660 REVIEWS 
Another point of interest and significance is found in the fact that 
the conglomerates do not occupy a distinct horizon, but that each of 
the three series in turn becomes conglomeratic as the border of the 
system is approached. Incidentally it may be inferred that the north- 
western extension of the system was never much greater than now, 
since the shore phase of each series is represented along the present 
border. 
The relations of the igneous rocks of the system also receive much 
more systematic discussion than in any previous publication. Several 
small areas of igneous rocks (dikes) heretofore unmapped have been 
located. While the previous conclusions as to the intrusive character of 
some of the trap sheets and the extrusive character of others are con- 
firmed, the evidence on which these conclusions rest is so fully 
detailed, and is in itself so decisive, that further discussion of this point 
is not likely to arise. 
Many of the principal structural features of the Newark system 
have long been known, but no previous student of these formations 
has worked out the details of the structure with anything like the full- 
ness shown by the present report. The general monoclinal structure 
of the system (strike N. 30° to 50° E, and dip 13° or 15° to the north- 
west) is found to be affected by several broad, gentle flexures, and by 
a few sharply marked folds, especially in the vicinity of the intrusive 
sheets of trap and along the greater fault lines. The positions of these 
flexures are given and their effects on the topography, where beds of 
unequal resistance outcrop, are pointed out. Even among the gentle 
folds of the system the axes of flexure sometimes depart from hori- 
zontality because of still gentler cross-folds, showing that the forces 
which deformed the beds were not confined to one direction. 
The beds of the Triassic system have long been known to be 
faulted, but not until now have these faults been worked out in detail. 
Of the two major faults, one (the Flemington fault) was known before 
Dr. Kiimmel’s studies began, while the other (the Hopewell, fault) was 
discovered by him. Both these faults have a throw of several thousand 
feet, and each causes the repetition of the outcrop of each of the three 
series of the system. Besides these two principal faults, displace- 
ments are believed to exist along the northwest border of the system 
at more than one point. 
Of minor faults there are many. Something like fifty are described, 
and many figures are given showing in a graphic way the evidence on 
