OF ARKANSAS. 57 



More or less lead ore has been found at different points, over about two- 

 thirds of township 20 north, range 19 west of the 5th principal meridian* 

 according to the representations of Judge Brickcy, who had been formerly 

 extensively engaged in the lead business in Missouri, and has been recently 

 employed by Coka &Mitchell, the owners of these mineral lands, to en- 

 deavor to follow the course of the veins on their property. 



The ore discovered has been sometimes float or gravel ore, scattered on 

 the surface or partially imbedded through the bare surface rock, in "strings," 

 "sheets," thin veins, and occasional " pockets;" also in the interstices, cre- 

 vices, and even horizontally between the layers of the bedded rock. 



The lead-bearing Magnesian limestone, which commences, usually, 

 about 80 to 100 feet beneath the summits of the ridges, has, in general, a 

 capping of hard, white, quartzose sandstone, 4 to 1G inches in thickness, 

 with intervening beds of ferruginous and argillaceous shales of, usually, 

 only a few inches or a foot or two in thickness. 



The section of the upper 90 to 100 feet of the ridges, in this lead region, 

 may be represented approximately by the following section: 



Chert 50 feet 



Thin-bedded magnesian limestone 15 " 



Encrinital limestone and marble rock 25 to 30 " 



Sandstone, mostly hard, white and quartzose. bedded G 

 to 9 or sometimes 16 inches: average say, the " cap 



rock'' of the lead miner of Carroll county 1 " 



Ferruginous and argillaceous shales 1 to 2 " 



Lead-bearing magnesian limestone with some alterna- 

 tions of siliceous rocks extending for 200 to 250 feet 

 down to the beds of the streams and general drainage 

 of the country > • • 250 " 



These latter rocks are, lithologically, much of the same character as the 

 strata represented in the 250 feet of the lower part of the section, on Su- 

 gar-loaf creek, in Marion county. 



It appears that the surface of the magnesian limestone, under the sand- 

 stone, has suffered from irregular denudation, previous to the deposition 

 of the sand, which went to form the succeeding stratum, which is, in con- 

 sequence, sometimes quite irregular in its thickness, even in short distances, 

 where the sand has been swept into the eroded cavities; such an action 

 has taken place close to where the 40 feet shaft has been sunk in this 

 county. There, a great mass of isolated sandstone, which has resisted the 

 action of decomposing agencies, beyond that of the adjacent members, 

 stands out as a bold mass, as if it might have been a wall or dike, form- 



