The Company has recently received approval for five new licences (Tenekou, Niambaran, Pokor, Ndom and Mbe) in central Cameroon, located to the west of the regional capital, Ngaoundéré. Together with a further three new licences (Mana, Dogon and Sanga) granted to Reservoir Minerals Cameroon Sarl, a subsidiary of Oriole’s partner BEIG3, the district-scale licence package covers a contiguous land package of 3,592km2.
The licences were applied for in 2019, following an in-house, country-wide prospectivity analysis that deemed the district as having significant potential to host orogenic-type gold mineralisation. This assessment was made on the basis of host-rock geology, structural location – targeting the regional Tcholliré-Banyo shear zone (TBSZ) which is a major splay off the larger scale Central African Shear Zone. The TBSZ and its associated shears, thrusts and faults are (according to academic literature) thought to be one of the significant structural controls for gold and other mineralisation in the region.
BEIG3 and its associate Roxane Minerals Limited will have a collective 10% free-carried interest in each of the Oriole Cameroon Sarl licences up until the definition of a minimum Measured and Indicated resource of 50,000 ounces of gold; thereafter, funding will be pro-rata on a contribute or dilute basis. BEIG3 will have a 10% free-carried interest in each of the Reservoir Minerals Cameroon Sarl licences under the same terms as above, with Oriole having the remaining beneficial interest. All licences have an initial exploration term of three years and are renewable three times for a term of two years each.
An independent remote sensing study has recently been completed across the entire licence package. The study used Landsat 8 imagery and ASTER digital terrain models in order to develop preliminary regional-scale interpretations for geology, alteration and structure. Seven of the eight licences have been interpreted to cover predominantly Paleo-Proterozoic and Pan-African (Neo-Proterozoic) terranes, both of which are prospective for orogenic gold.
At the two westernmost licences, Mana and Dogon, the area is distinctly different from the east of the licence package, being topographically higher (c.1,937 metres in west to c.450m in the east). Here the structural control is dominantly north-northeast-south-southwest and is associated with more recent (Cenozoic) bimodal volcanism that is believed to overlie the older Paleo-Proterozoic to Pan -African rocks and may represent a reactivation of older structures. These interpretations are supported by a recent reconnaissance visit by the field team which confirmed that variably deformed orthogneiss units dominate the licence package, intercalated with amphibolite, quartzite and migmatite units. Shearing and quartz vein development is parallel to the TBSZ, with the veins typically forming at the contact zones between the granite and amphibolite. Locally these units are cut by younger, basaltic rocks, supporting the interpretation for bimodal volcanism. In addition to the orogenic mineralisation being targeted, this more recent volcanism highlights the potential for other styles of gold mineralisation (e.g. high-sulphidation) within the licence package, which may overprint the older system locally.
Importantly, the study has also interpreted that the TBSZ passes through at least six licences; all of the Oriole licences in the east of the package and at least one of the BEIG3 licences (Sanga) in the west, with the potential for it to be hidden by the Cenozoic cover rocks in the Mana and Dogon. A number of other important structural orientations have been interpreted within the eastern licences which may be important in controlling the emplacement and therefore location of the gold mineralisation. This is evidenced by three historical gold occurrences within the licence package – including data recorded by the French Geological Survey (BRGM) – that are all located at, or near to, the intersection of interpreted north-northwest-south-southeast trending faults and fractures with structures parallel to the main TBSZ structure.
Following a compilation of the geological, alteration and structural information across the licence package, a list of 12 priority targets have been identified and ranked as having the most potential to host gold mineralisation. During the recent reconnaissance visit, the team visited some of these targets and, from a regional and high-level perspective, they are comfortable that the remote sensing work reflects the geology and structures observed to date. The team also observed active alluvial workings in the centre of the easternmost Ndom licence, with a large number of visible gold grains being recovered. Broadly speaking, the topography of the licence package dips north-eastwards, and therefore the rivers drain to the east. The occurrence of alluvial gold in the far east of the licence package is therefore encouraging for locating a hard rock source of the gold further to the west.
A regional-scale mapping and stream sediment sampling programme is planned for later in H1-2021. This work will be conducted alongside the existing ongoing programmes at Bibemi and Wapouzé.
