All deposits on the Mana property are characterized as typical West African, shear- hosted orogenic gold deposits.

The WonaKona deposit is hosted in relatively wide corridors of silicification with disseminated mineralization hosted in a sheared package of alternating fine grained metasediments and metavolcanics. At Yaho, the mineralization is associated with a strongly sericitized arenite, locally conglomeratic located within a wider deformation zone affecting metavolcanics and other fine grained sediments. The three southern deposits (Nyafé, Fobiri and Fofina) are hosted in dominantly sheared and silicified volcanic rocks hosted within quartz rich veins. These veins tend to be richer but narrower. Finally, the newly discovered Siou Zone is composed of a series of shear zones hosting free-gold bearing quartz veins located along a contact between a sedimentary sequence and a felsic intrusive.

The Wona-Kona mineralization occurs as disseminated pyrite and arsenopyrite in highly deformed and silicified meta-sedimentary of meta-volcano-sedimentary rocks. Locally, silicification is so intense as to form massive quartzitic bodies, which are commonly preserved within the saprolitic horizon. In some extreme cases blasting is necessary to mine within the saprolite horizon.

The mineralization at Nyafé, Fofina and Fobiri is also associated to pyrite and arsenopyrite disseminated on the edge of millimetric veinlets of microcrystalline grey quartz. Folded carbonate veinlets cross the mineralization.

Disseminated pyrite and arsenopyrite is omnipresent throughout the sericitized arenite which hosts the Yaho Zone but higher percentages are observed within four separate zones which also hosts the better gold grades. Gold values are consistently anomalous throughout the entire host unit (above 100 ppb). The delineated subparallel gold zones within the arenite can measure more than 50 meters thick, sometimes accounting for more than 50% of the entire host unit.

The mineralization at Siou occurs at or near the contact between a sedimentary unit to the west and a granodioritic intrusive to the east where series of shear zones containing quartz veining and sericite alteration over thicknesses of 5 to 25 meters are observed. The Siou Zone and the Nine Zone vary from less than one meter to close to 20 meters in width, with an average of between 4 and 4.5 meters. The shear zones dip approximately 45 to 60 degrees to the east.

Two mining methods will be employed at the Mana operation. Open pit mining will continue to be used at Wona/Kona and part of the Siou ore zone, and at Fofina and Nyafé. Following identification of the ore at depth, underground mining will be employed in the southern part of the Siou deposit.

Open Pit Mining
Open pit mine production at Mana averages approximately 7,500 t/d of ore, mainly from the Wona and Siou pits, that can be blended with ore from the other open pit sources up to a maximum of 8,000 t/d for processing in the mill. The Kona pit has been mined out and backfilled.

Underground Mining at Siou
Two underground mining methods will be used: long hole (longitudinal retreat and transversal) and cut and fill mining; these were selected because of the inclination of mineralized lenses and ore (stockwork) thickness. Long hole mining will be used when a stope can be mined economically above a dip of 50o degrees and by cut and fill below 50o . Most of the areas where the Siou orebody is located in the hanging wall will be mined cut and fill. Consolidated backfill and loose rock will be used to ensure safe ore recovery in long hole mining. For cut and fill mining, pivot ramps will be driven from the main access ramp.

SEMAFO envisages underground production at Siou reaching capacity in the second quarter of 2020. Detailed engineering will take place through the first half of 2018. It is expected that the mining contractor will be mobilized in the third quarter of 2018, with portal preparation and underground development initiated immediately.

ROM ore is loaded by a WA600 front end loader onto a static grizzly screen to handle slabby material. A rock breaker reduces the oversize material that remains on the static screen (625 X 665 mm). Fine material drops into a 150 tonne capacity ROM bin. The ore is then extracted from the bin by a primary apron feeder (1,524 mm X 7,000 mm) and fed to a vibrating scalper (1,500 mm X 4,000 mm) to further separate the fines. Coarse material from the scalper feeds directly into a 36" X 48" (950 mm X 1,250 mm) single toggle jaw crusher. The crusher produces a product with a P80=100 mm, at a rate of 400-500 wtph to allow for a 17 hour per day crushing operation.

The grinding circuit consists of a Semi Autogenous Grinding mill (SAG) in close circuit with a vibrating screen and a pebble crusher. The 7.92 meter diameter X 2.74 meter Allis Chalmers SAG is equipped with 2,387 KW variable speeds motor and operates between 10-15% ball charges depending on ore hardness. Variable speed contro ........