Ries — Geology of Orange County. 



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Warwick. Here it is a very hard, massive rock with an abundance of cherty 

 layers and broken by irregular vertical joints. The dip is very low to the 

 northwest. Half a mile southeast of Mapes Corners is Mount Lookout. 

 This is made up entirely of Cambrian limestone and affords one of the 

 best exposures in the county. The upper beds are somewhat coarse and 

 sandy, while the lower ones are fine-grained and less siliceous. They all 

 dip slightly to the northwest. Most of the limestone is very hard and some 

 of the layers half-way up the hill have siliceous laminae which stand out 

 prominently on the weathered surfaces. Quartz crystals are not uncommon 

 in the cavities of the rock. There are evidences of fossils in some of the 

 coarser layers from the summit of the hill, but no good specimens were found. 



Southeast of the hill and opposite a farmhouse on the main road is a 

 ledge of very cherty, moderately coarse limestone. The thickness of the beds 

 in Lookout mountain is fully 200 feet. This hill is in the main belt of lime- 

 stone, whose most eastern limit is west of the upper end of Grlenmere lake. 

 There the slate and the limestone are separated by a narrow ravine, the lime 



Mr. Eve 



FloURE 3. Section from Mount Adam to Stone Bridge. 

 Or., Granite; W. L., White limestone; B. L., Blue limestone; H. R., Hudson river slates; 



H., Helderberg limestone. 



stone forming a ledge on its western side. At this point (97) the two are 

 about seventy-five feet apart, but a few hundred feet farther south on the 

 west side of the road, they are within six feet of each other. The limestone 

 here dips to the east and is overlaid unconformably by the slate, though an 

 actual contact is lacking;. 



The Hudson river slates extend southward across Warwick township 

 in a wedge-shaped area which is about five miles wide at its upper border 

 and thins out at a point about one and one-half miles northwest of New 

 Milford. The)' rarely afford good exposures, but an excellent one is seen on 

 the road from Warwick to Edenville. 



One mile west of Stone Bridge, is a small area of Helderberg limestone 

 (500) resting unconformably on the blue cherty Cambrian limestone. The 

 Helderberg is a purplish shale containing remains of Bryozoa, Leperditice, 



