Overview

Mine Type	Underground
Stage	Construction
Commodities	Tin
Mining Method	Longhole open stoping Unconsolidated rockfill
Production Start	...
Mine Life	5 years (as of Jan 1, 2022)
Shapshot	Tin concentrate production from the new Mpama South plant is imminent with first ore having been successfully introduced on 28 April 2024. The final plant commissioning phase is now underway and should see a ramp-up in tin concentrate production during May 2024. The Mpama South underground development continues on target and ore stockpiles are being established ahead of the plant. The underground mine is ready to feed the plant at targeted rates.
Related Asset	Bisie (Mpama North)

Deposit type

• Vein / narrow vein

Summary:

The tin deposit is a cassiterite-bearing vein system adjacent and possibly distal to an underlying source granite. From the composition of the mineralization, it was concluded that the mineralization has a low temperature origin, with a probable granitic source. Fluorine and lithium are absent from the ore forming fluids and base metal sulphides are scarce in the cassiterite. The deposit has up to 0.5% rare earth elements (REE) and very high-grade tin (with some sample assays reaching >60% Sn). This may indicate the source granite to be at depth below the surface.

The age of the Bisie cassiterite is 1053 Ma to 1068 Ma – it therefore may have been precipitated penecontemporaneously with deposition of the host sediments. Ore forming processes at Bisie are, therefore, either related to a granite that is also circa 1060 Ma old and as yet undiscovered, or they are associated with synsedimentary exhalative processes and unrelated to a granite intrusion. In the latter case, Bisie mineralization may be more closely analogous to Neves Corvo in Portugal, where a tin-rich, stratiform, massive sulphide deposit has formed, than it is to deposits such as San Rafael in Peru.

The first phase of exploration diamond drilling was completed at Mpama South in May 2015 and comprised 16 drillholes (plus three re-drills) drilled from east to west and spaced 50-100m apart on seven drill lines for 3,364metres. This early phase of drilling served both as a confirmatory/discovery campaign to test below artisanal mine workings and as a delineation exercise to ascertain scale and grade at Mpama South. No Mineral Resources were declared.

In December 2020, drilling restarted at Mpama South to define a Mineral Resource and delineate the further extents of the mineralization which were still open on strike and at depth. As at the effective date of this report, 34,963.55m in 140 diamond drillholes have been drilled and logged at Mpama South, with drilling still on-going presently. Some of these drillholes were drilled from west to east from drill platforms in the footwall initially but the majority was drilled from east to west and spaced 40 – 80m apart.

The strike length of mineralization has grown substantially at Mpama South since drilling recommenced in December 2020 to around 1,150 metres. The Mpama South mineralization intersected by drilling now extends northwards up to the southern end of the Mpama North Mine. A cross-cutting faulted area known as ‘The Wedge’ separates the two deposits. Alphamin believes that Mpama South and Mpama North formed one contiguous deposit, which is separated by the NW-SE striking ‘Wedge’ fault dipping steeply towards the SW.

The fault appears to be dextral and observations of the projected outcrop indicate that is has offset the main zone of mineralization at Mpama South westwards of the zone at Mpama North by ~75 metres. The fault zone itself is ~15 metres wide and appears to contain discontinuous cassiterite mineralization of a highly brecciated and low-grade nature. Further drilling in the wedge area from underground at Mpama North is underway at the time of writing.

Depth of mineralization at Mpama South is observed from surface in weathered outcrop to an RL elevation of about 350 metres, equivalent to approximately 450 metres vertical extent. Artisanal miners targeting cassiterite in the weathered outcrop excavated adits horizontally and vertically to a potential maximum depth of 70m.

3D Mineral Resource modelling delineated seven continuous discrete tin (with minor copper) mineralized zones at Mpama South in a stacked/parallel configuration. MZ1 and MZ2 represent the two main zones of the Mineral Resource and are continuous for 900 m and 650 m along strike respectively, and both have a down dip extent of 350 m and vary from as little as 1 metre up to 14 metres thick. Four zones are below the main zones and towards the south (MZ3 – MZ6) and one is in the hangingwall. They range in thickness from 1 – 9 metres with average thicknesses of typically 1.0 – 1.5 metres for MZ3 – MZ5, 4.0 metres for MZ6 and 0.5 metres for MZ7.

The two main zones of mineralization (MZ1 and MZ2) have similar average tin grades at a 0.5% Sn cut-off of (2.22% and 2.11% respectively). The smaller, footwall zones (MZ3 to MZ5) are higher in tin grade with averages ranging from 3% to 4.41% while MZ6 and MZ7 are lower in tin grade, with an average of 0.63% and 1.07% respectively.

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Job Title	Name	Profile	Ref. Date
.......................	.......................		Apr 22, 2022