Ries — Geology of Orange County. 



443 



a third just east of Walden (480). They are probably deeply buried 

 erratics. The strike and dip of the Hudson river formation surrounding the 

 Neelytown limestone is given on the map. 



Geology of Newburgh and New Windsor Townships. 



The relations around the northeastern end of Skunnemunk mountain and 

 Pea hill have already been alluded to. In Newburgh and New Windsor 

 townships the areal geology is briefly thus: A belt of Cambrian limestone 

 in the northeastern corner of Newburgh township, with another belt of the 

 same limestone with some Chazy limestone, west of New burgh. To the north- 

 west and southeast of this area are two small gneiss knobs. The rest of the 

 territory is of Hudson river shale. The Hudson river shales and sandstones, 

 which cover the western and central portions of Newburgh township, are 

 faulted against the Cambrian limestone in the northeastern corner of the 

 township. This fault line crosses the Hudson from Dutchess county, and, 

 entering Ulster county south of Marlborough, passes southward, entering 

 Orange county one mile west of the Hudson river. The limestone has a 

 low western dip, and presents numerous outcrops which form small, rough 

 ridges. Owing to the massive character of the rock, the strike and dip are 

 not always distinct. The line of fault is indicated by a narrow valley, which 

 extends southwest as far as Middle Hope where the stream occupying the 

 valley turns abruptly westward. The western boundary of the limestone 

 extends down to Balmville, and then curves around to the fiver. The slates 

 appear to the south of the limestone, but the drift conceals their exact 

 relations. 



There is a small area of Trenton along the river road, between Newburgh 

 and Roseton, about two and three-quarters miles north of the Newburgh 

 fern-, and at the point where the road comes in sight of the river. The 

 Trenton limestone forms a ledge about 300 feet long and twenty to thirty 

 feet high, on the west side of the road (379). The dark crystalline limestone 

 has a strike of N. 35° E. and dips 40° E. The ledge is about 135 feet above 

 the river. The limestone contains a mass of small encrinal columns and 

 small Cluetetes. The crinoid present in especial abundance is Cleiocrinus 

 magnijicits, a species which had only been previously found in Canada 

 until its discovery by Professor W. B. Dwight at this locality." There 

 are also several other species of Trenton age, viz. : Platystrophia lynx, 

 Pleetamhon lies, etc. 



* A. J. S. (.?), XTX., p. 50. 



