Gold miner West African Resources (WAF) reported last month that resource definition drilling has confirmed the geological model, with extensive zones of gold mineralisation intercepted at the Toega deposit in Burkina Faso.
“Resource definition drilling at the 1.3-million-ounce Toega gold deposit has confirmed the geological model intercepting extensive zones of free-milling gold mineralisation including 79 m at 2 g/t gold and 56 m at 1.6 g/t gold in drillhole NAK21-DD014. Social and environmental programmes are progressing to plan, with the environmental and social impact assessment to be submitted to government for environmental approval in the fourth quarter of 2021,” explained WAF executive chairperson Richard Hyde.
“Geotechnical and metallurgical core samples have also been shipped to Perth, in Australia, for testwork. The definitive feasibility study with updated resource estimate and maiden ore reserve for Toega is on track for release in the first quarter of 2022,” he added.
WAF has completed a resource definition reverse circulation and diamond drilling programme at the recently acquired Toega gold project. The programme also included diamond core holes to provide geotechnical and metallurgical testwork samples. A total of 118 holes were drilled for 15514 m.
Resource definition by WAF drilling has confirmed the geological model developed by previous owners B2 Gold, with multiple holes intercepting mineralisation of similar geometry, grade and tenor. Drilling also intercepted mineralisation near surface, outside the scoping study $1 400/oz openpit shell, which will be incorporated into future mining studies.
Extensive gold mineralisation was confirmed in the main zone, up to 150 m wide and 200 m deep with NAK21-DD014 returning 79 m at 2 g/t gold from 70 m and 56 m at 1.6 g/t gold from 159 m.
Significant results from the Toega resource definition drilling include: NAK21-DD004: 29 m at 3.4 g/t gold from 125 m; NAK21-DD011: 17 m at 3.8 g/t gold from 158 m; NAK21-DD015: 12 m at 4.4 g/t gold from 147 m; NAK21-RC024: 12 m at 6.1 g/t gold from 108 m; and NAK21-RC026A: 22 m at 5.0 g/t gold from 80 m.
The Toega deposit is hosted in Paleoproterozoic-aged Birimian rocks and is located close to the intersection of the northeast-striking Tenkodogo greenstone belt and the regionally significant, north- northeasterly-trending Markoye Fault corridor.
The Markoye Fault runs north-northeast over 400 km from northern Ghana, through Burkina Faso into southern Mali and Niger and is associated with a number of significant gold deposits including Sanbrado (WAF); B2 Gold’s Kiaka; Orezone’s Bombore; Nordgold’s Tarparko and Bourroum, and IAMGOLD’s Essakane.
The project area is underlain by metasedimentary rocks which have undergone regional deformation during the Eburean Orogeny and metamorphism to greenschist to lower amphibolite facies. There are three main lithologies including shale, biotite-rich psammite and sericite-rich psammite (schistose metagreywacke and metasandstone), with the bulk of the ore grade mineralisation (by volume) occurring in the more sericite-rich metasediments.
Alteration mineralogy comprises silica, potassium feldspar, biotite, sericite and locally epidote. The dominant sulphide associated with gold mineralisation is pyrrhotite (with subordinate pyrite) which can reach up to 5% in mineralised zones.
Structurally, Toega occurs in a much lower strain environment in contrast to Sanbrado, with mineralisation occurring in gently east dipping mineralised packages.
The core of the deposit plunges moderately to the north-north-east. Some mineralisation exhibits replacement textures, while there is also evidence of steeper mineralisation associated with quartz-potassium feldspar veining. The majority of gold mineralisation in the Toega deposit occurs in fresh rock.