World's Fair Mine

Company

McNamec, Powers, World's Fair Development Co., World's Fair Mg. Co., Zero Mg. Co., Trench Mg. Co., Schell.

Mining District and Mines

Harshaw District

Location

?

Mineral Products

Ag, Pb, Cu-, Zn-, Au-.⁵

Type of Operation

Extensive tunnel and shaft operations. Worked from the early1880's to 1954 and produced some 13,000 tons of ore averaging about 58 oz. Ag/T, 6.6% Pb, 0.7% Cu and minor Au and Zn.⁵

Geology

Narrow fissure veins with rich argentiferous cerussite in the oxidized zone and argentiferous galena, pyrite, tetrahedrite, freibergite, sphalerite, and silver antimonites with quartz and barite in depth. The veins are along the contact between Cretaceous andesite and Laramide rhyolitic volcanics containing some limestone blocks. Wall rocks are strongly propylitized and pyritized. Some antimonial silver ore rich in gold. Strong pyrite gossan. Disseminated silver values in wall rocks. Some native silver.⁵

References

1. Mineral Appraisal of Coronado National Forest, Part 12, Santa Rita Mountains Unit, MLA11-94 (1994). SR 591-609
   http://repository.azgs.az.gov/sites/default/files/dlio/files/nid1813/usbm_mla_011-94.pdf
2. Mining in the Santa Rita and Patagonia Mountains of Arizona, U.S. Department of Interior, 1915. Republished 2014 by Kerby Jackson.
3. Mike Bertram,
4. USGS Mineral Resources Data System - using WGS84 (https://mrdata.usgs.gov/mrds/map-commodity.html#home)
5. Index of Mining Properties in Santa Cruz County by Staton B. Keith, bulletin 1991, Arizona Geological Survey, 1975