MINERAL RESOURCES OF THE STATE OF NEW YORK I35 



within a few feet of the surface; some are 500 to 600 feet long and 

 100 to 200 feet wide. As much as 200,000 tons of ore have been 

 mined from a single pit within 150 feet of the surface. Few, if any, 

 of the deposits were exhausted by the previous operations; the 

 production of ore became unprofitable with the loss of the local 

 markets supplied by the Poughkeepsie and other nearby furnaces 

 and through competition with the Lake Superior ores. The active 

 period of exploitation may be said to have ended about 1893. 



The ores occur in coherent masses and in earthy condition, the 

 former called " rock ore" which is sorted by hand and the latter 

 " wash ore" being the residue obtained after the removal of the 

 clay and sand by washing. The masses occur in spheroidal, stalactitic 

 and irregular shapes. The iron content of the shipping product 

 ranges from 40 to 50 per cent and the phosphorus below .5 per cent 

 and occasionally below the Bessemer limit. The sulphur content 

 is low. 



There is little doubt that in the course of time the ores will again 

 be in request. Some of the more accessible properties possibly 

 could be worked under present conditions. 



In the western part of Columbia county, a short distance from 

 the Hudson river there is a small district that has produced carbonate 

 ores. The deposits lie along the western slope of a range of hills 

 that begins just south of the city of Hudson. They are included 

 between slates and quartzites and show some points of similarity 

 to the limonites above described. The Burden mines are the largest 

 in the district, they were worked between 1875 and 1901. The ore 

 is a gray compact siderite containing some calcite, quartz and 

 pyrite. The silica percentage is apt to be rather high, and it is 

 necessary to subject the ores to a roast to remove the sulphur and 

 increase the iron. The greater part of the mined product was of 

 Bessemer character. The production of limonite in southeastern 

 New York ceased practically in 1905, since which time the industry 

 has been dormant except for an occasional shipment. 



Amenta mines. One of the larger mine workings in the limonite 

 district is at Amenia in a small north-south notch in the ridge just 

 west of the village. There are three pits, the Gridley, Palmer and 

 Weed, but all are opened on the same body of ore and together form 

 a continuous trench one-half of a mile long. The deposit lies along 

 the contact of a fissile micaceous schist which can be seen on the 

 east side of the workings at the north end, and white crystalline 

 limestone which is now concealed but is said to have been exposed 

 in the bottom of the pits and on the west wall of the Palmer pit. 



