ADIRONDACK MAGNETIC IRON ORES 89 



MINERVA MINE 



This is a small opening situated in the town of Minerva, about 

 2 miles north of the hamlet of that name. The ore body outcrops 

 on. the southern face of the long north and south ridge which rises 

 between Minerva stream and Stony Pond brook and is known 

 locally as Ore Bed mountain. The elevation is between 1900 and 

 2000 feet according to the topographic sheet. A good trail leads 

 from the highway along Falls brook to the mine. The Burden 

 Iron Co. operated the deposit and the ore was used at Troy. The 

 last work was done about 1881. 



The geological associations are very similar to those noted in 

 the mines about Crown Point. The Grenville series of limestones, 

 schists and black hornblendic gneisses outcrops in the broad valley 

 drained by Jones brook and reaches well up the confluent valley 

 of Minerva stream. It appears to form also much of the higher 

 ground, though interrupted in places by a pink gneiss of granitic 

 composition which is probably intrusive. The latter has a more 

 massive appearance than the typical Grenville gneiss and is made 

 up of green pyroxene crystals in a ground mass of microperthite, 

 microcline and quartz. This gneiss was found in proximity to 

 the ore, but not in actual contact. The immediate walls, as 

 exposed in the pits, are formed of the darker variety, carrying 

 hornblende and biotite as ferromagnesian minerals, and probably 

 belonging to the sedimentary or Grenville series. Red garnet is 

 distributed through the rock in small crystals, while pyrite occurs 

 in considerable quantity both as individual particles and irregular 

 aggregates. 



The deposit has a northwesterly strike in conformity to the 

 general trend of the country rocks. It has a flat dip of not more 

 than io° northeast, but as the surface rises sharply in that direc- 

 tion, the overburden soon becomes too heavy for open-cut work. 

 There are a number of pits and trenches along the outcrop, 

 extending altogether for a distance of 100 rods. A breast of ore 

 12 or 15 feet thick is exposed in the middle section. The thick- 

 ness diminishes toward the ends, but it was not possible to estimate 

 the size with accuracy owing to the partial filling in of the pits. 

 Some drilling is said to have been done a number of years ago to 

 test the ore body in depth; the records, however, have not been 

 available for use in this report. 



The ore is a fairly coarse, granular magnetite. Samples ta*.£ii 

 from different parts of the body indicate an iron content above 



