First Quantum Minerals Ltd has a 100% interest in the Trident Project, through a subsidiary operating entity, FQM Trident Ltd. (formerly Kalumbila Minerals Ltd.)
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Summary:
The Trident Project Area, including the Sentinel and Enterprise deposits, is located on the western end of the Lufilian Arc.
Sentinel
Sentinel is located to the southeast of the Trident Project area. The deposit is hosted within structurally thickened, northwest dipping carbonaceous meta-pelitic rocks known as ‘Kalumbila phyllite’.
The Sentinel deposit is a sediment-hosted stratiform copper deposit. Mineralisation is predominantly primary sulphide copper, with sheet-like horizons of ore dipping north at 20-30o . The mineralisation is parallel to dominant foliation, within the structurally deformed carbonaceous phyllite host.
Copper mineralisation at Sentinel is limited to the strongly deformed phyllite unit, with rare lowgrade mineralisation extending only 1-2 metres into the hanging and foot-wall from the contact. The ore-body strikes approximately east-west for 11 km and mineralised horizons dip 20 to 30 degrees in a northerly direction, generally parallel to the dominant foliation.
The dominant copper-bearing mineral is chalcopyrite and typically occurs within bedding/foliation parallel quartz-kyanite-carbonate mm-scale veinlets. Within folded zones, veinlets tend to be thicker (mm scale), blebby, and more irregular, and often contain a relatively higher proportion of chalcopyrite. Late sulphide-bearing cross-cutting veinlets and disseminated or blebby chalcopyrite are less common.
The oxidised horizon, up to approximately 70 m in depth, contains non-primary sulphide Cuminerals, predominantly chalcocite, and tarnished chalcopyrite. The top 5-15 metres from surface is typically leached of copper, or contains mixed refractory copper and trace oxide minerals.
Nickel-cobalt mineralisation exists predominantly in the form of cobalt-pentlandite, with trace amounts of vaesite. Apart from rare sporadic metre-scales lenses (likely related to structures) the Ni-Co mineralisation occurs as a discrete horizon within the ‘footwall’ phyllite. ‘Footwall’ phyllite refers to the lowermost portion of phyllite that tends to be barren, or very low in copper mineralisation. Ni-Co mineralisation is best developed in the NE extent of the deposit, proximal to the Kalumbila Fault.
Enterprise
Enterprise is located in the northwest of the Trident Project area (Figure 7-3), and is hosted within a sequence of sedimentary units which form part of the Katangan System.
Enterprise is a hydrothermal nickel deposit with mineralization hosted in a sequence of shale and siltstone units. These units have been preferentially mineralized due to rheological and geochemical interactions with mineralizing fluids. Enterprise mineralization has an unusual lack of spatial control from mafic intrusives and the primary source of nickel remains unclear.
Nickel sulphide minerals include vaesite (NiS2), pentlandite (Fe,Ni)9S8, millerite (NiS), nickeliferous pyrite ([Fe,Ni]S2), bravoite ([Ni,Fe]S2) and carrollite (Cu[Co,Ni]2S4). Sulphide mineralization occurs within, or as an alteration halo to quartz-kyanite ± talc veins and vein breccias. Sulphides are concentrated within altered black shales and to lesser amounts in proximal siliciclastic rocks. Hydrothermal mineralization appears related to a series of deep seated structures having an extensional regime. The dominant control on the location of mineralization is a combination of structure, rheology and chemistry. Black shales host most mineralization and are a favourable rheology for brittle deformation, as well as being a reductant for oxidised hydrothermal fluids. Other siliciclastic units can be mineralized, but typically at lower concentrations than the black shale. Minor copper mineralization underlies nickel mineralization located 350m below surface. Copper grades of up to 2.80% have been intersected by drilling with intersepts of 5 m having 1.27% Cu (ENTDD0120) and 14 m having 1.72% Cu (ENTDD0019) as examples. Copper minerals include chalcopyrite, bornite and chalcocite.