Drilling Commences With Improved Understanding From Geophysical Interpretation At The Gold Chain Project
OTTAWA - Gold79 Mines Ltd. reported the completion and analysis of an airborne magnetic and radiometric survey over its Gold Chain project located in Mohave Co., NW Arizona. The Company has commenced the planned 1,100m drill program at Gold Chain.
Derek Macpherson, President and CEO, said, "The results of this geophysical survey, coupled with ongoing mapping and sampling work, leads us to believe we have the potential to uncover a larger gold system at Gold Chain. We are excited to be embarking on this Phase 2 drill program that includes Gold79's first drilling at the Sheep Trail patents. Recent work at Sheep Trail has returned more than 15 samples with plus 10 g/t gold while this area has never been systematically explored."
In low-sulphidation epithermal systems, such as the one at Gold Chain and within the Oatman District, areas of magnetic destruction ('quiet' zones or magnetic lows) and potassium enrichment may reflect the location and aerial extent of hydrothermal alteration and associated gold mineralization. The high-resolution aeromagnetic and radiometric data have been used to identify three magnetic quiet zones: two of these clearly correspond, over about 7 kilometers of strike, with gold-bearing zones associated with Miocene felsic dikes and structures. The distribution of gold values from surface samples, along with the survey results.
A third magnetic low closely coincides with the Frisco Graben which is an emerging target defined by a structurally controlled flow dome complex formed along the margin of a NW-trending, elongate graben. Its proximity to the Tyro vein system and intense argillic alteration provides vectors for shallow (<100m) targets.
The most significant potassium anomaly identified in the radiometric survey closely coincides with the extensive gold mineralization identified in the 'Golden Elbow' composed of the Banner, Sheep Trail and Boulevard mines. Previous drilling returned 3.1m at 10.68 g/t gold from Banner and the Sheep Trail and Boulevard mines are being drill tested by the Company for the first time in the current drill campaign.
Based on the results of the geophysical and radiometric survey's Gold79, has added 18 claims on the southwest portion of the Gold Chain project.
Robert Johansing, Vice President, Exploration, said, "Our interpretation of the airborne magnetic and radiometric survey, along with the mapping and sampling Gold79 has completed over the last two years, suggests a potentially large-scale, low-sulphidation epithermal gold system hosted by several geologic settings. wThe Phase 2 program is designed to test the near surface portion of this much broader target. The close coincidence between gold mineralization, hydrothermal alteration, potassium enrichment of the felsic rocks and the magnetic 'quiet' zone support this as a deserving target for our current exploration drilling."
Gold79 also has commenced Reverse Circulation (RC) drilling at the Tyro, Sheep Trail and Boulevard mines. A total of 1,100 meters is anticipated with hole depths of less than 150 meters.
The Sheep Trail claim block was purchased by Gold79 in January of 2022 and has now been mapped and partially sampled revealing a structural corridor over the length of the claim block (~1.5km) hosting veins and stockwork zones with elevated gold values including 7.0m of 5.06 g/t gold and 3.7m of 19.52 g/t gold from surface outcrops.
Drilling across the Tyro vein system will focus on a broad zone (up to 60m) of quartz veinlets and hydrothermal breccia at the south end of the vein system. Previous work, including drilling in 2021 across the north end, returned 21.3 meters at 2.0 g/t Au and sampling of the Tyro mine 200L revealed 25.4 meters at 2.53 g/t Au. Current drilling at Tyro is designed to provide Gold79 insight into the continuity of gold values along this greater than 1km vein corridor.
All holes are designed to offset surface gold mineralization between 0 to 100 meters below the surface.
The high-resolution aeromagnetic and radiometric data have been used to map regional/district-wide structure and identify the structural controls of hydrothermal alteration and mineralization. This survey has delineated zones of magnetic destruction that reflect the location and aerial extent of hydrothermal alteration and thus fossil geothermal systems.
The Gold Chain project lies within a classic adularia-sericite epithermal gold province best characterized by the historical Oatman district several kilometers to the south. These gold deposits consist predominantly of quartz-adularia-calcite veins hosted in Miocene volcanic rocks (Oatman district), in Precambrian granite (Tyro and Katherine mines) or along and within Miocene felsic dikes emplaced into the Precambrian granite (Banner, Sheep Trail and Boulevard mines). These deposits are characterized by alteration haloes of local, high level silicification and pervasive clay alteration, potassium metasomatism, magnetite destruction, and sulfide mineralization (pyrite) over several square kilometers of aerial extent.
The RMI/RTP reveals at least 3 elongate 'lows' or magnetic quiet zones in areas of known hydrothermal alteration and/or gold mineralization predominantly within or along felsic dikes emplaced into the Precambrian granite or along the margin of the Frisco Graben where felsic flow domes have emanated from deep seated structures. Magnetic highs correspond to weakly propylitized Precambrian granite.
The aeromagnetic and radiometric results presented here provide outstanding insight into the upper levels of a classic epithermal district. The aeromagnetic data reveal at least three well defined magnetic quiet zones which correlate with known gold mineralization, hydrothermal alteration and/or structural corridors.
Areas of high magnetic intensity correlate with unaltered to weakly propylitized Precambrian granite. Magnetic quiet zones in the Precambrian correlate to strong propylitic alteration characterized by strong chlorite development, magnetite destruction and/or strong iron oxides formed by the oxidation of pyrite (via replacement of magnetite and ferromagnesian minerals).
The radiometric survey over the Gold Chain project was particularly useful in defining areas of potassium enrichment related to low-sulfidation gold mineralization. A pronounced anomaly of potassium enrichment is observed over the Banner, Sheep Trail and Boulevard mines which encompass the Golden Elbow area. The identification of widespread gold-bearing veins, veinlets and breccia along with strong quartz-illite-pyrite alteration in the felsic dikes support this pronounced anomaly.
Conversely, pronounced K depletion, i.e., Frisco Graben, corresponds with argillic alteration in flow dome related sub-volcanic intrusive, pyroclastic and epiclastic rocks deposited into or along this graben environment.