428 



Report of the State Geologist. 



limestone contains an abundance of- fossils, which are easily obtainable in 

 the limonite pits south of the cross-road." 



The Helderberg rocks probably extend around the Oriskany of Pea hill 

 to the southwest, but there are no outcrops, owing to the heavy covering of 

 drift. 



The Longwood shales at Cornwall are light-colored, thin-bedded quartz- 

 ites in their upper members, and red and green shales in their lower ones. 

 To the east they are underlaid by the Oneida conglomerate. This conglomerate 

 forms another ridge further west. Northeast of Mountainville, the Longwood 

 shales crop out along the road to Orr mills. 



Geology of Deer Park Township. 



Shawaugunk mountain extends across the eastern edge of the township, 

 and separates it from Greenville and Mount Hope townships to the east. 

 Its rounded crest has an' elevation of 1,200 to 1,400 feet, being highest at 

 the northern end of the township. The lowest point in the ridge is west of 

 Otisville, where the Erie railroad passes through. The cultivated eastern 

 face of Shawaugunk mountain is underlaid by Hudson river slates and 

 sandstones, while the steep, wooded western face is formed of sandstones 

 and conglomerates of Medina age. 



The Hudson river formation consists of westwardly dipping shales and 

 red and grey sandstone beds of variable thickness. No fossils were found 

 in them at this locality. These beds underlie the Shawaugunk grit with a 

 slight but constant unconformity. The boundary between the two along 

 the crest of the mountain is generally marked by a swamp, along whose 

 western side the Oneida conglomerate rises as a low cliff. The sheared 

 surfaces give evidence of movement along the contact of the slates and 

 conglomerate. There are, also, along the contact, numerous small fissure- 

 veins bearing lead and zinc intermixed with quartz. The quartz crystals 

 often show a fine zonal structure, due to their intermittent growth. A 

 breccia occurs in the vein at Guymard, six miles northeast of Port Jervis. 

 The fissure vein at this locality is the largest found in the county. It is 

 three to four feet wide and several hundred feet long, and has been exten- 

 sively exploited in former years. It is no longer worked. The vein occurs 

 in Shawaugunk grit, but probably extends down into the conglomerate. 

 The ore consists of galena and sphalerite disseminated through quartz. The 

 quartz crystals often occur in radiating clusters. Another opening for lead 



