The Odienné project lies in the northwest of Côte d’Ivoire within the Denguelé Region, close to the borders of Mali and Guinea. The project consists of the granted ‘Odienné East’, and two licences in application; Odienné Ouest and Danane, which are 350 km apart. These licences are held under a separate joint venture with ANGET-CI - a local company who have a 10% stake in the licences.
The Odienné project area has been subject to previous first pass exploration, initially through a joint venture between SODEMI and Randgold Resources, carried out between 1994 and 1996. The JV completed broad-spaced, shallow soil sampling for gold and base metals over the greater portion of the project area and followed up with pitting and trenching.
The work revealed several coherent moderate-order (>150 ppb) gold in soil anomalies over a strike of up to 500 m. Sample averages from the trenches returned 115 ppb Au over 16 m in saprolite and 1,175 ppb over 16 m in rhyolite with visible quartz veinlets. The higher intercept includes a 17,300ppb (17.3 gram/tonne) sample. Rock chip samples from veins in the workings returned values of 10.4 grams/tonne, 4.07 grams/tonne and 4.6 grams/tonne.
Geologically, the project area lies on a splay of the regional scale Sassandra fault which forms the partition between the Archean Kenema Man domain and the Proterozoic Baoule-Mossi Domain. Rocks in the project area consist of a felsic/acid volcanic to mafic greenstone belt intruded by a series of later plutons of varying size and orientation. The intrusions range from intermediate to mafic in composition.
Figure 8: Left, Example of Odienne Artisanal Mining Site-deep shafts on interpreted steeply dipping and plunging high grade lodes. Right, Geologic map of the main Savanné Artisnal mining area - the photo to the left was taken in Area 1.
Within the greenstone’s ductile deformation is common and artisanal mining in the area is often associated with brittle ductile contrasts, where the sheared greenstones come into contact with the intrusives. Mineralisation and alteration around these workings showed gold hosted in quartz with generally biotite schist variably in contact with volcanics, volcaniclastics and intrsuives. Silica alteration is dominant with weaker chlorite and sericite, with a sulphide association (pyrite dominant, + chalcopyrite and arsenopyrite). The Danane permit lies on the same trend as the Endeavour Ity Mine (7.5 Moz) which lies on a Birimian inlier associated with a regional scale structure that passes through Liberia and Côte d’Ivoire.