Southern Gold Ltd (ASX:SAU) is adding new ground to its portfolio with the lodging of 25 new exploration licence applications, covering more than 70 square kilometres in the historical Goseong copper-gold-silver mine district in South Korea.
The applications, with substantial tenures, cover three main past-producing mines, comprising vein systems up to a metre wide and up to 800 metres long, as well as northern and southern licence extensions to the district acquired through reconnaissance exploration of mineralisation.
Exploration activities are underway, including plans to conduct an airborne drone aeromagnetic survey to firm up promising areas for scout drill testing, which is currently planned for February next year.
The company also plans to begin diamond drilling at Goseong in the third quarter of next year on epithermal-style and intrusive-hosted/porphyry-style gold mineralisation targets.
This will be followed by diamond drilling on epithermal gold-silver projects Deokon and Dokcheon. A ground-based gravity survey is underway at Deokon and drone magnetics at Dokcheon to identify potential larger mineralised structures for drill testing.
Location map of Southern Gold projects and new Goseong Copper-Gold-Silver project.
Main copper-producing region
Goseong mining district lies in the southern region of the Masan-Goseong Metallogenic Province of the Cretaceous-age Gyeongsang Basin, which hosts about 70 gold-silver-copper-lead-zinc sheeted vein deposits as well as hydrothermal pyrophyllite-kaolinite clay deposits.
This mining district was South Korea’s main copper-producing region from 1915-1945 and 1970-1992, with some 11 small-scale producing underground mines. Historic production records are incomplete and part of the mining district is held by other companies.
The geology is dominated by volcanic-sedimentary basin sediments intruded by sub-volcanic andesite and granodiorite porphyry plugs.
Potential deeper target
Vein outcrop about 1-metre across, adjacent to footwall breccia in the historical Buyeong copper-gold-silver mine.
A vein mineralogy and research conducted by Choi et al in 1994 and Koh et al in 2003 indicate a hydrothermal-magmatic origin for the veins, which share similarities to sheeted veins systems found at the periphery of intrusive-hosted and porphyry-style copper-gold deposits. This represents a potential, deeper target for future exploration investigation, in addition to shallower vein systems.
Early sampling results from mine dumps, outcrop and sub-crop include gold up to 8.15 g/t, 265 g/t silver and copper up to 3.32%, while historical drilling conducted by Korean Resources Corporation (KORES, now KOMIR) reported results including 21 metres (not true width) at 2.5 g/t gold and 54 g/t silver near Buyeong Mine, and 6.2 metres at 54 g/t silver and 1.03% copper near Goseong Mine.
The area has not been explored using modern methods but has been the subject of some government investigation and research by KOMIR since the 1970s, including drilling, geophysical and geochemical surveys.
Southern Gold is obtaining the data from KORES for a detailed review.