30 



NEW YORK STATE MUSEUM 



It is interesting to note that the strike of the Trenton fault and 

 fold, as well as the strike of a number of low folds within the region 

 corresponds closely to the strike of the Precambric foliation planes. 

 This shows that the pressures so different in intensity and which 

 produced both sets of phenomena so widely separated in time, 

 acted in the same direction. 



Contorted strata within the Trenton 1 



Excellent examples of highly folded or contorted strata between 

 nonfolded strata may be seen along the sides of the gorge at Tren- 

 ton Falls. Dr J. M. Clarke has called the writer's attention to a 

 similar case of interbedded contorted limestones described by Sir 



I I i i a 



Fig. 4 Highly folded and broken strata between nonfolded 

 strata as seen along the footpath opposite the crest oi High 

 falls. Drawn from nature 



William Logan 2 and occurring on the Forillon peninsula of Gaspe, 

 along the Gulf of St Lawrence. According to Clarke 3 these con- 

 tortions lie in the Cape Bon Ami beds of the lower Devonic. 



At Trenton Falls the folded beds lie at two distinct horizons 

 within the Trenton limestone. According to Prosser and Cumings 4 

 who have made careful measurements of the thickness of the lime- 

 stone at this locality, the base of the lower contorted zone lies 144 

 feet below the top of the Trenton. This zone is from 4 to 6 feet 

 thick and is visible only at the crest of the lower part of High fall 

 and in the upper end of the gorge near Prospect where the strata 

 are highly inclined [see pi. 8]. Using the measurements of Prosser 

 and Cumings the base of upper folded zone lies about 65 or 70 feet 



1 See paper by the writer in Jour. Geol. 1908. 16:428-33- 



2 Geo 1 .. Can. 1863. p. 391-92. 



3 N. Y. Mus. Mem. 9. 



4 N. Y. State Geol. 15th An. Rep't, p. 615-27. 



