Abril Mine (Dos Hermanos Mine; Herrera Mine), Cochise Stronghold, Middle Pass Mining District, Cochise County, Arizona, USAi

Regional Level Types
Abril Mine (Dos Hermanos Mine; Herrera Mine)	Mine
Cochise Stronghold	Canyon
Middle Pass Mining District	Mining District
Cochise County	County
Arizona	State
USA	Country

A former small underground Zn-Cu-Pb-Mo-Ag-Au-Wollastonite-Asbestos-Bi-Be-Li-Cd-Ga-Co-W mine located in the South-central sec. 34, T.17S., R.23E., 5 km almost due north of Mt Glenn in the Dragoon Mts., 2 air miles north of the San Juan Mine or 21 miles from Tombstone, on the western slope of the Dragoon Mountains, at an altitude of approximately 6,600 feet. 10 unpatented claims in 1952. Discovered and first produced 1903. Closed 1953. Owned at times, or in part, by the Abril Brothers and H.W. Smith of Tombstone (1943); Bargin Mines, Inc. (part of 1945) and the Shattuck Denn Mining Co. (Dec 1945- ).

Mineralization is base metal sulfides and rare minerals in irregular pyrometasomatic deposits skarn minerals (lime silicates) in a tactite zone in Pennsylvanian-Permian Naco Group limestone cut by granitic intrusive and rhyolite porphyry dikes. Orebodies are irregular replacements in impure beds within the lower 70 feet of the limestone. They are localized beneath the zone of bedding-plane faults, and occur associated with northeast fissures. Host rock unit is the Naco Group Limestone. An associated rock unit is the Stronghold Granite.
The top of the ridge east of Abril Camp consists of fine-grained, light-colored quartzite approximately 80 feet thick. It is overlain, on the eastern backslope, by a thick series of metamorphosed, locally foliated shale and arkosic sandstone.

Underlying the quartzite is limestone, approximately 570 feet thick. Its upper portion consists of massive, locally cherty beds which are largely metamorphosed to marble. Its lower portion, 70 feet thick, is made up of impure, shaly limestone, locally converted to contact-silicate minerals (tactite).

Underlying the limestone is arkosic quartzite with a maximum observed thickness of 100 feet. It is underlain, with intrusive contact, by granite. Fine-grained, light-colored arkosic quartzite, commonly 25 to 100 feet thick, underlies the limestone and rests upon the instrusive Stronghold granite. The two quartzite members and the limestone between them are regarded as Permian.

The sedimentary beds at this mine dip northeastward at angles of 25º to 50º. Exploration has shown that the Stronghold granite intrudes the lower quartzite subparallel to its bedding. A northeastward-trending dike of the granite 175 to 300 feet wide cuts the sedimentary beds immediately north of adit 5. Near this dike the beds have been complexly faulted and sharply folded. A fault sipping 50º to 60º northeastward strikes N.30º to 45º W., through the portal of adit 3, bringing quartzite on the SW against limestone on the NE.

Workings include 5 adits, tunnels on 5 levels, numerous stopes and winzes. Tunnels open at elevations ranging from 5320 feet to 6441 feet.
Nearly 30,000 tons of zinc-copper ore were produced intermittently since 1914 but mainly during 1945-1952. 1947 production was some 9,900 tons of ore milles that yielded, in addition to the zinc, 188,162 pounds of Cu, 12,725 pounds of lead, 3,508 oz. Ag and 26 oz. Au.

A government exploration loan for drifting, raising and drilling was granted in the early 1950's.

Other Databases

Link to USGS MRDS:	10026967

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References