REPORT OF THE DIRECTOR I917 39 



bodies. The ores are even, granular aggregates and very compact, 

 lacking the usual character of \~ein fillings, rather resembling the 

 country limestone in their textures. In the richer samples there is 

 little else to be seen than sphalerite and pyrite. The proportions 

 of the two minerals may vary widely in different deposits, but in 

 the usual run there is more blende than pyrite. The occurrences, 

 of which a dozen or more have so far been located, lie w r ithin the 

 main belt of limestone in the stretch from Edwards to Sylvia lake, 

 about 10 miles long. They are not alined or confined to any 

 horizon, but seem to prefer the border zone, where the limestone 

 is in contact with granitized quartz schists and gneisses and where 

 the limestone is charged with siliceous environment. An investiga- 

 tion of the deposits, of which the field work and geological studies 

 were performed by D. H. Newland, with the cooperation of Prof. 

 C. H. Smyth, jr, who has kindly undertaken the independent study 

 of the origin of the ores, was so far completed that the general features 

 of the occurrences and their economic relations could be appropri- 

 ately treated in a report, which, as already stated, has been pub- 

 lished. Professor Smyth's contribution on the mineral relations 

 and genesis "of the ores has been practically completed. 



Manganese ores. In the reports of the First Geological Survey, 

 1837-43, W. W. Mather makes mention of the presence of man- 

 ganese ore in Columbia and Dutchess counties which at that time 

 seems to have been the object of commercial mining. In his account, 

 an estimate of the deposits places the available supply at a figure 

 so large that it would be a valuable asset under the existing strin- 

 gency in the market, particularly as the information is vouchsafed 

 that the crude ores lend themselves readily to treatment for removal 

 of the earthy impurities. Prof. Nelson C. Dale undertook an 

 investigation during the past summer, which coA^ered the principal 

 localities mentioned in the early reports. Considerable difficulty 

 was encountered at first in relocating some of the old mines, but 

 after the nature of the deposits was once established the work was 

 expedited. It was found that the ores are an earthy form of man- 

 ganese (wad) and are restricted to certain upland swamps along a 

 belt that extends north and south through Canaan, Hillsdale and 

 Ancram townships. The manganese, apparently, has its source in 

 the rocks on the higher ground, from which the drainage first enters 

 the bogs where the minute quantity of the metal held in solution is 

 precipitated, after a similar manner to the formation of " bog " 

 iron ore. The deposits are restricted in area and thin, hardly justi- 

 fying their development under present-day conditions. 



