Hies — Geology of Okange County. 



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and zinc has been made at the summit <>t' the ridge above Guymard, also at 

 the summit west of W. C. Tymeson's house, three-quarters of a mile north of 

 Otisville. 



The unconformity between the Oneida conglomerate and Hudson river 

 slates is finely seen in the railroad cut, half a mile west of Otisville, and also 

 on the north side of the road from Finchville over the mountain to Guymard. 

 This unconformity indicates an uplift at the close of the Hudson river period, 

 and erosion of the surface of the Hudson river deposits. Considerable 

 folding also took place. The Oneida conglomerate and Medina sandstones 

 were deposited during a period of increasing submergence. 



In the lower portion of the Medina formation there are about forty feet 

 of coarse quartz conglomerate, with interbedded layers of shale. This passes 

 upward into the Shawangunk grit, which is extensively opened in the 

 quarry west of Otisville. The rock dips 30° W., and strikes N. 40° E. 

 It is a fine-grained, bluish grey, gritty quartzite, in layers four to twelve 

 inches thick, and of very constant character. In the topography it create s 

 steep wooded slopes covered with a stunted growth of trees. The grit 

 has a thickness of about 750 feet. It passes upward into sandstones and 

 shales of Medina age. The sandstones are seen on the western slope of 

 the ridge along the road from Finchville to Shin hollow, and a short distance 

 before reaching the railroad track. They are thin-bedded red sandstones and 

 shaly sandstones in layers from one inch to a foot thick. At times they are 

 micaceous and sometimes have small grains of pyrite, as above Guymard. 

 The strike above Shin hollow is K 40° E., and the dip, 60° W. (Elevation, 

 910 feet A. T.) Along the road across the mountain east of Greenville, the 

 strike is the same, but the dip is 34 Q W. The red sandstones pass upward 

 into greenish grey shales, which are exposed in the railroad cut south of 

 Shin hollow. They are very fissile, and the surface of the thicker and harder 

 layers is covered with reticulated cracks. 



West of Shawangunk mountain is a depression, followed by the Helder- 

 berg ridge holding the Helderberg limestones and the Oriskany and Esopus 

 -formations. The Helderberg ridge, with its subordinate crests and ridges, 

 is parallel to the Shawangunk mountain, from Port Jenis to the northern 

 limits of the county, and beyond. The structure of the ridge is that of a 

 monoclinal, with a system of gentle transverse flexures, each hill representing 

 a low anticlinal, while the roads which cross the range lie in the synclinals. 



All the rocks in this ridge have a prominent cleavage, which becomes 

 more marked with the ascent. in the series, and the bedding is often totally 



