1889 .] 
381 
[Davis and Wood. 
out on the shales between the parallel trap-ridges. Eastward and 
southeastward, the broad lowlands from north of Paterson to New- 
ark and Elizabeth and thence westward be} T ond Bound Brook, must 
also be refilled ; the chief defining lines here being the Watchung 
ridges on the west, the Palisades on the east and Rocky Hill on 
the south. It may be confidently believed that the last two ridges 
are parts of a single trap-ridge — the edge of a single trap sheet — 
depressed and buried under Cretaceous deposits at its middle about 
New Brunswick, and rising thence northward and south westward 
in accordance with the deformation that the ancient peneplain has 
suffered. No statement can be made as to the extension of the 
old peneplain beneath the cretaceous deposits above referred to ; 
but the geological structure of the region clearly demonstrates that, 
after this part of the plain had been made, it was submerged by a 
transgression of the Atlantic, and buried under detritus from some 
adjacent land. This is considered further in section 19. 
To one who is unaccustomed to the magnitude of the work of 
erosion in fashioning the surface of the earth, it may seem almost 
incredible that so great an amount of material as is indicated by 
the amount of filling just called for should have been worn away ; 
but the more the surface of the world is examined, the more neces- 
sary it is to admit that the land as we see it is carved deep in the 
land as it has been. If evidence is asked for in confirmation of this, 
we need only turn to the vast beds of stratified rocks, twenty to forty 
thousand feet thick in the central Appalachians and as much in 
parts of the Cordilleran region, to discover some of the deposito- 
ries of ancient destructive work of this kind. There may again 
be doubt when one is asked to accept the fact of heavy erosion in 
New Jersey on what may seem at first like imperfect and insufficient 
evidence, as presented above ; but we are persuaded that the more 
the matter is studied, the fuller confidence will be gained that the 
evidence of the crest lines is susceptible of no other interpretation 
than that here adopted. We may later ask what has become of the 
waste carried from the land, first in making the Schooley peneplain, 
and later in roughening it again. 
The reader must guard against making too artificial a concep- 
tion of the smoothness of the Schooley peneplain at the time of 
its elevation. The harder rocks, such as the gneisses and the traps, 
undoubtedly resisted the destructive forces successfully enough to 
maintain rolling elevations above the general surface in the late 
