Fondaway Canyon Mine (Paperweight-Half Moon; Hamburger Hill), Shady Run Mining District, Churchill County, Nevada, USAi

Regional Level Types
Fondaway Canyon Mine (Paperweight-Half Moon; Hamburger Hill)	- not defined -
Shady Run Mining District	Mining District
Churchill County	County
Nevada	State
USA	Country

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Includes the Quick-Tung mine.
Structure: NE-trending faults Low-angle thrust faults have emplaced Jurassic limestone and quartzites over the earlier host rocks. Basin and Range normal faulting has produced the north- to northeast-trending horst block that is the Stillwater Range

Alteration: Silicification

Tectonics: Basin and Range

Commodity: Ore Materials: GOLD Gangue Materials: QUARTZ, PYRITE, ARSENOPYRITE, SCHEELITE, CINNABAR, STIBNITE; sphalerite, chalcopyrite, tetrahedrite-tennantite, and pyrrhotite.

Deposit: The property hosts an intrusive-related gold-tungsten system more than 3,000 feet wide. This system contains at least 15 separate gold bearing veins, some up to 20 feet in width. Gold ore occurs in brecciated and silicified fault zones, which are nearly vertical, up to 3 meters wide, cutting marble and phyllite. Sulfide ore contains pyrite, stibnite, and arsenopyrite and is typically carbonaceous. Sulfides occur in WNW-trending marble beds in Fondaway Canyon. No skarn is present, but some scheelite is associated with quartz veinlets in the marble. The scheelite occurs as large crystals, up to 10 cm in marble. Cinnabar occurs in late fractures cutting the marble. Stibnite occurs as massive lenses in marble and with gold ore in the phyllite. The vertical extent of high-grade gold within the mineralized shear zones has been drill tested to greater than 1,000 feet (the longest drill hole extended the gold mineralization down to 1,700 feet drill indicated depth within the Paperweight-Half Moon vein system. Mineralization remains open at depth. Horizontal continuation of these zones is remarkable. The Paperweight-Hamburger Hill shear zone is the most persistent known, with a strike length of 3,700 feet and widths between 5 and 20 feet. Near-vertical, east-west, mineralized shear zones host aplite and andesite dikes, and the South Mouth, South Pit, Half Moon, Paperweight, and Hamburger Hill gold resources. The Deep-Dive gold resource is at least partially stratabound, replacing a limestone unit adjacent to the Half Moon mineralized shear zone. North-striking mineralized and post- mineral faults displace the east-west mineralized shear zones and are intruded by andesite dikes. Sparse clay and sericite occur as narrow envelopes along shear margins. Gold mineralization in the shear zones is siliceous, sulfidic, and carbonaceous. Quartz is white, milky, and multiply-brecciated. Sulfides are primarily pyrite, arsenopyrite, and stibnite with accessory sphalerite, chalcopyrite, tetrahedrite-tennantite, and pyrrhotite. Gold occurs as 5 to 20 micron grains in pyrite.

Development: The Fondaway Canyon area was first prospected in the 1870s by a group of Virginia City miners including George Fondaway. The Shady Run mining district was organized at about this time. In 1956, George Fisk discovered tungsten mineralization in Fondaway Canyon and began began producing tungsten in 1958 (see Quick-Tung deposit records). Fisk discovered gold on the property in the 1970s and began production of gold in early 1978 in a joint venture with Wilbur Robertson. Ore was removed from several open cuts on the canyon slopes and hauled to a small millsite in the canyon bottom where the ore was crushed, cyanide-vat leached and refined using a Merrill Crowe process. More than 2500 ounces of gold were reportedly produced by this operation. In 1980, Occidental Minerals Corporation leased the Fisk and Robertson holdings and did geologic mapping and geochemical sampling. A number of drill holes were completed in 1981 and 1982 and geophysical surveys were completed. Tundra gold mines was drilling the property from 1983 through 1985, working with several joint venture partners (New Beginnings, Homestake, Mill Creek) to develop the property into a producer. Several different mining concerns reviewed the economic potential of the property, leading up to Tenneco Minerals signing a lease agreement with the owners in February 1987. The mine operated from September 1989 to mid-1990 producing 13,065 ounces of gold and at least 87 ounces of silver, after which it was idle for several years. Tenneco proposed an expansion of operations to the BLM in 1990, calling for the development of the proposed Ollie, Pack Rat, and Silicon Ridge open pits, near and adjacent to the previously worked pits. Exploration activity continued, focusing on a larger, deeper, higher-grade refractory ore zone that would require underground extraction methods. In 1996, Summex Mining Company reported taking an option to acquire full ownership of the Fondaway Canyon mine. Royal Standard Minerals owned the property in 2006. Past operators drilled 568 holes, outlining the currently described resource.

Geology: The oldest rocks exposed in the mine area are fine-grained light gray to black quartzite, shale and siltstone of presumed lae Triassic age, overlain by locally slaty shale with interbeds of quartzite. The overlying Jurassic rocks are marked by the presence of several thin light gray limestone beds within the shale. The entire late Triassic to early Jurassic pelitic section hosts gold ore, although the more permeable meta-siltstones and quartzites are considered to be the primary mineralization hosts.

Ore(s): Ore formation is controlled by NE-trending fault zones and permeability of the host rocks. Near-vertical, east-west, mineralized shear zones.

Commodity List

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Mineral List

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12 valid minerals.

Rock Types Recorded

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