366 HENRY B. KUMMEL 
species of fish, and a small crustacean being the chief elements of a 
meager fauna. 
Three divisions have been made on lithologic grounds: at the 
base the Stockton beds, comprising arkosic conglomerates and sand- 
stones with some shales; above these the Lockatong beds, consisting 
of black shales, hard, massive, dark argillites, flagstones, and occa- 
sional very impure, thin, limestone layers; and at the top a great 
thickness of very soft argillaceous red shale, the Brunswick beds, 
which are more typical of the whole series than either of the other 
groups. Massive conglomerates at various points, chiefly along the 
northwest border adjoining the Highlands, replace these types at 
various horizons. Ripple marks, mud cracks, rain-drop impressions, 
reptile footprints are not uncommon in the finer shales, and cross- 
bedding, plunge and flow structure, and rapid variations of texture 
are characteristic of the coarser beds. 
These sediments have been regarded as (1) deposits in broad 
shallow estuaries in which subsidence went on pari passu with 
deposition; (2) lake sediments; (3) sediments in orographic valleys 
made by rivers of enormous width; and (4) subaérial stream deposits 
on a piedmont plain fronting a newly uplifted crystalline foreland 
from which numerous short but vigorous streams derived the sedi- 
ments which were deposited in coalescing alluvial fans. Occasional 
downward movements of warping or faulting gave opportunity for 
local thickening of the deposits along the belts affected. The latter 
view is perhaps the more likely, although the first still has its adherents. 
Four or more periods of eruption at considerable intervals gave 
rise to three great sheets of basalt each of which is conformable 
to the beds on which it rests, and each of which was buried by con- 
tinued sedimentation. The intrusion of a thick sill of diabase 
obliquely across the strata occurred toward the close of sedimenta- 
tion. Uplift accompanied by northwestward tilting and normal 
faulting terminated the deposition of these beds, caused the displaced 
strata to be beveled off across the upturned edges, revealing the edges 
of the buried basalt and diabase sheets, and brought up again the 
crystallines which in adjoining states, and to some extent in New 
Jersey, skirt the southeast border. The constructional topography 
due to these orographic movements was largely, if not entirely 
