ADIRONDACK MAGNETIC IRON ORES 



37 



MINES NEAR FORT ANN 



The Potter, Podunk and Mt Hope mines are situated on the west 

 side of Putnam mountain in Fort Ann township, Washington co. 

 They are reached most conveniently from Fort Ann village which 

 by the indirect wagon road is 9 miles southeast. The elevation of 

 their outcrop according to the topographic map is about 900 feet. 

 The total production of the three mines is reported to have been 

 about 350,000 tons. 



Potter and Podunk mines. The ore bodies outcrop near the foot 

 of Podunk pond and but slightly above its level. They are included 

 in a belt of schists which belong probably to the Grenville series, 

 though no limestone was found in the vicinity. The schists, as 

 exposed in the hanging wall at both shafts, consist of quart zose 

 bands alternating with thinly laminated hornblendic and micaceous 

 layers. They carry considerable amounts of pyrite. Their dip is 

 45 northeast. The rock on the foot-wall side is concealed for some 



Cross-section of the Potter mine, showing wall rock (Grenville schist) cut 

 off on the south by granite 



distance, but at one point midway between the two mines and 100 

 feet south there is an exposure of reddish gneissoid granite. This 

 rock is found to the west in frequent outcrops and in such relation 

 with the schists that its intrusive character is plainly indicated. 

 It is a microcline, quartz, hornblende granite quite like the Ham- 

 mondville type except that the texture is usually more finely 

 granulated. 



The Potter mine is 250 feet northwest of the Podunk. It was 

 opened in 1879. A slope 100 feet long runs down the footwall 

 at an average inclination of 32 . At the time of Putnam's report 

 the ore had been stoped out for a distance of 175 feet southeast of 

 the slope. His report contains a sketch of the workings from which 



