Location and Access
The Big Bear property is located in Gila County, Arizona 12 miles southwest of the town of Payson. The claims are in the Green Valley mining district on the eastern edge of the Mazatzal Mountains.
Access is via 4wd dirt road that goes east-west through the center of the property.
Elevation is averages slightly below 5000 feet. It is able to be accessed and mined year round.
All claims are located on National Forest land open to mineral entry. Part of the mineralization extends into adjacent wilderness area. Conducting mining and exploration operations on this land will have to be negotiated.
History and Geology
No record of early mining is available. The property has several shallow shafts and prospect pits. One adit has 44 feet of nearly 2% copper ore exposed.
Mineralization is concentrated in several bands with a maximum width of 40 feet. The host rock is greenstone with lesser amounts of granite and diorite. Copper oxides are prevalent in the upper portions of the mineralized area. The mineralized zones trend E-W and vary in dip.
A report by geologist Peter Marshall states:
“Generally the surface manifestation of copper mineralization on this property consists of secondary copper carbonates coating the fracture and shear surfaces of the host greenstones. In most cases these areas of secondary mineralization are associated with intrusive dikes or sills. Therefore at depth-, larger bodies of intrusive rock would show secondary mineralization,. The copper carbonates, mainly malachite and azurite occur generally as thin amorphus coatings on the fracture and shear surfaces of the host volcanics. Malachite also occurs in the intrusive dikes, in these cases crystalline malachite usually occurs near the contacts, and lining fracture voids. Thin blue crusts of the hydrous copper silicate chrysocolla also occurs in many of these mineralized cores.
Bornite also occurs in many of these surface mineral zones. This material, especially noted under an intrusive dike (marked ‘A’) ” is in the form of small grains and also rather large masses up to I/2″ thick and several inches long, filling what appears to be fracture voids. Much of the bornite, especially in the granular form is closely associated with epidote, often an epidote grain or phenocryst has a bornite center. This surface mineralization occurs over a wide area, with a general length of about 1800 feet, an average width of about 800 feet, and a vertical depth of 240 feet. A conservative estimate of the oxidation zone from surface down to 240 feet would indicate a body of approximately 32,000,000 tons of oxide copper.”
In 1956 the property was leased to Viola Mac Mining Co. which performed over 2000 feet of diamond drilling and the collection and assaying of several hundred samples. They found the average value of the vein content to be 1.98% copper. Five parallel mineralized vein structures were uncovered with widths 10 to 55 feet dipping 45 into the ridge. The area between the vein structures was found to be mostly barren at the surface but drilling found that the barren zone only extended 20 feet in depth. Below this the minimum copper content was 0.30% which consisted of zones 15 to 20 feet in thickness between enriched zones with the copper content ranging from 1.5% to 2.8% and with thicknesses of 8 to 20 feet, averaging 2.5% copper. The deepest hole was 425 feet vertical, had an average copper content of 2.5% in the mineralized zones, and bottomed in 2.5% copper.
Along with the copper content, the 405-410 foot and 415-420 foot core sections assayed approximately 0.45 oz/ton in gold. To the depth of 400 feet, 80 percent of the copper mineralization of the ore bearing formations was Malachite and Azurite with the remainder mainly Chalcopyrite.
It should be noted that Viola Mac’s drilling yielded only about 30% core recovery.
Silver was also reported to be found averaging 1 oz/ton with an “occasional” 5 foot core sample assaying up to 4 oz/ton.
Drilling indicated a mineralized area 1800 feet in length and 900 in width that “averaged 1%-2% copper with appreciable gold content.”