546 HENRY B. KUMMEL 
market, owing to a sharp curve in the trap sheet by which it 
crosses the beds nearly at right angles, the Lockatong beds occur 
on both sides of the trap, their upper limit being about 1760 
s 
Ty 
ys. 
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v : 
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A 
Plainfield 
Frenchtown\\# 
il Crystallines 
Paleogoic 
F223] Stockton 
Lockatong 
(a) Brunswick 
peste Trap 
= Cretaceous Lambertville 
Faults 
a si . [ z 
---- Trap Dikes P = , 
SUBDIVISIONS OF THE NEWARK-SYSTEM : CS 
AND 
PRINCIPAL TRAP AREAS 
BY HENRY B. KUMMEL 
Scale of Miles 5 
Sytstown 
= 
SIN gers ome eas dO) 
J AR Prince Del. 
feet above the latter. The plateau, which owes its elevation to 
the hardness and durability of the argillite flagstones and trap, 
is terminated on the northeast by the fault. 
The most extended outcrop of the Lockatong beds occurs on 
the Hunterdon plateau, in the region known as “the Swamp.” 
As shown on the accompanying map the width of the outcrop is 
greater here than elsewhere due to diminished dips, 10° to 13° 
here as against 15° to 20° on the Sourland plateau, and the belt 
