The Tombstone, district (31o42’04”N; 110o03’38”W) is located in southeastern Arizona to the southeast of Tucson. The district produced more than 30 million ounces of silver, 36 million pounds of lead and more than 250,000 ounces of gold with minor copper, zinc and manganese from 1879 to 1932. The ore was found as silver-lead and silver-telluride in irregular replacement deposits along fissures, breccias, and enrichments in crests of anticlines in the Naco Limestone and in altered porphyry dikes. Ore and gangue (waste) minerals that were reported from the mines included hematite, limonite, cerussite, cerargyite (horn-silver), native gold, native silver, native copper, galena, sphalerite, pyrite, alabandite, malachite, chrysocolla, psilomelane, tetrahedrite, hessite and wulfenite.
Taxi service in Tombstone (photo by the author).
Folded Paleozoic strata were intruded by a porphyry dike and mineralization was found in quartz and in vertical joints along the edge of the dike; in limestone as replacement deposits; and as bedded deposits and fissure veins.
Brecciated limestone (note the numerous angular rock fragments) underground at the Good Enough mine in the Tombstone district (photo by the author).
Many mines lie south and southwest of Tombstone and northeast of Ajax Hill in Tombstone Hills. Shafts were sunk to depths of >800 feet where they encountered a considerable influx of groundwater due to the permeable limestone.
Preparing to go underground at the Good Enough mine in Tombstone.
Work was discontinued in the mines because of the decline in silver prices and flooding: the old pumps were unable to handle the water. Based on the nature of the ore and brecciation, this area is likely to host several undiscovered deposits.