DEVONIAN. 295 



character as to indicate a separate immigration from the exterior into this region." As indicated 

 above, south of Hainesville a thin sandy bed intervenes between the Coeymans limestone and 

 the New Scotland beds and gradually replaces the latter. At Flatbrookville, where these strata 

 cross the Delaware into Pennsylvania, the lower cherty hmestone member of the New Scotland 

 beds has disappeared and the Stormville sandstone contains a fauna characterized by Spirifer 

 tnacropleurus. 



Becraft limestone. — A hard gray cherty limestone overhes the shaly layers of the New 

 Scotland beds, forming a resistant layer which outcrops frequently along WaUpack Kidge. 

 Its entire thickness has never been observed, but it is estimated to be about 20 feet. Its fauna 

 is closely allied to that of the New Scotland beds, a few new forms appearing and a few old ones 

 disappearing. There is also some difference in the proportionate number of individuals of 

 some species, notably of Leptiena rhomhoidalis, which becomes especially abundant. The 

 bed is correlated with the Becraft hmestone of New York. 



Kingston or Port Ewen beds. — A series of strata, nowhere exposed, occupies the interval 

 between the Becraft hmestone and the base of the Oriskany. They are probably shaly beds 

 which easily disintegrate and thus become covered with debris. Their thickness is roughly 

 estimated as 80 feet. The only basis for their correlation is their position, which corresponds 

 to that of the Port Ewen (Kingston) beds of New York. In Pennsylvania, the same beds have 

 been called the Stormville shales by White.^ 



Oriskany formation. — A series of strata, aggregating about 170 feet in thickness, succeed 

 the Port Ewen beds and are referred to the Oriskany. They are for the most part sUiceous 

 Umestones, but the summit of the formation along the southern half of the WaUpack Ridge 

 becomes a sandstone. The arenaceous facies is said to become more marked to the southwest 

 in Pennsylvania and to embr9,ce lower and lower beds until all the strata to the top of the 

 Coeymans limestone are sandstones. The fauna of the Oriskany beds in New Jersey comprises 

 three well-defined faunal zones, the lowest characterized by Dalmanites dentatus, the second by 

 Orhiculoidea jervensis, and the third by the great abundance of Spirifer murcJiisoni. 



In the Nearpass section the beds bearing the Dalmanites dentatus fauna are about 30 feet 

 thick and form the crest of a high ridge which is the southern extension of the "trilobite ridge"" 

 east of Tristates. There is a mingling of Helderbergian and Oriskanian forms in this fauna, 

 and there has been some difference of opinion as to whether these beds should be placed in the 

 Port Ewen or Oriskanj^, but recent workers'* unite in referring them to the Oriskany. 



Esopus grit. — The Esopus grit which overlies the santistones and sihceous limestones of 

 the Oriskany forms the crest of WaUpack Ridge for the greater part of its extent in the State. 

 It is a nearly black gritty rock with well-developed cleavage, which obscures the bedding planes. 

 The fucoid "cauda galh" markings can frequently be recognized on the bedding planes when 

 the latter can be distinguished. Apart from these marldngs fossils are very rare. The average 

 thickness of the formation in New Jersey is estimated to be 375 feet. 



Onondaga limestone. — The Onondaga hmestone overhes the Esopus grit along the north- 

 western slope of WaUpack Ridge. Toward its base the formation is somewhat shaly and there 

 is apparently a rather gradual transition from the grit to the hmestone. The latter is hard, 

 cherty, and regularly bedded in layers ranging from 3 inches to 1 foot in thickness. The beds 

 are assigned to the Onondaga on the basis of their position and lithology rather than faunal 

 evidence, since the recognizable forms are not sufficiently characteristic for close correlation. 



Marcellus shale. — FissUe black shale, referable to the M'arceUus, has been reported to 

 occur in New Jersey along the bed of the Delaware River a few nules below Port Jervis, but in 

 recent years the exposures have apparently been buried by sUting up of the channel. This is 

 the highest of the Devonian beds exposed in the State along the Delaware River, but in the 

 Green Pond Mountain area stUl vounger beds occur. 



o Weller, Stuart, New Jersey Geol. Survey, Paleontology, vol. 3, 1903, p. 90. 



6 Second Geol. Survey Pennsylvania, Kept. G6, 1882, p. 131. 



c Shimer, H. W., Bull. New York State Mus. No. 80, 1905, p. 175. 



<i Weller, Stuart, op. cit., p. 96. Shimer, H. W., op. cit., p. 184. 



