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the primary strata of the Highlands, it was stated that those 

 formations where they appear in the neighbourhood of Green 

 Pond and Macapin Pond, were overlaid unconformably by a 

 group of much newer date, conceived to have been produced in 

 the middle secondary period. I propose to offer a brief account 

 of the position, structure, and probable origin of these insulated 

 strata. 



Geografliical range. — Tracing these unconformable rocks from 

 New York towards the southwest, they are found to constitute a 

 nearly continuous mountain chain, extending from the western 

 side of Long Pond, past Macapin and Green Ponds, to a point 

 west of Succasunny. From the State line to the Pequannock, the 

 belt consists of a single ridffe, somewhat broken down in some 

 places by denudation — this is known as the Long Pond or Raffen- 

 berg Mountain ; but from the Pequannock southwest for several 

 miles the belt is double, the shorter range forming the Copperas 

 Mountain, and the longer parallel one the Green Pond Mountain, 

 ending north of Succasunny. 



These ridges are for the most part remarkably straight, while 

 their summits arc nearly level. Throughout considerable dis- 

 tances they present a succession of bold precipitous escarpments, 

 facing invariably the east-southeast. The strata dip in all cases to- 

 wards the west-northwest, at an angle which is somewhat varia- 

 ble, but which is usually about 80°. 



The almost perpendicular outline of these ridges on their south- 

 eastern side, the repetition of the same rocks in the two adjoining 

 ranges, and their dipping towards the same quarter, are facts 

 which strongly indicate the existence of one or more extensive" 

 longitudinal dislocations of the strata. We can hardly conceive 

 how a mere denudation of the surface, unaccompanied by a disrupt- 

 ing movement along certain lines, could have given to the topo- 

 graphy of this formation its present peculiar features. 



The Green Pond Mountain terminates in three oval-shaped out- 

 lying hills in the prolongation of the main ridge, separated from 

 each other and from it by transverse valleys or notches ; through' 

 one of which the Morris canal has been carried. A fourth low hill, 

 not precisely in the same line with the others, commences a little 

 south of these and extends longitudinally towards Flanders. It 

 would appear to belong to a different formation from the others, 



