97 



of ore. Only the top stratum, over a small area, has been 

 worked. The greatest depth to which they have yet pene- 

 trated is 42 feet, and generally much less. The upper por- 

 tion of this ore body, has the ore inclosed, or mixed with 

 pulverent red ochery clay. Twenty-five solid feet of this 

 mass yields one ton of ore .on an average. This is about 

 one-tenth in bulk of ore, but much more- in weight. This 

 light ocherous material is easily washed away, and the ore 

 left clean. 



Below this top stratum, of as yet unknown thickness, is 

 another stratum, carrying apparently richer ore, but imbed- 

 ded in tough, or unctious, red clay hard to wash the min- 

 ing, or cleaning of which, has not as yet been attempted. 



The foregoing notes embrace all the facts brought to light 

 by three years mining on this deposit of ore. . 



A careful examination of all the exposed, adjacent and 

 underlying rocks here, strongly impress the opinion, that 

 this great body of iron ore occupies the site of a great basin, 

 that existed here at the close of the Cambrian Period ; and 

 was filled in at the beginning of the Silurian Epoch. The 

 extent, or form of this great basin, holding the deposit 

 under consideration, can not yet be determined, or approx- 

 imated. We can not learn from the exposures made, 

 whether the axis of the basin conformed in any respect, to 

 the axis of the uplift. Or whether the great fault which 

 sheared through it, with much displacement, cut it in the 

 middle, or on the eastern or the western side. Only of one 

 thing can we be certain, that the axis of uplift, and the 

 great fault heretofore described, cut this deposit from N. E. 

 to S. W. for about a, mile and a half; and for that distance 

 exposed it on its N. W. side. While on the S. E. side, the 

 corresponding portions of the deposit, are sunk from 1,500 

 to 2,000 feet beneath the surface. It is also probable that 

 this deposit does not extend westward much, if any, farther 

 than the west line of section 5. Though the great mass of 

 irony clay, in which the ore is contained, extends a consid- 

 erable distance beyond this line, but little ore has yet been 



