The Achmmach Tin project is owned by Atlas Tin SAS, a joint venture company comprising Atlantic Tin Ltd (Atlantic Tin) (75%), Toyota Tsusho Corporation (20%) and Nittetsu Mining Co Ltd (5%).
On the 5th August 2024, Atlantic Tin completed the acquisition of Société Anonyme d’Entreprises Minières (SAMINE). The SAMINE project is being acquired by Titan Tin, a 100% owned subsidiary of Atlantic Tin.
Atlantic Tin is the operator of the project.
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Summary:
Deposit Type
Geologically, the Achmmach sector is part of the Moroccan Massif Central which constitutes the largest Paleozoic unit of the Moroccan meseta which extends from the coast of the Atlantic in the West to the foot of the Middle Atlas (Azrou-Khénifra region) in the east. To the north it is limited by the Saïs basin (Meknes basin) and to the south it disappears under the plateaus of the phosphates.
The Paleozoic terrains are intruded by numerous Hercynian granite massifs, late-tectonics, the main ones being from the West to the East: the massifs of Zaër, Oulmès and Ment as well as the granite points of Moulay Bouazza, El Hammam and J. Aouam. The general structure, produced by the major Hercynian phase, of the entire Massif Central is summarized in a succession of anticlinorium’s and synclinoriums separated by mega faults which played at the basin boundary in the Carboniferous, and in shear during the late-Hercynian compressions.
The Achmmach tin deposit is hosted within a sedimentary sequence of turbidite beds that were probably deposited in a deep marine environment resulting from suspensions currents depositing the material at the base of a slope. The beds are thin-bedded and graded-bedded cyclic beds. The depositional environment varied over time allowing more proximal, sandy and coarser grained material to be incorporated.
Following deposition, these marine clastic sediments were subjected to a period of northwest– southeast directed ductile deformation and shortening which led to the formation of broadly southeast (~140°) verging, tight and, in places, sheared folds with west-north-west (~300°) dipping axial planes and east-northeast (~070°) striking fold hinges.
Subsequent to folding, the clastic host rocks underwent a second episode of deformation which was dominated by dextral transpressional deformation. During this period, northwest (~340°) dipping tourmaline-silica breccia corridors formed. These are marked by intense poly-phase brittle deformation, alteration and cementation.
After the formation of tourmaline-silica breccias, but prior to the emplacement of mineralisation, the area underwent a period of extension associated with the intrusion of magmatic dykes of felsic and mafic composition that are conformable to the host rocks.
The Achmmach tin deposit is an epigenetic vein-stockwork-breccia style deposit which is associated with a strongly boron enriched paleo hydrothermal system. It is comprised of fine-grained cassiterite with associated minor sulphide minerals in a tourmalinised sandstone/siltstone host. It is interpreted as being hosted by two cross-cutting swarms of tourmaline-altered zones: a series of east-west striking sub-vertical zones described as “feeders” and a stacked series of oblique gently to steeply northdipping “branches».
Mineralization
Achmmach mineralisation is localized in two sub-parallel E-NE striking lodes named the Meknès and Sidi Addi trends, separated by approximately 500m. Meknès comprises the largest part of the Mineral Resource. Mineralisation is developed within the tourmaline-silica altered metasediments. Tin mineralisation occurs primarily as cassiterite with minor stannite. It is pure in composition and does not carry significant trace elements. It is an epigenetic vein-stockwork-breccia style deposit.
It is comprised of fine-grained cassiterite with associated minor sulphide minerals in a tourmalinised sandstone/siltstone host. The 1.6 km strike extent of the mineralisation system is hosted by sequences of folded and metamorphosed shales and sandstones. The lodes in Meknes form a 300m wide array across strike with individual lode structures ranging in width from 1m to 30m. Tin mineralisation occurs primarily as breccia infill and quartzcassiterite veins and has been defined in diamond drill holes to a vertical depth of up to 600m below natural surface. The bulk of the known mineralisation intersected by the current drilling occurs between 1,000m RL and 700m RL. Mineralisation remains open at depth and along strike.
Mineralisation is interpreted to have been introduced by a period of extensional deformation which led to moderately dipping, northwest trending (~340°) mineralised shears/breccia intervals. These strongly mineralised shear bands cut the early tourmaline breccias at low angles. The footwall and hanging wall adjacent to these shears host sub-vertical cassiterite veins. The density of these veins inferred to be a function of the proximity (spacing between) of the shear bands.
Vein cross-cutting relationships indicate that the mineralisation process occurred over a prolonged period including several pulses of precipitation that are marked by a changing composition in the mineralisation source. As a result, later and cross-cutting veins lack tin mineralisation but are enriched in arsenic, copper and other base metal sulphides, carbonates and fluorspar.
Dimensions
Overall tin mineralisation at the Achmmach Meknes Trend extends 1.6 km in strike length, is 300 m wide and extends from the surface to 600 m below the surface. The high-grade parts of the Meknes and Fez zones, which are of the most interest, are 400 m in strike length, 200 m wide and located from 150 m below surface to 400 m below surface.
Tin mineralisation at Achmmach Sidi Addi Trend extends 1.5 km in strike length, individual lodes are up to 8 m wide, and extend from the surface to 200 m depth. Mineralised intercepts less than 2 m downhole were not included in the wireframes.