Mine Tales

Mine Tales: Orphan mine yielded high-grade uranium

2014-07-07T00:00:00Z 2014-07-08T09:19:41Z Mine Tales: Orphan mine yielded high-grade uranium By William Ascarza Special to the Arizona Daily Star Arizona Daily Star

Note: This is the first in a two-part series on the Orphan Mine.

The Colorado Plateau, which extends over parts of Arizona, New Mexico, Colorado and Utah, is best known for its abundance of radioactive minerals, including uranium and vanadium ore deposits.

One isotope of uranium, uranium-235, undergoes nuclear fission, an ingredient essential to the creation of the atom bomb. Nuclear power plants create electricity using energy released by fission. Secondary uranium minerals include carnotite and tyuyamunite.

Carnotite, an important ore of uranium and vanadium, forms in sandstones affiliated with petrified trees and fossils, abundant in northern Arizona. Vanadium is highly resistant to corrosion and is a component of rust-proofing in high-speed drills.

Early uranium production in Arizona dates to 1918 with John Wade’s discovery of carnotite-bearing sandstone deposits in the Carizzo Mountains, southwest of Four Corners.

The Orphan Mine, on the South Rim of Grand Canyon National Park, later known for its high-grade uranium, was the only privately held land in the park’s boundaries until 1987.

The mine, closed in 1969, was discovered by Daniel L. “Pops” Hogan in 1893 as a copper claim and patented in 1906, eight months before the establishment of the Grand Canyon Game Reserve (later Grand Canyon National Park) by President Theodore Roosevelt.

Hogan built the Kachina Lodge for tourists at the site in 1936, figuring its profits would exceed those of his small copper mine. Due to declining tourist revenue, Hogan sold his property for $55,000 to Bertha Madeleine Jacobs in 1946.

The end of World War II instigated a nationwide interest in the procurement of uranium for atomic weapons production.

Novice prospectors explored and reported uranium localities in the Southwest, including at the Orphan.

A l951 visit by Harry C. Granger of the U.S. Geological Survey, using a Geiger counter, confirmed that Hogan’s copper deposit contained high-grade uranium, but it was considered worthless at the time.

The ore-bearing structure for the Orphan Lode is a collapsed breccia pipe “vertical pipeline column of broken rock.”

By 1953 the Golden Crown Mining Co., a subsidiary of Western Gold and Uranium Inc., acquired both the property and mineral rights. Exploratory diamond drilling began in October 1955, followed by the first shipment of 20.89 tons of ore averaging 0.53 percent U3O8 from the Orphan and trucked 92 miles to a 300-ton uranium processing mill six miles northeast of Tuba City on April 25, 1956. A sulfuric acid leaching process was used to extract the uranium.

An aerial tramway manufactured by Riblet for $61,800 was completed in May 1956 and consisted of 1,800 feet of steel rope supported by eight towers, with a 1,100-foot vertical drop. Its purpose was overcoming the challenges of topography and accessibility to the Orphan, transporting miners and supplies in two eight-cubic-foot tram buckets operated in tandem from the rim to the mine in four minutes, supplanting the former crude trail of ropes, ladders and rock steps designed by Hogan.

The tram could move 45 tons of ore to the rim a day. Bit its high expense and inefficiency necessitated its replacement in 1959 by the sinking of a hoisting shaft directly to the lode, supported by an 80-foot-high steel headframe.

One of the most iconic images involving mining the Grand Canyon is that of Orphan Mine superintendent and manager Maurice Castagne and a fellow miner riding the aerial tramway.

According to Castagne, the aerial tramway was an attraction among park visitors who wanted to ride it but were forbidden to do so by the company because of liability.

William Ascarza is an archivist, historian and author. Email him at mining@azstarnet.com

Sources: Michael A. Amundson, “Mining the Grand Canyon to Save It: The Orphan Lode Uranium Mine and National Security,” Western Historical Quarterly 32 (Autumn 2001); William L. Chenoweth, “The Orphan Lode Mine, Grand Canyon, Arizona, A Case History of a Mineralized Collapsed-Breccia Pipe” (1986); Maurice Castagne, “Grand Canyon Orphan Mine” 2004; Karen J. Wenrich and Hoyt B. Sutphin, “Recognition of Breccia Pipes in Northern Arizona,” Arizona Bureau of Geology and Mineral Technology Fieldnotes (1988).

Copyright 2014 Arizona Daily Star. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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