Guinea – To date, Volcanic Gold Mines has completed a total of almost 3 000 m of reverse-circulation (RC) and diamond drilling, and over 15 000 m of air-core drilling at Mandiana and at lands recently optioned from West African Mining Associates SARL (WAMA).
The exploration programme to date has resulted in the expansion of the strike potential of the Yagbelen resource at Mandiana by approximately 1 000 m, and its lateral potential by up to 500 m.
RC and diamond drilling were completed within, and in the immediate surroundings of the inferred mineral resource at Yagbelen, as previously defined by Sovereign Mines of Africa in 2013 when it drilled 119 RC and diamond drill holes for a total of 16 624 m at the property. Drill testing included the four zones (Yagbelen, Foulouni, Damantare and Woyondjan) that now form the basis of the mineral resource calculation.
Understanding the geological controls
As well as serving to infill the resource, the RC and diamond drilling has also allowed Volcanic to gather extremely valuable information on the geological controls on mineralisation. On the basis of work completed to date, gold mineralisation is seen to occur preferentially in a series of bedded sandstone units; these units are repeated in all holes, and their characteristics will serve as a key targeting tool in Volcanic’s forthcoming resource drilling program.
Air-core drilling has been successfully deployed in the identification of extensionsto the north, east and south of the Yagbelen resource, in which regard it has defined a further 1 000m of strike potential. Initial air-core results illustrate the strike continuation of a strongly anomalous feature extending approximately 500m to both the north and south of the resource, as well as laterally, 500m to its east. These results clearly demonstrate the efficacy of air core drilling in the Mandiana district, and on this basis, Volcanic has defined a very significant near-term resource drilling target.
Results of air-core drilling from a further southward 1 250 m strike extension to the reported grid, as well as an infill block covering approximately 500 m of strike remain outstanding. Air-core drilling has been performed in grid-like fashion on a series of “fences” established at 100-200 m intervals, along which inclined holes have been drilled at 40-50 m spacings. This rapid, low-cost approach to exploration has been designed to provide detailed and accurate information on near-term resource targets. The air-core drilling is ongoing.
Reverse-circulation and air-core drilling of the Farabakoura deposit at the WAMA project has also been completed, its purpose being to confirm the high grade historic results and to define zones of extension to this mineralisation.
Sampling and testing
Drill chip sampling at Mandiana followed a standardized protocol to ensure the collection of representative and unbiased quantities of material from each sample. Samples were collected from Volcanic’s Mandiana field operations by SGS Mineral Services of Bamako, Mali, and were transported directly to the assay facilities thereof, at which they were analysed for gold by means of fire assay.
In January 2017, Volcanic acquired an indirect 75% interest a Guinean entity, Guiord SA, which owns 100% of the Mandiana project in Guinea. The remaining 25% interest in the Mandiana project is held by Guinea state mining company SOGUIPAMI.
In April 2017, Volcanic entered into a binding letter agreement to acquire 80% of WAMA, a private Guinean company, the landholdings of which together adjoin the entire length of the southern boundary of, and lie within the same mineralised trends as Volcanic’s Mandiana project.
The Mandiana and WAMA projects are underlain by geology comparable to that of many other Birimian-age volcano-sedimentary sequences in West Africa, in which gold mineralisation typically exhibits a strong relationship with major structural and hydrothermal zones. At both the Mandiana and WAMA projects the gold mineralisation associates with a network of quartz veins which appear to relate to such zones, and is located at major lithological and structural breaks.
In the near vicinity and of very similar geological character is AngloGold Ashanti’s Siguiri gold mine, as well as other significant gold deposits and mines in the neighboring area including Hummingbird Resources’ Yanfolila project, Avnel Gold Mining’s Kalana property, and Avocet Mining’s Tri-K project.