146 



NEW YORK STATE MUSEUM 

































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Fig. 1 





























































































































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Sr 





































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Fig. 2 































































































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Grenville limesfene or other 

 relatively weak rock. 





Hr 



ecambric gram-hc 



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SCALE 









Grenville gneisses - 



600 FT. 







distinctly st ra hfi ed 



















































East-west structure sections through the western side o\ Chimney mountain 

 (looking northward) 



Fig. 1 Showing essentially the condition of things not long before the 

 development of the greal rift. The position o\ a prominent joint plane is 

 indicated in the Grenville gneisses. 



Fig. 2 Showing essentially the condition of things immediately alter the 

 development of the greal rift due to breaking awaj of a large block from 

 the parent ledge oi Grenville gneisses. 



Fig. 3 Showing the present condition after some weathering and the ac- 

 cumulation of large, angular rock fragments at the bases of the steep slopes. 



