Mohave County miner., 1896-05-02

| "ouakef hcutubcn says me mfnerAllzed zone IS stratum ot altered limestone, ranging from to S5 feet in thickness thoroughly impregnsted with arsenic in the form of realgsr and mercury or qnick silver in the form of cinnabar, carrying gold in varying quantities, ranging from a trace to several hundreds of dollars . ton. The apex, or vein, Is generally rather ainty limestone, which Is some. times decomp posed clnyey material of yel low-ocher color, which usually assays from trace to 3t ton. Ia some place. in the ore.bearing zone s,licia has heen deposited as replacement pseudo nor. phic. The hanging wall Is black clay sbale. the color being due to the carbon contained. This sbale usually carries .hs coal fossils and sometimes carries finely disseminated iron pyriies, which is not, however, srsenical. The shale is very issile in character and contains enough lime SO that when exposed 10 the atmosphere it quickly shades away to {. clay. The foot wall of the gone is usu ally hard crystalline limestone, but 1t is not at all uniform. Holes and channels are formed where mineral solutions have replaced the lime, and in these channels lhe ore is generally of better quality than Is the general average of the whole mass. In many places the workable sooe has developed a thickness of twenty four or thirty feet, and the average thickness of the ore bodies may be placed at fifteen to eighteen feet. The direction of the foot wall channels may be stated as ap proximstely parallel with the local dip of the strata The appearance of the ore IS yellow, brown, red brown, sometimes gray or black, and the limestone itself, when it is colored, usually carries good working values. The payable portion of the ore of the vein on the foot. wall eide can only be determined by assay, while the hanging wall side is distinctly marked.
 The veln in the Mercur district is not vein at all as the term is usually under. stood. A better name would be an in. ter-calste vein or mineralized zone of country rock. The Germans, recognizing this character of deposit, have given il the name of "fahlband," meaning s rotten stratum. It is undoubtedly true that the silica occurs as chemical re placement, and the only difference b :. tween the Mercur district and other To caliiies farther south is that in the Mer. as yet incomplete At the Mercur dis trict the payable values do not always follow one stratum. There is evidence that there are at least three separate and distinct minerslzed zones. It is also probably true that the whole area of the country will no. be underlaid with goidbearing rock in payable values, but that the shoots will assume definite boundaries with trend lying between the walls in definite and direct course As to what this direction is at the pres ent time has not been determined There has been some discussion among mining men as to the probability of the ore bearing zone at Mercur carrying with 1t extra lateral rights. From the general construction of the zone, and the fact that there is hardly an instance in the Mercur district where the letter of the miuing law has been strictly complied with, it will be very difficult to enforce mining rights on the dip of the vein out. side of the vertical boundaries projected.