PROS8ER] ULSTER AND DELAWARE R. R. SECTION. 51 
The Haliserites of Lanesboro, Pa., also occurs in this shale. 
Along - the quarry road, lower than the quarry, are exposures of red 
arenaceous shale. Ledges of moderately arenaceous shale occur in the 
upper part of the village and also along the hill on the western side 
of the highway, 1 mile north of Olcott's hotel, but no fossils were found. 
It seems that the fossiliferous rocks of the Hamilton and the lower 
part of the Portage are covered by the drift which has tilled up the 
old river channel in the region of Summitville. At least no expo- 
sures were found containing fossil shells. 
SECTION ALON(l THE ULSTER AND DELAWARE RAILROAD. 
After an examination of the rocks in the Summitville region, the 
next section crossing the Devonian formations is 25 miles to the north- 
east, in the vicinity of Kingston. 
At Eondout, on the Hudson River, are exposures of Hudson shales 
and sandstones which extend from part way up the bluff to near the 
-entrance of the quarries in the cement rock. This is a region of decided 
interest in respect to the stratigraphic geology, since most of the geol- 
ogists who have studied it regard the Upper Silurian as resting 
unconformably on the Lower Silurian, while some consider it a fault. 1 
On the bluff above the Ulster and Delaware Railroad station in Rond- 
out are good opportunities for studying the relations of the Hudson 
shales and sandstones to the overlying limestones. Along the West 
Shore Railroad south of Kingston are numerous exposures of the lime- 
stones and this is an excellent locality to work out the folding as has 
been so admirably done by Prof. Davis for this, and the same series of 
formations, farther north. 2 
iFor the more important papers see -J. G. Lindsey, who described the rocks at the Rondout cement 
quarries, Poaghkeepsie Soc. Nat, Sci., Proc, n, 1879, pp. 44-48; T. N. Dale, " The Fault at Rondout," 
Am. Jour. Sci., Vol. xvin, 1879, pp. 293-295. On p. 294, figs. 1 and 2 give an excellent representa- 
tion of the position of the Lower Helderberg beds on the Hudson River shales; William M. Davis, 
Bull. Mus. Comp. Zool., Gool. Ser., Vol. I, No. x, 1883, pp. 319-323, and on pi. XII see figs. 6, 11, 14, 
and 15, which give several views of the junction of the Hudson shales with the Coralline and Lower 
Helderberg limestones, while in tho text is a complete review of all the literature in reference to this 
structure at Rondout. 
Prof. Davis contributed a paper on " The Nonconformity at Rondout, N. V.," to the Am. Jour. Sci., 
3d ser., Vol. XXVI, 1883, p. 389, with a ma]) on p. 391, showing the distribution of the different forma- 
tions in the vicinity of Rondout, crossed by cross-sections, showing the stratigraphic structure of 
that region. In referonco to tho exposures in the bluff near the cement quarries at Rondout, Prof. 
Davis says: "The Hudson River rocks wore upheaved, oxposed to orosivo forces, presumably of the 
ordinary subaerial kind, and then stibmerged to receive the later formations on their worn edges. 
This is most excellently shown in tho old quarry in the hill overlooking Rondout, where the contact 
line has been perfectly exposed for 10 feet or more; a fair inference of nonconformity can be made 
out at several other points along the slope" (pp. 392, 393). While in a later paper the professor, 
referring to Rondout, says, " there is a strong unconformity. * * * The contact could not have 
been made by a fault; it was a distinct unconformity " (Bull. Geol. Soc. Am. Vol. r, 1890, pp. 354, 
355). 
2 See paper on the folded Helderberg limestones east of the Catskills, "Bull. Mus. Comp. Zool., Geol. 
Scries, Vol. I, 1883, p. 311 ; and in particular see PL xui, which gives a map of " The folded Helderberg 
limestones in Greene County, X, V.," crossed by fifteen sections showing the geologic structure of the 
region. Also a paper by the same author, entitled "The Little Mountains east of the Caljkills," 
A-ppalachia, Vol. in, 1832, pp. 20-33, with Plate i. giving amap of the region, a series of block-sections, 
general section of the Little Mountain belt, section from tho Catskills to the Hudson, and a scries of 
seven special sections. 
