OF ARKANSAS. O11 
The follwing 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: ++++++sse. SiGe aS wa a ee 66 wad aR wviaavasa BF feet: 
Zine ore, resting on cherty magnesian limestone (0) of the previ- 
OUS SECTION: «sere reer eer eveee esis WAL NS LBs eae ames BH 
Calciferous sandstone: ose reece eerste ac eneee eee eae secre veee JD & 
Magnesian limestones +s 40st cdiwaw een weer ened eweeg aa TE 
Spring at “ Calamine” furnace eee eee pe eee eens sees we even Qo « 
86 ce 
The ore bed in the above section is only a few yards from the smelting 
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 “ Hoppe 
mine,” section 19, township 16 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 many 
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 
yery 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 
