DETAILS OF THE SECTIONS 489 



Overlying it are 329 feet of greenish and buff shales, and shaly limestones 

 which I. C. White calls his Upper Salina, but which also must be referred 

 to the Lower Monroe. White reports these beds unfossiliferous, but I 

 have seen indications of fossils in some of them. The series is succeeded 

 by Lewistown limestone, the lower part of which is of Upper Monroe age. 

 Southwestward along the strike the Bloomsburg red shale is less uniform 

 in character. In the Logan section (Mifflin County) several beds of 

 olive shale 5 feet or more in thickness are found intercalated in the red 

 beds, which still maintain a thickness of 432 feet. In the Orbisonia 

 section the red beds are less than 400 feet thick. Finally, in Blair 

 County, the extreme western exposures, less than a hundred feet of the 

 red shales occur interpolated with many layers of gray shale and some 

 limestones. Another series of red beds occurs a hundred feet below, 

 showing similar alternation. Limestones and shales separate the two 

 series and thin-bedded limestones and shales succeed them, capped finally 

 by the Lewistown limestone with Upper Monroe fossils. The whole series 

 is probably referable to the Monroe. There are about 460 feet of mixed 

 strata between the Clinton iron ore and the Lewistown limestone. 



Other Salina beds of New York. — Turning now to the north and 

 northwest, we find that along the Shawangunk range the red beds slightly 

 overlap the conglomerate. They are alternating red and green shales 

 and sandy beds, and are generally known as the High Falls shales. Their 

 thickness does not exceed 91 feet, and they are succeeded by the Binne- 

 water sandstone, a quartzose sandstone sometimes slightly reddish and 

 averaging 38 feet thick.* Above this come the limestones of the late 

 Upper Monroe — the Wilbur, averaging 2 to 6 inches; the Eosendale, 15 

 to 20 feet; Cobleskill, 14 feet; Eondout, 20 feet, and Manlius, 50 feet, 

 bringing us to the top of the Siluric. The limestones overlap in the 

 northern Helderbergs. 



Throughout the greater part of the State of New York the Salina be- 

 gins with the Vernon red shale, except where, as at Rochester, the Pitts- 

 ford shale forms a transition formation from the Magaran below. The 

 Vernon shale varies from 150 feet in the type locality to 400 or more in 

 central New York. In the typical outcrop in the town of Vernon near 

 Clinton, New York, it comprises 135 feet of dull red shale 1 unstratified 

 and with green spots scattered through the mass. It is separated by 10 

 feet of light greenish shale from the underlying Niagaran limestones and 

 by 5 feet of similar shale from the succeeding dark Cam ill us shale. At 

 Syracuse, where the Vernon shale is Wr> feel thick, it is succeeded by the 

 salt beds, this being the general order within the State. 'Thin sections 



♦Shaft 4, Rondouf syphon, hoard wain- supply record. 



