The Fondaway Canyon Project consists of 253 contiguous, unpatented mining lode claims, covering approximately 1,806 hectares, on land administered by the U.S. Bureau of Land.
The claims are currently held by Getchell Gold under a Mining Lease/Purchase Agreement with the owner, Richard E. Fisk and by Getchell Gold Nevada Inc., a wholly
owned subsidiary of Getchell Gold.
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Summary:
The gold mineralization at Fondaway Canyon appears to conform to an orogenic intrusion-related mesothermal gold system. Although this is the most likely model for mineralization, structurally controlled, low-sulfidation epithermal mineralization cannot be entirely ruled out.
Local and Property Geology
The Fondaway Canyon area is mostly underlain by a Triassic black shale sequence consisting of thinlybedded, black, carbonaceous (phyllitic) shale and siltstone which contain a well-developed penetrative cleavage. The sequence largely strikes west-northwest and dips moderately to steeply southwest; vertical and locally overturned bedding is common. However, in areas of mineralization, mafic dikes and high-angle faults, bedding is more chaotic and commonly broadly parallel to dikes and faults.
Host rocks for the majority of the mineralization at Fondaway Canyon (Half Moon, Paperweight, Hamburger Hill and South Pit Zones) are primarily shale and mudstone of the Triassic Age Grass Valley Formation. The Grass Valley Formation has been regionally metamorphosed to phyllite and folded into east-west trending folds with approximately 180 m amplitude across the folds and vertical to slightly overturned limbs. Jurassic Age Boyer Ranch limestone and quartzite is mapped at the Colorado-Deep Dive areas and appears to be overthrust by Grass Valley phyllite.
East-west faulting crosscuts the metamorphosed sedimentary units and forms a 3.5 km long structural corridor that hosts the majority of the gold mineralization at Fondaway Canyon. Sets of north trending mineralized and post-mineral faults displace east-west trending mineralized faults. The north trending post mineral faults are probably related to basin and range development (Young, 1989). A low-angle fault, termed the “Boyer Thrust” by Page (1965) crosses the western part of Fondaway Canyon. The fault is expressed as a thick (> 10 m in some areas) zone of brecciation, shearing and strong iron-oxide development.
An Oligocene age granitic stock, called the White Cloud Canyon stock, is exposed north of Fondaway Canyon and covers an area of about 5 by 2 km. Outside of this stock, the only other exposed granitoid in the area is a Cretaceous age granite occurring about 700 m north-northwest of the Colorado zone, which is possibly underlying the tungsten skarn deposits in the central mined area.
Tertiary age west-striking dacite dykes and west-northwest striking basaltic-andesite mafic dykes, typically of 1-4 m width, occur at Fondaway Canyon and are broadly parallel to mineralized trends and structures. These dykes are altered but not strongly mineralized.
Mineralization
Gold mineralization at Fondaway Canyon occurs within sharp-walled or more diffuse shear veins within carbonaceous shale-siltstone that are characterized by strong brittle-ductile fabrics (crushing, lenticular and lens-like textures); a high sulfide content; diffuse, broken quartz—Fe-carbonate—sulfide veins and fillings; and silicification (Margolis, 2020).
The precious metal mineralization at Fondaway Canyon characteristically has a low Au:Ag ratio of less than 1:1, is interpreted to be structurally controlled mesothermal and is associated with the sulfide minerals pyrite, stibnite, arsenopyrite and lesser amounts of tetrahedrite, chalcopyrite, galena and pyrrhotite. Thin sections identify the gold to be 5 to 20 microns in size and found to occur in quartz veins and zones of silicification and sulfides with pyrite, arsenopyrite, quartz and brecciated carbonaceous siltstone (Hazen Research Petrographic Report, 1989). The carbonaceous host may account for 10 to 20% of the mineralization and is likely to exhibit preg-robbing characteristics (defined as a phenomenon in which a metal of interest is adsorbed or retained by minerals, especially due to the presence of species like. carbonaceous matter and silicates, therefore reducing its recovery potential).
The major gold mineralization occurs spatially related to faults in silicified vertical to steeply-dipping (70-85 degrees south) east-trending shear zones; but low-angle veins also occur, likely occupying Mesozoic thrust planes. Individual shears are typically 1-5 m wide but combine to form broader shear-zone stockwork corridors locally 100-150 m thick that dip more moderately than the contained individual mineralized zones. Gold mineralization is restricted to the shear zone and does not disseminate into the wallrock shale and siltstone of the Upper Grass Valley Formation unless there are stockworks of fracture quartz veins and silica replacement that permitted the migration of mineralization into the wallrock. The vertical extent of the gold mineralization is greater than 300 m based on the recent drilling by Nevada Contact and Getchell Gold. The most persistent vein zone strike length is 900 m on the Paperweight - Hamburger Hill Zone. Vein width is commonly 1.5 to 6.0 m. However, the QP observed numerous stockwork, breccia zones and silicified zones with gold mineralization that are likely spatially related to the mineralized faults with high carbon, pyrite, barite, arsenic, antimony, mercury.