The Griffon Project is located in White Pine County, Nevada, approximately 85 road kilometers southwest of the community of Ely. The claim block consists of 89 unpatented lode claims on federal lands administered by the U.S. Forest Service. The Property hosts the historic Griffon mine, which produced approximately 100,000 oxide ounces of gold. Griffon is situated at the southeast end of the Cortez trend, and is one of a series of deposits, including Pan and Goldrock, hosted in Mississippian siliciclastic and carbonate strata.
Recent exploration work includes data compilation and digitization, geological mapping, soil sampling, rock sampling, ground gravity surveys, claim staking, and 3D modeling. This thorough analysis has identified a number of new drill targets, and Logan considers Griffon to be highly prospective for discovery of additional, sedimentary rock-hosted (Carlin-type) gold mineralization. The Project is permitted.
Location and Land Tenure
The Griffon Property is located in the central White Pine Range, at approximately 39o 03’40” North Latitude, 115o 24’ East Longitude, at elevations of 2,220 to 2,600 meters. The claims are accessible from the community of Ely by traveling 45 kilometers southwest on Highway 6, then another 40 kilometers northwest on a series of gravel roads to the project area. The Forest Service portion of this access route is not maintained in the winter, and, due to the high elevations, may not be open from December-April.
The Griffon claim block consists of 89 unpatented lode claims located on Federal land administered by the U.S. Forest Service.
Geology and Alteration
Paleozoic carbonate stratigraphy underlies the project area and a majority of the White Pine Range. These rocks display evidence for multiple deformation events, including folding, thrust faulting, and both low-angle and high-angle normal faulting. The superimposed effects of this protracted structural history create a complex, three dimensional mosaic of structural blocks within the project area.
Tertiary volcanic rocks crop out throughout the eastern and southern portion of the Griffon claim block, although no volcanic rocks occur immediately adjacent to the known gold deposits.
The principal alteration types associated with gold mineralization are decalcification and argillization. Although some strongly silicified rocks contain ore grade gold, such as the jasperoid ribs which occurred above the Discovery Ridge deposit, more commonly strongly silicified rocks are not gold-bearing. These alteration facies, together with secondary iron oxides, are invariably present where gold is detectable and are conspicuous where higher grade gold occurs.
Mineralization exhibits clear structural and stratigraphic controls, but is focused for the most part in a calcareous shale unit, transitional between the Joana Limestone and Chainman Shale. The Pilot Shale, which is host to mineralization in other nearby deposits, does not appear to be mineralized in the vicinity of the pits, but may be elsewhere. Most of the drill holes were very shallow and did not test this unit to any significant extent.
Post-mineral oxidation of original sulfides is complete in all holes logged to date. As is common in disseminated, sediment-hosted gold deposits, Griffon ore contains elevated levels of arsenic (100-208 ppm), antimony (6-10 ppm), and mercury (410-1040 ppb) Anomalous zinc also occurs in Griffon ore, whereas concentrations of silver, copper, and lead are negligible.
The Griffon gold deposit lies outside of any historic mining district and consequently there is little or no evidence for exploration activity until relatively recent time. The area was explored by Shell Oil, Placer Dome, and Billiton; the latter identified the Discovery Ridge deposit in the late 1980’s. Several changes in ownership ensued before the project was ultimately acquired by Alta Gold.
Drilling by Alta from 1990-1995 resulted in the discovery of the Hammer Ridge deposit and a decision to mine. Between 1997 and 1999, Alta mined approximately 100,000 ounces gold at a grade of 1.3 g/t of gold from the two deposits. A proposed expansion of the Hammer Ridge pit was not completed before the mine ceased operation in 1999, leaving a small, unmined resource adjacent to the southwest wall of the pit.
The next phases of work at Griffon could include detailed geologic mapping and character sampling within the pits, preparatory to an RC drilling campaign. The search for additional mineralization on the property has, appropriately, focused on areas of structural complexity related to north-northwest and east-southeast-striking faults, and where the Joana-Chainman transitional unit is exposed on surface or is believed to lie at shallow depth below cover rocks. Multiple drill targets have been defined to the north and south of the historic mine, on the basis of rock-chip and soil gold anomalies, as well as results of historic drilling. Most drill holes will have multiple targets, testing deeper potential for mineralization in the Pilot Shale as well as the Chainman / Joanna contact.
A total of 26 drill sites are permitted and bonded.
Dr. Craig Bow, Vice President Exploration of Logan, is a Qualified Person (“QP”) as defined by National Instrument 43-101. The QP is a member in good standing of the American Institute of Professional Geologists as a Certified Professional Geologist (CPG.). Dr. Bow has reviewed and is responsible for the technical information disclosed on the website relating to the USA Gold Projects.