CHAPTER IV. 
FORMATIONS OF SILURIAN AGE. 
SHAWANGUNK 
GREEN POND CONGLOMERATE. 
The formation next above the Hudson River slates is best exhibited 
in the Kittatinny mountain, where it forms the crest of the ridge, 
dipping away to the northwest. The northward extension of this 
mountain in New York is known as the Shawangunk mountain, and 
in 1840 this formation was named the Shawangunk grit by Mather.* 
The name Oneida was applied later by Vanuxem,+ in 1842, and has 
been the usual designation of the formation in New Jersey, but 
Mather’s name has priority, and it seems best to retain it. 
The formation consists of beds of coarse quartz conglomerate, the 
pebbles usually being white or yellowish in color, with a gray or red 
matrix. Nowhere in New Jersey has the contact between this forma- 
tion and the subjacent Hudson River beds been observed, but in the 
New York, Lake Hrie and Western railroad cut west of Otisville,f 
in New York, the contact is well exposed, and the higher formation 
is seen to rest unconformably upon the lower. The thickness of the 
formation in the Kittatinny mountain has been estimated by Dr. 
Kiimmel to be 1,500 to 1,600 feet. . 
In the Green Pond mountain region a conglomerate very similar to 
that of the Kittatinny mountain forms the crests of Green Pond, 
Copperas and Kanouse mountains, and rests unconformably upon the 
subjacent formation, which is sometimes the Kittatinny limestone 
and sometimes the Pre-cambrian crystalline rocks. 
No organic remains have been detected either in the Shawangunk 
conglomerate of the Kittatinny mountain or in the Green Pond con- 
glomerate, but the identity of the two formations seems to be assured. 
Both formations are very similar lithologically, both rest unconform- 
ably upon the underlying formations, both are succeeded by similar, 
*N. Y. Geol. Sury., Fourth Ann. Rep., pp. 246-255. 
+ Geol. N. Y., pt. IIL, p. 75. 
{ Fifteenth Ann. Rep. N. Y. State Geol. for 1895, vol. I., plate XX., opposite p. 
444. 
