NEWARK ROCKS OF ROCKLAND COUNTY, N. Y. 



27 



feet in hight, and at its foot are the long lines of talus, composed 

 of huge angular blocks broken by frost action from the precipice 

 above, and only partially concealed by a few trees. The naked 

 talus slope is also well shown south of Haverstraw near Short 

 Clove. The highest knob shown in the view has an elevation of 



Fig. 2 Weathered trap at Piermont. 



730 feet above the river and 550 feet above the flat at its foot. 

 The base of the trap usually lies a few feet below the foot of the 

 cliff and beneath the upper limit of the talus. 



At the Manhattan trap rock quarry shown in plate 3, just 

 beneath the knob at the right, the contact has been exposed. At 

 the time of my visit, the trap at the south end of the quarry could 

 be seen cutting across the sandstone obliquely downward to the 

 north, a distance of about 35 feet in 60. Thence it followed con- 

 formably the bedding planes and gradually regained its former 

 elevation above sea level, though still at a lower geologic horizon. 



