GEOLOGICAL SECTION OF NEW JERSEY 359 
Poxino Island shale-——The top of the High Falls shale in New 
Jersey is everywhere buried by glacial drift which also conceals the 
beds immediately superjacent. ‘The next recognizable formation is 
the Poxino Island shale, a buff or greenish calcareous shale in thin 
layers and non-fossiliferous so far as known. Its outcrops along the 
base of Wallpack Ridge in the upper Delaware Valley are few, small, 
and widely separated, and very little is known regarding it. In the 
adjoining portion of Pennsylvania it is reported to be 200 feet in 
thickness, and to rest on a thin limestone formation which in turn 
rests on the High Falls shale. It is not known to occur in the Green 
Pond Mountain region. 
Bossardville limestone—A_ fine-grained, compact, bluish-gray, 
banded limestone, known as the Bossardville limestone, lies conform- 
ably upon the Poxino Island shale in Wallpack Ridge. It increases 
in thickness from 12 feet at the New York state line to about too feet 
where it crosses the Delaware River into Pennsylvania. Owing to 
_its marked banding it was for many years known as the “ Ribbon” 
limestone and was correlated by Cook and later geologists with 
the Ribbon or Manlius limestone at Rondout, N. Y. In reality it 
lies below the Manhus limestone. It is only sparingly fossiliferous 
but is immediately succeeded by a series of beds containing a well- 
defined Salina fauna. It has not been recognized in the Green Pond 
Mountain belt, but this may be from lack of exposures. 
Decker Ferry jormation.—Under the name Decker Ferry formation 
a series of beds has been described, which are chiefly limestones at 
the north and calcareous sandstones at the southwest. Their thick- 
ness is 52 feet at the Nearpass quarry near Tri-States where the 
section can be accurately measured. Thin bands of more or less fissile 
green shale separate the limestone beds. A thin band of red, crystal- 
line, highly fossiliferous limestone occurs about the middle of the 
series and is a striking feature. The lower 42 feet of these beds as 
exposed at the type locality are correlated’ with the Wilbur limestone 
(the so-called “ Niagara” or “Coralline”’ limestone of Hall and other 
authors) and the “black cement” beds, i.e., the Salina “water 
lime” of the Rondout section of New York. These form the top of 
the Salina group, the base of which in New Jersey is the base of the 
t Hartnagle, New York State Museum Bulletin 60, p. 1152. . 
