Project title: Geology, geochemistry, and mineralogy of the Fishtie deposit and its relationship to the Lusale Basin, Zambia
Researcher: Dr Subaru Tsuruoka
The Fishtie Cu-Co project is located in the northeast of the Lusale basin, northern Zambia. This research project studies the geology, geochemistry, and mineralogy of the Fishtie Cu-Co deposit and aims to apply the study outcomes to regional exploration activities held in the area. The project also aims to utilize the outcomes obtained from the Lusale basin as a case study to other exploration projects in the Central African Copper Belt. The Central African Copper Belt hosts ~25% and ~70% of the world's copper and cobalt resources and is known as one of the most important sources of these metals. Demand for base and critical metals is expected to increase significantly in the near future in need of more motors along with the transition to a low-carbon economy. The unique geology and high potential of the critical metals in the area attract more attention to source ethically produced critical metals from the area. The Lusale basin is located in the eastern end of the Central African Copper Belt. No systematic exploration efforts had been made in the basin before the discovery of the Fishtie copper and cobalt deposit, thereby little is known about the stratigraphy, stratigraphic architecture and nature of the copper and cobalt mineralisation in the basin. Now the basin is deemed as a new frontier for copper and cobalt resources. This research project scrutinizes new drilling data obtained at Fishtie that provide an opportunity to refine the geological model and furnish more information to the understanding of the genesis of the copper and cobalt deposit in the Lusale basin. This research project focuses on Grand Conglomérat (Mwale Formation) and Kakontwe dolomite Formation and classifies these formations into different facies. In the east of the deposit, elevated cobalt concentration has been known, however, a mineral(s) hosting the cobalt mineralisation is still unknown. This research examines intervals with elevated cobalt contents and identifies the cobaltiferous mineral(s). These outcomes obtained at Fishtie are expanded to a regional context and developed into a basin-wide genetic model of the deposit that can also provide important insight on prospectivity of the Lusale basin. As such, this research contributes not only to the scientific understanding of one of the important deposits in the area but also to practical exploration activities.
The refined geological model and distribution of the newly distinguished different facies of Grand Conglomérat and Kakontwe Formation suggest sedimentary growth faults that may have worked as conduits for mineralizing fluids which can be the next exploration drilling targets. Cobaltiferous minerals at Fishtie are identified and the understanding of the copper and cobalt mineralisation and mineral paragenesis adds important information on the geochemical signature(s) of the mineralisation and also feasibility of the deposit from a metallurgical standpoint. The utilization of the geological information of Fishtie into a regional wide context in the Lusale basin proposes a new basin-scale genetic model of the Fishtie copper and cobalt deposit as well as new prospective exploration targets.