304 NEW YORK STATE MUSEUM 



If the ore-bearing solutions were surface waters, the Helderberg 

 and Onondaga limestones may well have been the gathering ground 

 and the sources of the metals. In this event the concentration 

 would have been effected by descending waters. The other view 

 of the matter, that the waters came from below, would involve 

 deep-seated circulations and some stimulus in the form of igneous 

 activity, of which there are some indications, as already stated, in 

 the secondary minerals that occur in the sandstones. The evidence 

 in support of either explanation, however, does not suffice at present 

 to form an intelligent opinion in the matter. 



The great bodies of zinc ores at Franklin Furnace and Ogdensburg, 

 New Jersey, are some 25 to 30 miles south of the Shawangimk 

 district. They have the Precambrian limestones for wall rocks and 

 have little in common in their mineral features with the present 

 occurrences. 



Mining developments. The principal operations in the district of 

 recent date have been carried on at the locality near Summitville, 

 Sullivan county, where mining has been revived in the last year or 

 so by the St Nicholas Zinc Co. The deposit was worked rather 

 extensively between 1830 and 1840, as appears from the description 

 by Mather who refers to the operations at greater length than in 

 reference to the other mines. At that time it was known as the 

 Shawangunk deposit and the lead ore was treated in a local smelter 

 at the foot of the mountain. It consists of a fracture zone, parallel 

 or nearly so to the bedding of the grit, along which has been deposited 

 secondary quartz and sulphides of zinc, lead, copper and iron. The 

 vein appears to conform to the dip of the strata which follows the 

 slope of the mountain but at a higher angle (about 35°). The vein 

 ranges from a few inches to 3 to 4 feet thick. In places it gives an 

 almost solid breast of ore, but ordinarily there is a good deal of rock 

 intermixed. 



The present work thus far has been limited practically to the 

 extension laterally of the old openings. These consist of an adit 

 level 220 feet below the outcrop, measured on the vein, and a series 

 of minor levels at intervals to the surface. The main drift measures 

 400 feet on the course which here is about north-northeast. Enough 

 ore was encountered in the old slopes to sustain operations for the 

 first few months and it was believed by the engineers in charge, 

 that the profits therefrom would repay the costs of the new equip- 

 ment. The continuation of the ore in depth is the critical circum- 

 stance on which the future of the enterprise will depend and there 

 is little in tJie present conditions on which tQ base, an. opinioa ia 

 regard to the probabilities of the future ore supply >. 



