128 NEW YORK STATE MUSEUM 



a few degrees toward the north. So far as can be estimated from 

 the surface the breast of ore must have averaged about 15 feet. 

 The walls in both pits consist of microperthitic gneiss of granitic 

 character with the high percentage of magnetite nearly always 

 present in this rock. No analyses of the ore have been obtainable; 

 the general average is probably about that given for the Bowen 

 & Signor deposit. 



Tremblay mine. This deposit is situated in the town of Saranac 

 2 miles west of Clayburg. The workings which consist of one or 

 more pits are now filled with water so that neither the deposit nor 

 the walls can be seen. Putnam has recorded that in 1880 the 

 main pit was from 150 to 200 feet long and 75 feet deep. Little 

 work was done after that date. The analyses of ore (1) and con- 

 centrates (2) are quoted from his report. 



1 2 



Iron 28.62 65.01 



Phosphorus .017 . 004 



ST LAWRENCE COUNTY MINES 

 On the west side of the Adirondacks, St Lawrence county con- 

 tains the only deposits of nontitaniferous magnetites that have 

 been extensively mined. The principal workings are' at Jayville, 

 Benson Mines, Fine and Clifton in the southeastern part, near the 

 headwaters of the Grasse and Oswegatchie rivers. They are 

 reached most readily by the Carthage & Adirondack Railroad, 

 which affords direct communication with Lake Ontario at Sacketts 

 Harbor and crosses the main railway lines at Watertown and 

 Carthage. The accompanying sketch map [fig. 21] gives the loca- 

 tion of the larger deposits. 



The deposits were discovered many years ago. Some of them 

 are mentioned by Emmons who did not, however, consider them 

 as available resources at the time owing to their remote situation. 

 On that account they received little attention from the early iron 

 manufacturers of St Lawrence county. Most of the ore used in the 

 old furnaces came from the hematite deposits around Gouverneur 

 and Antwerp. The region about the mines is largely wilderness 

 with few beaten routes of travel. 



General geology 



The Adirondacks fall by gradual stages toward the St Lawrence 

 plain. The surface in this section has a mean elevation of from 



