Or ARKANSAS. OJJ 



The foil wing section will show the succession of the rocks at "Cala- 

 mine," and the relative position of the zinc ore: 



Slope to the top of the hill covered with chert and scattered 

 masses of brown oxide of iron, resting on limestone with cherty 



segregations 35 f ce t. 



Zinc ore, resting on cherty magnesian limestone (b) of the previ- 

 ous section 35 « 



Calciferous sandstone 10 " 



Magnesian limestone- , . . \q « 



Spring at " Calamine" furnace " 



86 " 



The ore bed in the above section is only a few yards from the smeltin 0- 

 furnace, and is called the " Koch mine," after Dr. Koch, one of the mem- 

 bers of the smelting company. 



The most extensive deposits of calamine seen, were at the c: Hoppe 

 mine," section 19, township 10 north, range 2 west; " Bath mine," section 

 29, township 17 north, range 3 west; and the " Raney mine," three miles 

 south-east of Smithville. 



At all of these localities of calamine, the ore occurs under precisely the 

 same conditions; consequently a description of one, will answer for all. 



The " Hoppe mine " is opened on the north-west side of a low and very 

 gradually sloping hill, some fifty feet above the valley. A great manv 

 tons of calamine have already been taken out from the present opening, 

 which is about six feet deep; and the ore has been proved to continue to 

 a depth exceeding fifteen feet, by trial shafts, sunk for this purpose. The 

 greater portion of the ore, lies in irregularly curved and hollow masses, 

 sometimes covered with rusty-looking crystals of carbonate of zinc, having 

 its interstices, as well as the intervening spaces between the blocks, filled 

 with a tenacious, red, ferruginous clay. This clay is found resting upon 

 a magnesian limestone, about four feet thick, presenting the appearance 

 of a segregated mass, and is traversed by small veins of the carbonate 

 and sulphuret of zinc; the former, sometimes, in beautiful rose-colored 

 crystals. The calamine resting on, or in close proximity to, the dolomitic 

 bed rock, usually presents a brecciated appearance, caused by the 

 mammillary opalescent carbonate of zinc, enclosing fragments of an amor- 

 phous zinc ore, which has the appearance of dolomite, and which had 

 very probably that composition, but has become carbonate of zinc by a 

 process of displacement. 



Some specimens of the ore found at these mines, convey the idea of a 

 simultaneous deposition of the zinc and dolomite; while others rather 



