Mapping confirms that silicification and argillic alteration resulting from hydrothermal activity has affected the Early to Middle Miocene Besshodake Andesite and associated pyroclastic rocks and lacustrine sediments throughout the historical Unoya Mine area…
Beyond the Headline
Irving reports that geological mapping in the historical Unoya Mine area in the Shika Project, Japan shows widespread silicification and argillic alteration in Miocene andesitic volcanic rocks. High-grade quartz-vein float occurs both around the historical Unoya mine and in a second area about 1 km south, suggesting Irving may have a more extensive en echelon vein system related to a potential shear structure underlying the area. The standout new float sample returned 62.3 g/t Au and 604 g/t Ag; this sample had dark silver-rick bands known as “ginguro” bands. Thirteen (13) of 56 quartz/vein-float samples collected in 2026 are reported to have returned >1 g/t Au.
Drone magnetics has delineated an approximately 2.5km by 1.0 km subdued magnetic zone coinciding with altered rocks and higher-grade gold-bearing vein float. Irving interprets this as magnetite destruction caused by hydrothermal alteration. Two principal clusters of high-grade float could represent separate portions of an en echelon vein array. Irving interprets the present exposure as being at a relatively high level in the epithermal system, implying that the more prospective boiling/mineralized interval could remain preserved at depth.
The JV which comprises Newmont 60%, Sumitomo 12.5% and Irving 27.5% is considering reconnaissance drilling in 2027, potentially with relatively short 300–500m holes. Final potential drill-hole locations, orientations and depths will be determined following integration of the geological, rock-geochemical, soil-geochemical and geophysical datasets. Soil assays from 548 samples are also reported to be still pending.