The Beopseongpo project is located approximately 40 km east-northeast of Gwangju city in the southern Jeolla Province, in the south west of the country. The region hosts several known gold occurrences including the current Eunsan-Moisan operating goldmine to the south. This region is an ongoing focus for exploration by Southern Gold for epithermal Au-Ag deposits. Southern Gold has engaged experienced independent epithermal consultant and ex-Ivanhoe Geologist, Craig Panther to undertake field exploration and project generation targeting.
Previous work was originally completed around the Beopseongpo Project area in 1999 by Indochina Goldfields Ltd with the area reinvestigated in early 2000 as part of a general field review of hydrothermal clay deposits and associated vein systems on islands surrounding the Jeolla-nam do coastline by Ivanhoe Mining. It was identified as a high-level Low-Sulfidation epithermal vein system, with well-developed lattice quartz after calcite and was traced for more than three kilometres.
Detailed ground assessment work by Southern Gold in late 2017 identified Beopseongpo as one of several very prospective epithermal gold-silver targets with no known drilling to date. The new tenements (Beopseongpo 29 and 30), granted in July 2018, are a significant addition to the Southern Gold portfolio with ~4 km traceable strike length, 1m plus vein widths within a ~30 m wide alteration zone and the preservation of possible mineralised vein intervals (LS epithermal mineralisation model) suggesting that it is an extensive system.
Initial rock chip sampling of vein outcrop and float material, returning grades up to 21.8 g/t Au and 19 g/t Ag (float); 3.0g/t and 1 g/t Ag (outcrop) (Table 1).
Table 1: Significant Assays (>1g/t Au or >1g/t Ag) from rock samples at Beopseongpo.
A second phase of detailed mapping and rockchip sampling was undertaken in April 2019. Five major vein zones have been identified although there is likely more that are hidden under cover rocks. Vein segments have been individually mapped up to 500 metres in strike extent and on a combined basis up to 2,570 metres. These vein zones are ~20 metres wide with individual vein widths commonly in excess of 1m true width.
All five vein zones have returned weak to moderate anomalous gold-silver values with peaks of 31.9g/t Au and 23.5g/t Ag – although these results come from clasts that have been ripped up and transported in the fault from deeper parts of the mineralised system.
Vein zones have been named (from north to south): Golden Palm, Lotus (including North, South and Extended sections), Hand of Faith, Phoenix and Enigma vein zones (Figure 2). Of these, Golden Palm, Lotus North and Hand of Faith represent immediate drill targets (Photos 1 and 2).
Table 2: Significant Assays (>1g/t Au) from second phase of mapping and rock sampling at Beopseongpo.
Figure 1: Beopseongpo Project with simplified geology and vein zone map, illustrating the extensive footprint of the mineralised zone and multiple drill targets such as Golden Palm, Lotus North and Lotus South.
The April 2019 field work has also uncovered two historical Japanese occupation-era adits (Figure 1) as evidence of small-scale historical mining in the area. Anecdotal evidence suggests that at least one of the mines was worked on multiple levels along a strike length of approximately 150m although the mine was closed after the Korean war and is currently sealed with concrete.
The important observation to be made from the presence of the mine at Beopseongpo is that it reinforces the technical thesis that the surface expression of the mineralised zone is of an uneroded upper level of a low-sulphidation epithermal system with economic grades of gold potentially 100m to 500m below the present day land surface.
A maiden drilling program was completed at Beopseongpo in September 2019, with 866.33m of diamond drilling. 653.53m was completed at ‘Lotus North’, followed by a further 212.8m at ‘Hand of Faith’. The latter was the most promising Prospect with observations from drill core showing that the target was clearly intersected, displaying abundant epithermal veining with individual, predominantly veined, zones up to 7 m in true width with high-level epithermal textures, within broader zones of up to 50 metres true width. Numerous low-sulphidation epithermal multi-phase quartz-adularia+-pyrite +/- fine sulphide dusting veins were intersected within intensely altered (propylitic distal and argillic vein proximal) basement host. Vein textures encountered include: colloform banded, chalcedonic flood, bladed quartz pseudomorphs after calcite, comb, veined breccias, vein breccia, saccharoidal and mesocrystalline.
At ‘Lotus North’ only minor epithermal veins were encountered, and the current interpretation is that the main target is dipping to the east rather than the west. This was contrary to what was expected from the limited outcrop in the area and caused the designed holes to pass sub-parallel to the target. Further geological investigation is required.
Final assays are expected during November at which point the program will be summarised in more detail.
Depending on the results of the first drilling program, further drilling is planned for the first half of 2020. This will extend and infill the initial drilling undertaken as well as test the other veins identified during the surface mapping and sampling.
Further mapping and sampling will be undertaken on the two blocks to the south (Gaumdo_11 and Gaumdo_21, Figure 1), once access has been granted, to explore for further extensions of the vein system in this region.
Beopseongpo project is defined by a wide vein zone that has an interpreted strike length of over 3.8 km. This Low-Sulfidation adularia-sericite type epithermal vein system (akin to the SAU owned Weolyu project) is localised proximal to faulted contact between basement gneiss/schist and cretaceous rhyolite volcanics.
Veining is hosted within both basement granitic gneiss/schist and rhyolitic dome tuff facies volcanics (Figure 1, Photo 1 and 2). The vein corridor is up-to 30 metres wide in known exposed width (Figure 1 and Photo 2) and hosts at least three quartz veins between one and two metres in width, with numerous subordinate parallel vein sets.
Textural descriptions of quartz veining within the prospect area has helped understand the LS epithermal zonation across the vein system. Structural measurements obtained from in situ outcrop, provided strike and dip of the quartz veining and the faulted contact of the basement schist-gneiss and younger rhyolite volcanics. These measurements indicate that the system is over 4 km in strike length extending over the two applications and dips 70-85 degrees to the west.
Gold-silver anomalism show relationships associated with quartz textural and absolute elevation differences (the original paleo-watertable) along this extensive vein system. The northern vein segment with the most anomalous gold values is at a lower elevation than the central and southern vein segments.
Photo 1: KRS203071. Precious metals below detection limits. Multiphase hydraulic vein breccia with quartz pseudomorphs after bladed calcite. Central Beopseongpo Vein Segment.
Photo 2: KRS203043. Precious metals below detection limits. Vein sample comprised solely of quartz pseudomorphs after bladed calcite, indicative of flash boiling. Central Beopseongpo Vein Segment.
The North and Central Vein sections are comprised of polyphasal, massive to crudely banded mesocrystalline, crystalline and chalcedonic quartz, hosting zones of pronounced hydraulic brecciation (Photo 1). Black to grey fine-grained unresolvable sulphides are present, and bladed quartz pseudomorphs after calcite are common (Photo 2). The latter is an indicator of a gas-rich, boiling hydrothermal fluid and quartz textures in general are indicative of dynamic formation at a level no more than fifty metres below the paleo-watertable. Host rhyolites are pervasively silica-illite ± adularia-clay altered, and the presence of sulfide is indicated by extensive limonitic, goethitic and local haematitic oxide stain development (Photo 3).
Photo 3: KRS203141. 1.56 g/t Au, <2 g/t Ag Limonitic to haematitic recrystallised chalcedonic quartz with a cockade band rimmed rhyolitic wall-rock fragment. North Beopseongpo Vein Segment.
Photo 4: KRS203059. 0.13 g/t Au, <2 g/t Ag Hydraulic vein breccia comprised of chalcedonic quartz vein fragments cemented by chalcedonic silica. Note wisps of fine-grained grey-black sulphide & limonitic band fragments. Central Beopseongpo Vein Segment.
The South Vein section is characterised by voluminous crystalline, saccharoidal to lesser mesocrystalline quartz vein float, with pronounced quartz pseudomorphs after bladed calcite (Photo 4). The weakly anomalous gold assay results reported for the South Vein area is significant considering the very shallow exposure level that the quartz texture observations indicate.