusively 

 and are clearly somewhat younger. If the green gneisses have 

 no connection with the syenite, and the whole represents an older 



