296 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



DEVONIAN FORMATIONS IN THE GREEN POND MOUNTAIN AREA. 



Eanouse sandstone. — The Kanouse sandstone, the lowest Devonian formation of the 

 Green Pond Mountain region, is a thick-bedded, fine-grained conglomerate below and a greenish 

 sandstone above, having a thickness of about 215 feet. Although fossUs are not rare, yet as 

 a rule they are obscure and many of them are so greatly distorted that their identification is 

 impossible. So far as recognized they indicate an Onondaga fauna, and these beds may be 

 interpreted as the shoreward correlatives of the Onondaga limestone. It is the formation 

 which in the New Jersey Geological Survey reports has been called the Newfoundland grit. 



Its outcrops form a narrow belt parallel to the Decker Ferry limestone but separated 

 from it by a narrow interval. ' In the upper Delaware Valley, as noted above, there are seven 

 formations aggregating nearly 900 feet in thickness between the Decker Ferry and the Onon- 

 daga. In the Green Pond Mountaia region none of these has been recognized and, if present 

 at aU, it can be only in very attenuated form. 



Pequanac sTude. — The Kanouse sandstone apparently grades upward into a black and 

 dark-gray thick-bedded slaty shale (the "Monroe" shale of Darton and others). Cleavage 

 is usuahy strongly developed so that the bedding planes are not always readily discernible. 

 The thickness is estimated at 1,000 feet. This formation is probably conformable upon the 

 Kanouse sandstone, but the contact has nowhere been observed. It contains a somewhat 

 meager fauna, among which, however, is the characteristic Hamilton species Tro'pidole'ptus 

 carinatus, so that its reference to this period is beyond question. 



Bellvale sandstone. — The BeUvale sandstone is scarcely more than a continuation of the 

 Pequanac shale, but the beds are coarser and more sandy. The average thickness is estimated 

 at 1,800 feet. The few fossils found are all Hamilton species. 



STcunnemunlc conglomerate. — ^The Bellvale sandstones grade upward into a coarse purple- 

 red massive conglomerate, the white quartz pebbles of which are sometimes 6 or 7 inches in 

 diameter. Beds of red quartzitic sandstone alternate more or less frequently with the con- 

 glomerate and there are many gradations between the two. It forms the great mass of Bear- 

 fort Mountain in New Jersey and of BeUvale and Skunnemunk mountains in New York. It is 

 the youngest Devonian formation in New Jersey and rests upon beds known by their fossils 

 t,o be of Hamilton age. Whether it is the exact equivalent of the Chemung-CatskUl can not 

 be determined. 



