Wisconsin and Missouri Lead Region. 69 ' 



the expense of cutting and burning. Oak, elm, buttonwood, hick- 

 ory, maple, cedar, cherry, &c. are plenty. The oak is princi- 

 pally white oak and post oak ; locust and mulberry trees grow 

 wild, and the latter bear good fruit. 



As to the nature of the ore, its origin, by a right idea of which 

 some judgment may be formed of its probable continuance, it 

 seems that the crevices or fissures which- the workmen describe 

 as occurring in their diggings have served as passage ways 

 through which the ore has been projected from below, either in 

 a melted state or in a state of sublimation, or by more slowly 

 acting electrical causes ; and that near the surface on the line of 

 fissures, (which is likely to be nearly the line of contact of the 

 two rocks,) the ore has found favorable circumstances to spread 

 and deposit itself; and further, that these same circumstances 

 may be expected to be renewed at different depths, and the ore 

 there found in lateral injections between the limestone strata, 

 in veins and in the main fissures themselves. Veins of calc 

 spar are of frequent occurrence in these rocks, and one in partic- 

 ular was discovered some years since iu the red rock not far from 

 the present copper diggings, of uncommon thickness. These 

 also accompany the better developed copper ore veins in the pri- 

 mary rocks on Lake Superior and in other parts of the world ; 

 and Dr. Houghton has remarked of them, that they pass into 

 veins of copper ore, and veins of copper ore may be traced through 

 different changes till they become veins of calc spar. 



Copper ore as well as lead ore is obtained to some extent in this 

 formation in England. The deepest mine in that country is the 

 Eaton copper mine in Staffordshire, the shaft being four hundred 

 and seventy two yards deep in the mountain limestone. 



One of the other localities to which I have referred, as contain- 

 ing indications of veins of copper ore, is on the other side of 

 Jack's Fork, connected with this same red rock ridge, not two 

 miles from the old diggings. The limestone and the red rock 

 are both well exposed, excepting just at the point of contact ; 

 they both manifest the same variety of changes as they approach 

 each other that they do at the old diggings — the same porphy- 

 ritic appearance of the quartz rock, the same breccia that there 

 filled the rotten vein is here noticed, and small pieces of carbo- 

 nate of copper have been dug up from a hole only four feet deep. 

 But there seems no probability of here finding a large deposit of 

 surface ore. 



