GEOLOGICAL SECTION OF NEW JERSEY 365 
and of Bellvale and Skunnemunk mountains in New York. It is 
the youngest Devonian formation in New Jersey and rests upon beds 
known by their fossils to be of Hamilton age. Whether it is the exact 
equivalent of the Chemung-Catskill cannot be determined. 
STRUCTURE OF THE PALEOZOIC FORMATIONS 
The Paleozoic rocks have the northeast-southwest structure lines 
characteristic of all parts of the Appalachian province, due primarily 
to a system of folds and faults whose trend is in that direction. The 
folds are rarely symmetrical, southeastward dips being usually less 
steep than northwest dips, so that the axial planes are inclined to 
the southeast. ‘The folding took place during the Appalachian revolu- 
tion and is most marked in the beds farthest southeast and diminishes 
rapidly to the northwest. Some overthrust faulting occurred during 
the folding, so that now isolated masses of Kittatinny limestone rest 
upon the Martinsburg shale. ‘The more conspicuous dislocations, 
however, are due to nearly vertical faults parallel or oblique to the 
axes of the fold, by which the northwest side has been usually uplifted 
relatively to the southeastern. ‘These faults are referred to disturb- 
ances occurring at the close of the Triassic sedimentation. 
TRIASSIC SYSTEM 
The Mesozoic era is represented by formations referable both to 
the Triassic and to the Cretaceous systems. The Triassic rocks 
occupy a broad belt southeast of the Highlands and extend across 
the north-central portion of the state from northeast and southwest, 
their southeastern margin being approximately a line drawn from 
Trenton to Jersey City. They comprise both sedimentary and igneous 
rocks, the former chiefly shale, the latter extrusive basalt and intrusive 
diabase. ‘They rest unconformably upon the early Paleozoics and 
pre-Cambrian crystallines and along their southeastern margin they 
are in part overlaid conformably by beds of Cretaceous age. The 
structure is monoclinal, the strata being inclined at low angles to 
the northwest, but locally broad, shallow folds have been developed. 
The beds are cut by many nearly vertical normal faults, the amount 
of dislocation varying from a few inches to several thousand feet. 
The rocks are sparingly fossiliferous, footprints of reptiles, a few 
