The Company’s 96% owned subsidiary Tertiary Minerals (Zambia) Limited holds a 90% joint venture interest in the Jacks Copper Project Large Exploration Licence number 27069-HQ. This is currently held by local Zambia partner Mwashia Resources Limited, but it has been agreed to incorporate a joint venture company to hold the project and tertiary now holds an option to purchase Mwashia’s 10% interest in the project.
Exploration Licence 27069-HQ-LEL covers 141.4 sq. km. and is located 85km south of Luanshya in the Central African Copperbelt.
The Central African Copperbelt is the world’s largest sediment-hosted stratiform copper province. It includes at least 14 giant deposits within a 400-km arcuate trend of Neoproterozoic rocks that spans the border of Zambia and the Democratic Republic of the Congo.
The rocks hosting the known copper mineralisation in the licence comprise basal Katangan Supergroup sediments. This Supergroup includes the Lower Roan Subgroup, the main copper mineralised rock sequence in the Central African Copperbelt.
Mineralisation occurs within the southern limb of a large asymmetric synclinal fold structure that has an east-west trending axis and a westerly plunge. The original Jacks Prospect sits close to the nose of the syncline at its eastern end.
During drill planning, the Company created a 3D model of the mineralisation based upon interpretation of historical exploration data which suggests that copper occurs in either two separate mineralised horizons which may be discrete mineralised zones or one refolded horizon. The results of recent drilling broadly confirm this interpretation. The two mineralised zones, now named the North Zone and South Zone, dip steeply north toward the syncline axis.
In October 2022 Tertiary carried out a programme of soil sampling to follow up unresolved copper-in-soil anomalies defined during wide spaced soil sampling by previous operators including Cyprus-Amax and First Quantum Minerals, as well as to guide follow-up drilling on the Jacks main prospect.
Over 2,000 B horizon soil samples were initially collected over four separate areas covering 11.5 sq.km. Samples were collected at 40m intervals on lines spaced 200m apart and preliminary elemental analysis of the samples was carried out in the field using a portable x-ray fluorescence (pXRF) analyser.
Results of analysis have delineated significant copper and copper:scandium anomalies on Grids C & D each over several hundred meters, and with peak values ranging from up to 525ppm copper.
As a guide to the significance of soil sampling results, the Company notes that B horizon soil anomalies for freely drained soils in the vicinity of various ore zones at current and past producing mines on the Copperbelt have thresholds in the range 50 to 150ppm copper, averaging 80ppm copper and peak values in the range 100-450ppm copper and averaging 210ppm copper. In addition, published data for the giant Sentinel copper deposit (>1 billion tonnes grading 0.51% copper, located close the Company’s Mukai Project in northwest Zambia) shows that the median copper value for soil samples collected over the sub-cropping expression of the orebody was 120ppm and only one soil sample exceeded 500ppm copper.
Soil sample analytical results therefore compare favourably with soil anomalies in the vicinity of various ore zones at current and past producing mines on the Copperbelt.
