First Quantum Minerals Ltd has a 100% interest in the Trident Project (Sentinel and Enterprise mines), 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 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’.
Deposit Type
The Sentinel deposit is a stratabound, sediment hosted Cu-Ni-Co sulphide deposit located to the southeast of the Trident project area, with the deposit hosted within the structurally thickened, northwest dipping carbonaceous meta-pelitic rocks known as ‘Kalumbila phyllite’. Copper mineralization at Sentinel is limited to the strongly deformed phyllite unit, with rare low-grade mineralization extending only 1 to 2 meters into the hanging and footwall from the contact. The ore-body strikes approximately east-west for 11 kilometers and mineralized 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. The oxidized horizon, up to approximately 70 meters in depth, contains non-primary sulphide copper minerals, predominantly chalcocite, and tarnished chalcopyrite. The top five to 15 meters from the surface is typically leached of copper or contains mixed refractory copper and trace oxide minerals.
Mineralization
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.
Alteration
Coarse centimetre scale, often euhedral, blebs of kyanite alteration are common throughout the phyllite host rock. Kyanite is generally associated with copper mineralization, though kyanite intensity does not correlate to copper grade.
Biotite, phlogopite, and sericite alteration is common, and typically concentrated along bedding and foliation planes. Metre-scale lenses of intense and pervasive sericite alteration occur sporadically along the contact between the phyllite and hangingwall schist. These intensely altered lenses are devoid of mineralization.
Round, mm to cm scale, cordierite poikiloblasts are scattered within the phyllite matrix. Carbonate alteration is common in the footwall phyllite, proximal to the footwall schist contact, and to a minor extent within the phyllite matrix.