Tom Reed Mine/Western AZ - OODH
The San Francisco district in western Arizona encloses numerous mines within the Oatman and Katherine camps, 30 miles southwest of Kingman. This district produced more than 2 million ounces of gold from quartz veins in fault zones hosted by granite, rhyolite, latite and andesite. The veins are simple with many stringers and typically contain andularia, quartz and calcite. In many cases, veins show banding.
Most of the important veins were found on the western slope of the Black Mountains. Gold was discovered in this region in 1863 at the Moss vein between Oatman and the Katherine mines. In 1901, rich gold ore was found in shallow prospects dug on the Tom Reed vein in the southern part of the district. This was followed by a rush in 1902 resulting in discovery of the Gold Road vein. Mines in the district included the Hardy, Moss, Aztec, Oatman, Katherine, Tom Reed, Pioneer, Gold Dust, Gold Ore, Telluride, Ben Harrison, Black Eagle, Murdock, Leland, Sunnyside, Pyramid, Arabian, Treasure Vault, Gold Chain, Big Four, Red Lion, Big Jim, Frisco, Tyro, Time and others.
The Tom Reed vein is hosted by Oatman Andesite. This vein strikes northwesterly and has a northeasterly dip. The vein was controlled by faulting and is offset at the Mallory fault near the Big Jim Mine. The ore body is lenticular and mildly pyritized, and has some bleaching with secondary kaolinite, calcite, and chlorite. South of the Tom Reed mine, most faults and veins trend E-W. A 20-stamp mill was erected on site in 1904. The main ore shoot of the United Eastern and Tom Reed Extension claims had a shoot reported to be 750 feet deep, 950 feet long and 48 feet thick. This vein reportedly averaged >1 opt Au and produced 500,000 tons of ore: the ore grades declined with depth.
The Moss vein was faulted at several locations and also exhibited an E-W trend. The vein was traced over a strike length of > a mile. The Katherine mine was developed on a vein in sheared granite near the Colorado River. This vein had a width of >60 feet at the surface and pinched at depth. It was traced for >1,700 feet along strike. The mine was developed to at depth of 900 feet.
Many mineralized faults in the district are poorly exposed and some are hidden under gravel. The veins are simple, being tabular bodies of quartz and calcite with well-defined walls, while others consist of several vein stringers separated by barren rock. These consist of quartz, calcite, andularia, fluorite, gold and silver.
Ore shoots in the district show an apparent decrease in grade with depth sometimes running half to a third of ore grades in the upper portions of the veins. For example, the Tom Reed extension was reported to average ~1 opt Au. Below the 800 foot level, the gold content declined to ~0.5 opt Au. At the Big Jim vein, ore grades were just under 1 opt Au to a depth of 600 feet. Below this depth, ore grades declined to ~0.3 opt Au.
Only minor placer activity was reported in the district, primarily along Silver Creek, because of lack of water and small gold grains in the lodes (Lausen, 1931). This district offers considerable potential for new lode discoveries as well as exploration at depth. Many old mine reports suggested that the more prominent mines ceased production because of declining gold values at depth (at gold prices of about $20/oz). At today’s price, some of these are likely minable to greater depth.
The Gold Road mine in the disrict, has been active on and off for nearly a century. Recently, the mine reopened and began production.
Conclusions
Eastern Arizona has several important mines and known mineral deposits with potential for discovery of additional gold and copper resources in essentially every district. Areas of notable interest for gold are the Gleeson, Oro Blanco and Copper Creek districts. Western Arizona has many more primary gold deposits than eastern Arizona and there are a number of lode, placer and dry placer deposits that suggest several deposits likely remain hidden and undiscovered. Some notable deposits in western Arizona include the Vulture mine and Rich Hill within the Wickenburg district, the Katherine and Oatman properties in the San Francisco district, prospects in the Wallapai district, gold in Lost Basin district, and gold in the La Paz district within the Dome Rock Mountains, Plomosa Mountains and La Posa plain between these two mountain ranges. These will be discussed in a follow-up article on Arizona.
So how much is the mineral wealth in Arizona? The Arizona Department of Mines and Mineral Resources reported $7.6 billion in minerals were mined in 2007 – much of this wealth was from copper and precious metals. So what does government obtain from this? The answer is taxes and the state of Arizona gets jobs? It is very likely that more jobs and a greater tax base could be created by stabilizing the border with Mexico, creating incentives for exploration companies and gold prospectors to explore, and most of all, significantly cut taxes and government bureaucracy. All too often in natural resources, permitting is duplicated at the county, state and federal levels.
For instance, while drilling for diamonds in Colorado a couple of years ago, a company I was consulting for was required to obtain the same permit (with different requirements) from three different government agencies.
