96 NEW YORK STATE ^^lUSEUM 



oblique angle. Such conditions are especially notable south of the 

 Highlands where the Hudson cuts at a low angle across the ends 

 of a succession of complex folds of the crystalline metamorphics 

 for 30 miles to New York city. But this is true only of the east 

 side of the river. The west bank is an almost unbroken uniform 

 escarpment of the Palisade diabase intruded sheet underlain by 

 Newark sandstones, which if laid down upon a pretty well planed 

 Pretriassic surface might easily control the Hudson, and which 

 would not differ from its present course. 



The most evident exception to this is the course of the river 

 from Ploboken to Staten Island. Instead of following the line of 

 contact between the crystallines and Triassic formations, the river 

 cuts through the crystallines leaving large masses of serpentine 

 and associated schist on tlie west side. This together with the 

 behavior of the river in cutting across the strike farther north 

 near the Highlands is believed to strongly favor the fault theory 

 of location especially south of the Highlands. The same condi- 

 tions would be favorable to the development of- a narrow gorge 

 and perhaps a very deep one rapidly eroded along the crush zone 

 of the fault. 



From the northern entrance to the Highlands to Haverstraw bay, 

 where the Palisades are reached, the stream course is not by any 

 means straight, but shifts from longitudinal structure to cross 

 structure alternately in a zigzag manner. North of the Highlands 

 the course is more direct again. On the whole the present explora- 

 tions have added little to the facts bearing upon this question. 

 P^aults crossing the river are common and easily recognized. Oc- 

 casionally one appears to pass into the river gorge at a very small 

 angle and not reappear. In a few places, especially in the High- 

 lands, the course does not seem to be consistent with the hypothe- 

 sis of a large fault line. It is to be expected that further work at 

 the Hudson river crossing will add materially to the facts relating to 

 the structures within the gorge. 



