160 



or inclined fissure nearly straight, and of indefinite length and 

 depth." Such veins have usually a well-defined line or plane of 

 separation between their contents and the rock on each side, 

 which is named the loall of the vein. Now the chief peculiarity 

 in the copper ores of the region before us is, that they occur, not 

 in regular sheets of mixed metalliferous and mineral matter tra- 

 versing the rock, but in irregularly ramifying and intersecting 

 strings and bunches, in which the masses of ore are not mingled 

 with the usual foreign materials of metallic veins, but blended 

 with the adjacent red sandstone or shale, which is in a more or 

 less altered state. The nature of these accumulations of metalli- 

 ferous matter will be best understood, however, from a descrip- 

 tion of the position of the ore at two or three of the principal 

 mines. 



In the Schuyler Mine, near Belleville, in Essex, the principal 

 body of the ore is staled to be imbedded in a stratum of sand- 

 stone, twenty or thirty feet in thickness, and to dip about 12° from 

 the horizon, rather by steps than regularly. It has been worked 

 two hundred and twelve feet below the surface, and one hundred 

 and fifty feet horizontally from the shaft. The chief ores are 

 sulphuret and carbonate of copper, and they occur almost inva- 

 riably blended with portions of the indurated red sandstone. 

 Judging from the latter fact and the gentle dip of the mass, which 

 appears to be about that of the neighbouring strata, it is pretty 

 obvious that it has but little claim to the character of a true vein, 

 though it is not asserted that the quantity of ore in this mine may 

 not be considerable. It would seem as if a particular band of the 

 rock had been injected with the metalliferous matter, not filling a 

 cleft or fissure, but dispersed and as it were dissipated by subli- 

 mation through the substance of the sandstone. There is no trap 

 exposed on the surface any where in the immediate district of the 

 Schuyler Mine. 



At the Falls of the Passaic, near Paterson, traces of copper, in 

 the form chiefly of the green carbonate, occur near the foot of the 

 high cliff of trap rock, on the north side of the river, immediately 

 at the base of the Falls. A fruitless excavation was formerly 

 made at this spot, in quest of a regular vein. Huge perpendicu- 

 lar rents or chasms divide the trap, of unknown depth, and in a 



