304 NEW YORK STATE MUSEUM 



lar. The sandstone shows effects of aUeration by the mineraUzing 

 solutions, becoming charged with iron oxides and in places develop- 

 ing a greenish decomposition product. 



The workings from the former operations consist of several 

 openings on the outcrop some 200 feet below the ridge summit, 

 together with an adit and level 220 feet below the line of outcrop, 

 measured along the vein. This level is about 400 feet long north 

 and south. The ore here dips 35° west and ranges from a few 

 inches to 4 feet in thickness. A second adit was driven into the 

 hill lower down at the level of the mill but did not encounter the 

 vein. 



Assays of ore samples as reported to the writer by Mr Kirby 

 Thomas, consulting engineer for the company, showed an average 

 of 21 per cent zinc, 12.6 per cent lead, a little copper and an ounce 

 or two of silver. The sample represented the rich part of the vein 

 of an average thickness of 18 inches. 



The plans of the company are to mine the ore already in sight 

 and simultaneously to carry on exploration for additional supplies. 

 The milling operations are intended to effect a saving of both lead 

 and zinc. The site of the new mill is close to the tracks of the 

 Ontario & Western Railroad, near the base of the ridge. A 1600- 

 foot aerial tramway will lower the ore by its own gravity from the 

 working adit to the mill. J. MacDonald Mitchell is the engineer 

 in charge. 



At Wurtsboro, to the south of Summitville, is a similar occur- 

 rence of lead and zinc sulphides. It is referred to in the reports of 

 the First Geological Survey as the Shawangunk mine, and Mather 

 states that three solid masses of galena weighing 800, 1000 and 

 1400 pounds were taken from the vein at the time of his visit to the 

 property about 1838. The vein apparently parallels the bedding 

 planes of the grit and ranges up to 5 feet wide. 



The Ellenville mine is another of the occurrences, similar in its 

 metal contents to the two just described but differing in the fact that 

 the vein occupies a cross-fracture in the sandstone rather than con- 

 formable with the bedding. It has been worked at different times 

 since its first opening, which is stated by Mather to have been 23 

 years before his investigation, or before 1820. It is famous for 

 specimen ores, which exhibit crystallized quartz intergrown with 

 chalcopyrite, galena and sphalerite, also often in good crystals. A 

 mill equipped with crushing and separating machinery of modern 

 type remains on the property from the last period of operations in 

 the years 1903-4. 



