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beyond it, reaching upwards of seven hundred feet. The rock 

 which it chiefly traverses is the red shale, not much affected in 

 structure by the trap which overlies it in the hill, until we approach 

 very near the point of contact of the two materials. The refuse 

 matter at the mouth of the gallery of the mine itself, shows that 

 very little genuine trap was intersected in cutting this tunnel 

 across the strata. 



The copper ore, which was the object sought, was found 

 chiefly adjacent to the slightly altered shale, or immediately 

 before it becomes excessively changed in structure, near its 

 contact with the trap. This interesting circumstance of the posi- 

 tion of the ore, which embraces principally the carbonate, red 

 oxide, and silicate of copper, is by no means confined to the 

 locality before us, but seems to prevail in relation to all the 

 explorations of any magnitude hitherto made for copper within 

 the State. The theory of (ho origin of these ores, suggested by 

 this and other facts, will be presented under another head, when 

 the copper mines have been specially described. The ore, as in 

 nearly every copper locality in the State, is connected with no 

 true gangue or vein stuff, implying a genuine metalliferous lode 

 or vein, but is diffused as if by sublimation through the altered 

 red shale, filling or lining its minutest fissures, and presenting, 

 therefore, a large surface of bright green ore to the eye, while 

 the metalliferous coating is in reality extremely thin. 



Deeper in the hill, there occurs a more highly altered variety 

 of the red shale, but this is usually destitute of metalliferous matter. 

 In external aspect and structure it resembles somewhat the trap 

 rock, but its texture and composition show it to have been the 

 stratified shale changed by heat. Its fracture is conchoidal, very 

 nearly resembling that of the trap, and it has the same tendency 

 to form numerous spherical balls. 



Kew Brunswick. — The next locality which deserves description, 

 belongs to a more eastern belt of trappean injections. This 

 ridge is one and a half miles west of New Brunswick, of gentle 

 elevation, composed principally of red shale, apparently under- 

 laid in part by trap rock. The shale has an altered colour, and 

 in some of the higher parts of the hill, the trap obtrudes itself at 

 the surface in loose fragments. At one point in the immediate 



