The role of geology in prospecting for lead and zinc in the Tri-state district

The present generation has seen many changes in all phases of human endeavor, and the changes which have been made in the extraction of metals from the earth are not the least or these. The application of science to our industries has revolutionized many of them. Today quantity production in our factories is an accepted thing, and in the mines, application of the same principles has made possible the working of the low-grade copper deposits of Utah, Arizona, Chile and Belgian Congo. The mining industry has made use of almost all of the sciences in one form or another to aid it in economically extracting the ore from the earth, but this paper will deal with but one of these; the science or geology and its application to the search for lead and zinc in the Tri-State District of Missouri, Kansas and Oklahoma. In the early days of mining around Joplin, Missouri, shallow shafts were sunk wherever surface indications were favorable. If ore were struck in the first shaft, drifting would immediately be started, and a \u27gouge\u27 would be in operation. If ore were not struck in the first shaft, another would be sunk some distance from the first. When the faces were worked far enough from the shaft that a long tram was necessary, the shaft would be abandoned and another sunk in the direction of the orebody. The mills in those days consisted of one or more hand-jigs, so that it was no trouble to move the mill with the shaft. Most of the early mining was done from grass-roots down to the water-level, which was usually about fifty feet from the surface. Lead ore only was taken; the zinc ore then had no value. As the price of lead ore advanced and uses for zinc were found, it became profitable to go below the water table and mine the larger ore deposits found there. This necessitated pumping the water and made the original investment too large for the individual or small group of miners. With the advent of capital, the hand-jig method of recovering the ore gave way to mechanically operated jigs and tables. The large amount of capital put into the mills required that an orebody be blocked out with a reasonable degree of accuracy, before the mill was built and money spent for pumping equipment. This state of affairs heralded the advent of the churn drill as a means of proving the existence of an orebody before a shaft was sunk. In the Joplin district three or four holes on a forty-acre tract was considered amply sufficient to prove or disprove the existence of a mineable deposit of ore. Many of the methods in use in the old Joplin district were changed with the discovery of the unusually rich deposits of ore found in the vicinity of Picher, Oklahoma. The author is especially familiar with the deposits of this camp, and it is with the geology and methods of prospecting in this camp that the present paper will deal. The methods of prospecting are now the same in all parts of the district, but the geology, especially the type of ore deposits, is different in the several camps of the district. With the coming of the churn drill, prospecting was put on a more exact basis, but it was not until the last few years that the operators have felt the need of more scientific prospecting. The application of geology to prospecting by the larger companies engaged in mining is only in its infancy, and it really has not had a chance to show what it can do, and how it can save the operator thousands of dollars by locating the barren areas and limiting the intensive prospecting to areas that have the best possibilities --Introduction, pages 1, 3