REG - Tertiary Minerals - Drilling Update at Target A1, Mushima North

Tertiary MineralsAnnouncement

13/11/2025 07:00

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RNS Number : 3287H  Tertiary Minerals PLC  13 November 2025

 

13 November 2025

Tertiary Minerals plc

 ("Tertiary" or the "Company")

 

 Drilling Update at Target A1, Mushima North Project, Zambia

Best pXRF result to date: 95m intersection grading 0.4% copper

pXRF silver grades up to 246g/t

 

Tertiary Minerals plc (AIM: TYM) is pleased to provide an update on work
programmes at Target A1 and preliminary results from portable X-Ray
Fluorescence ("pXRF") analysis of drill samples.

Target A1 is a polymetallic (silver-copper-zinc) prospect, part of the Mushima
North Project ("Mushima North" or the "Project") and is located in the
prospective Iron-Oxide-Copper-Gold region of Zambia. Target A1 is located
28km to the east of the historic Kalengwa copper-silver mine which is
currently under redevelopment.

 

 

Highlights:

 

Ø 4 holes completed in this Phase 3 drill programme for a total of 481m with
the deepest hole having been drilled to a depth 127m. Remaining programme put
on hold due to the early start of unusually heavy rains.

Ø Initial results extremely positive, with visible secondary copper
mineralisation observed over a 20m interval and sulphide mineralisation
observed towards the base of the holes.

Ø High pXRF silver values of up to 246 g/t and broad intervals (>20 g/t)
in line with previous pXRF results (the pXRF analysis for silver is
semi-quantitative, these values are therefore indicative only. Silver
intervals will be released following laboratory analysis).

Ø Drill intersections include (pXRF analysis for copper and zinc only,
downhole widths, true widths unknown):

o  95m at 0.41% Cu from 10m downhole (hole 25TMNRC-043).

§ Including: 47m at 0.58% Cu from 58m downhole, and

§ 25m at 0.75% Cu from 80m downhole, and

§ 8m at 1.13% Cu from 89m downhole.

o  30m at 0.17% Cu from 12m downhole (hole 25TMNRC-044).

§ Including: 25m at 0.23% Cu from 51m downhole, and

§ 3m at 0.6% Cu from 60m downhole.

 

Ø Initial mineralogy identifies native silver and native copper, along with
other copper-bearing minerals.

Ø JORC Exploration Target work to now commence.

 

 

 

Richard Belcher, Managing Director of Tertiary Minerals plc, commented:

"Whilst the pause of the planned drill programme due to the onset of heavy
rains earlier than anticipated is frustrating, the preliminary results from
the first few holes are extremely encouraging, have extended the area of known
mineralisation in the north and at depth, and support our current exploration
model. We will now bring forward programmes originally planned for after the
drilling in Q1 2026 to maintain the positive momentum going forward.

"These programmes include the JORC Exploration Target work, which will provide
valuable guidance on the resource potential of Target A1 in terms of a range
of tonnages and grades, as well as further mineralogical studies to better
understand the mineralisation and deportment of the metals of interest.

"The above studies will continue to advance this exciting project and the
results of these studies, along with the laboratory assay results from the
four holes in this programme, will be communicated in further press releases
in the coming months. This will all feed into the next drill programme planned
to commence at the start of the dry season next year and will support our aim
of producing a Maiden Mineral Resource Estimate in 2026.

"I look forward to updating shareholders on these results in due course as
well as providing updates on our wider exploration portfolio in Zambia and
elsewhere."

 

Phase 3 Drill Programme

A programme of approximately 1,000m Reverse Circulation ("RC") was planned as
part of Phase 3 drilling. Initially drilling proved very promising, but heavy
and earlier than expected rains have resulted in the pause of this programme
until after the rains, most likely in March/April 2026. Four vertical holes
were completed with a maximum depth of 127m testing the northern extent of the
currently open-ended mineralisation footprint.

 

The four drill holes now being reported, and described below, are located on
two east-west drill lines, 8507275N and 8507375N (see Figure 1 below. Drill
line 8507375N represents the most northern drill traverse drilled to date.

·    25TMNRC-041: Located on a two drill-hole line with 25TMNRC-042. The
drill hole was drilled vertically to a downhole depth of 112m. The hole was
designed to test the continuation of the mineralisation to the north from
drill line 8507275N.

·    25TMNRC-042: Located on a two drill-hole line with 25TMNRC-042. The
drill hole was drilled vertically to a downhole depth of 127m. The hole was
designed to test the continuation of the mineralisation to the north from
drill line 8507275N.

·    25TMNRC-043: Located on a three drill-hole line with 25TMNAC-038 and
25TMNRC-044 (drill line: 8507275N). The drill hole was drilled vertically to a
downhole depth of 121m. The hole was designed to test the continuation of the
mineralisation to the east from drill hole 25TMNAC-038.

·    25TMNRC-044: Located on a three drill-hole line with 25TMNAC-038 and
25TMNRC-043 (drill line: 8507275N). The drill hole was drilled vertically to a
downhole depth of 121m. The hole was designed to test the continuation of the
mineralisation to the west from drill hole 25TMNAC-038.

Figure 1. Location map of Target A1 showing soil sample results for copper and
zinc, and the collar locations for the previous (Phase 1 and 2) and Phase 3
drilling programme (both planned holes: grey circles, and drilled holes: red
circles).

 

 

The pXRF results for copper (and zinc) of the above holes are provided below,
and the intervals will now be sent to the certified independent laboratory for
multi-element analysis, including silver.

 

 

Table 1. Phase 3 pXRF intersections for copper and zinc at Target A1.

 

 

Note to Table 1:

·      Calculated intersections (down hole, true width unknown) are
weighted averages based on zinc (intervals start and end with ≥0.2% Zn, and
the average grade cut-off is 0.2% Zn and allow for up to 3m internal dilution)
or copper (intervals start and end with ≥0.1% Cu, and the average grade
cut-off is 0.1% Cu) and include up to 3m of internal dilution allowed).

·    Reported values were produced using a pXRF analyser to test
unprepared samples and as such are of a preliminary nature but provide an
indication of potential mineralisation.

 

 

These results provide further evidence for higher-grade copper mineralisation
in the north of the target area and the continuation of the silver
mineralisation. Whilst the pXRF results for silver are not sufficiently
accurate to allow grade intervals to be reported, the pXRF silver results from
this Phase 3 programme are, in general, consistent with the pXRF results
recorded from drill holes in this area during Phase 2 drilling which, on
analysis at an independent laboratory, returned reportable silver
intersections.

 

The current surface footprint of the mineralisation (approximately 450m by
400m) remains open still to the north/northwest and south/southeast, while the
maximum vertical depth of oxide mineralisation has increased by an additional
21m, from 84m to 105m (Figure 2). The potential for primary sulphide
mineralisation, underneath the near-surface oxide mineralisation is, as yet,
largely untested.

 

Figure 2. Drill cross-section 8507275N (location shown on Figure 1) showing
analytical results for silver and selected copper values for drill holes
25TMNAC-038 and 25TMNAC-039. See Table 1 notes for further information.

 

Figure 3. Field sample from drill hole 25TMNRC-043 showing visible secondary
copper mineralisation (the green mineral, predominantly malachite).

 

 

Mineralogy

 

Two samples from mineralised intervals in Phase 2 drill holes were submitted
to Petrolab Ltd in the UK for mineralogical descriptions.

Both the sample compositions and textures suggest a volcanoclastic
(tuff-tuffaceous) host rock to the mineralisation within the oxidised,
near-surface zone. Mineralisation (with quartz and carbonates) is associated
with hydrothermal fluids and deposition of mineralisation with vugs and
fractures in the host rocks. The copper minerals observed are primarily native
copper (Cu) and cuprite (Cu2O) within the vugs and fractures. Silver (Ag) was
only observed as native silver as blebs within the vugs or later infilling of
fractures within quartz, carbonates and the copper minerals. The main
sulphides observed were pyrite (FeS) along with trace amounts of chalcopyrite
(CuFeS(2)), chalcocite (Cu(2)S), sphalerite ((Zn,Fe)S) and pyrrhotite
(Fe((1-x))S) (Figures 4 & 5).

Part of the summary report by Petrolab Ltd states: "The ore mineralisation and
degree of limonitisation is consistent with gossanous weathering of a well
mineralised tuffaceous volcaniclastic deposit. Ag  silver  and Cu  copper 
have likely been remobilised from prior existing sulphides and concentrated
through supergene enrichment processes."

 

 

 

Figure 4. Reflected light images from the mineralogical sample TYM_TS001.

Left image: A partially filled vug in the volcanoclastic with native copper
(Cu) and iron oxidation and large anheadral crystals of cuprite (cpr) with
silver (Ag) infilling fractures.

Right image: A partially filled vug within the volcanoclastic with cuprite
(cpr), blebs of sphalerite (sph), chalcopyrite (cpy) and native silver (Ag).

 

 

Figure 5. Reflected light images from the mineralogical sample TYM_TS002.

Left image: Pyrite(py) grain now heavily oxidised (FeO) with a thin alteration
rim of chalcocite (cc). Native silver (Ag) occurs as infill within fractures
within the sulphides.

Right image: Pyrite crystal within the volcanoclastic matrix with local
chalcocite (cc) alteration. Note the native silver (Ag) crystal next to the
pyrite.

 

Target A1

Target A1 is a large copper-in-soil anomaly (3.1km by 1.7km) with copper
values up to 302ppm (per pXRF) associated with a 1.7km by 0.5km zinc- and
coincidental 1.3km by 0.3km silver-in-soil anomaly.

Phase 1 drilling in 2024 targeted the copper-in-soil anomaly and returned
broad but generally low-grade copper mineralisation as reported in the news
release dated 28 October 2024 (e.g. 57m at 0.20% Cu from 14m downhole, hole
24TMNAC-004). Higher grade copper mineralisation within these broader zones
was also returned (e.g. 6m at 0.58% Cu within 35m at 0.21% Cu, from 22m
downhole, hole 24TMNAC-024). Drilling over the silver- and zinc-in-soil
anomaly (drill line: 8506925N) identified wide and thick, near surface silver
mineralisation associated with low-grade copper and/or zinc mineralisation.

The Phase 2 drill programme (1,116m), as discussed above, targeted the silver-
and zinc-in soil anomaly. The silver mineralisation has now been confirmed to
extend approximately 450m northwest-southeast and by 400m northeast-southwest
and to a depth from near surface to 84m and it remains open-ended both to the
north/northwest, south/southeast and at depth.

The mineralisation at Target A1 is associated with a massive, haematitic and
carbonaceous silty-sandy conglomerate. Copper mineralisation observed to date
is predominantly in the form of secondary copper minerals malachite,
chrysocolla and cuprite. Native copper, chalcocite and chalcopyrite are also
observed. Silver mineralisation is so far only observed as native silver and
zinc mineralisation is observed as sphalerite. Elevated bismuth (up to 991
g/t), and the critical metals antimony (up to 0.21%) and gallium (up to 40
g/t) are also associated with the mineralisation in places.

 

Mushima North Project

The Mushima North Copper Project (Licence 27068-HQ-LEL) is held through Group
company Copernicus Minerals Limited ("Copernicus"), which is 90% owned by
Tertiary Minerals (Zambia) Limited and 10% by local partner, Mwashia Resources
Limited.

The Project lies 20km to the east of the Kalengwa copper mine in northwest
Zambia, one of the highest-grade copper deposits ever to be mined in the
country. In the 1970s, high-grade ore, average approximately 11% Cu copper,
was trucked for direct smelting at other mines in the Copperbelt. The Kalengwa
mine is currently under redevelopment and is expected to produce 15,000 tonnes
of copper annually.

Numerous other geochemical and/or geophysical targets (A2, B1, B2, B3, C2) are
yet to be drill tested. Many of these are located within 12km of Target A1.

 

Figure 6. Geological map of the Mushima North Project showing the locations of
the priority targets within the licence and their distance out from Target A1
based on 5 km radius rings.

 

Sampling, Analysis and QAQC

Sampling was undertaken at 1m intervals, and two subsamples were collected
from each interval using a riffle splitter: one for potential laboratory
analysis, the other for future reference.

Samples have been initially analysed on site using a pXRF analyser for zinc
and copper and, more recently, silver. Analysis protocol included multiple
point (three) analyses per sample (unprepared sample analysed through a thin
plastic sample bag) and the inclusion of Certified Reference Material, blanks
and duplicate samples as part of an internal Quality Assurance procedure.
Given the nature of the unprepared sample and point analysis, this method is
used as a preliminary exploration technique to provide an approximate
quantitative measure of copper and zinc mineralisation only.

Samples from selected drill holes based on the initial pXRF results will now
be sent to the independent laboratory ALS Global in South Africa for analysis
for a range of elements using a four-acid digest, method code ME-ICP61
(including silver, copper, zinc, bismuth, antimony and gallium). QA samples
(Certified Reference Material, duplicates, blanks) will be inserted and
monitored as part of the QAQC protocol.

Reported drill hole intersection thicknesses are down-hole thicknesses and
true thicknesses are unknown as the geology of the drill area is still
uncertain. Intersections are weighted averages on zinc (using a cut-off grade
of 0.2% Zn) or copper (using a cut-off grade of 0.1% Cu) with up to 3m
internal dilution and intersections starting and finishing with 0.1% Cu or
0.2% Zn, respectively.

 

Further Information:

 Tertiary Minerals plc
 Richard Belcher, Managing Director  +44 (0) 1625 838 679
 SP Angel Corporate Finance LLP, Nominated Adviser and Broker
 Richard Morrison/Jen Clarke         +44 (0) 203 470 0470
 AlbR Capital Limited, Joint Broker
 Lucy Williams/Duncan Vasey          +44 (0) 207 469 0930

 

Market Abuse Regulation

The information contained within this announcement is deemed by the Company to
constitute inside information as stipulated under the Market Abuse Regulation
(EU) No. 596/2014 as it forms part of UK domestic law by virtue of the
European Union (Withdrawal) Act 2018 ('MAR'). Upon the publication of this
announcement via Regulatory Information Service ('RIS'), this inside
information is now considered to be in the public domain.

 

Cautionary Note Regarding Forward-Looking Statements

The news release may contain certain statements and expressions of belief,
expectation or opinion which are forward looking statements, and which relate,
inter alia, to the Company's proposed strategy, plans and objectives or to the
expectations or intentions of the Company's directors. Such forward-looking
statements involve known and unknown risks, uncertainties, and other important
factors beyond the control of the Company that could cause the actual
performance or achievements of the Company to be materially different from
such forward-looking statements. Accordingly, you should not rely on any
forward-looking statements and, save as required by the AIM Rules for
Companies or by law, the Company does not accept any obligation to disseminate
any updates or revisions to such forward-looking statements.

 

Competent Persons Statement

The technical information in this release has been compiled and reviewed by
Dr. Richard Belcher (CGeol, EurGeol) who is a qualified person for the
purposes of the AIM Note for Mining and Oil & Gas Companies. Dr. Belcher
is a chartered fellow of the Geological Society of London and holds the
European Geologist title with the European Federation of Geologists.

 

About Tertiary Minerals plc

Tertiary Minerals plc (AIM: TYM) is an AIM-traded mineral exploration and
development company whose strategic focus is on energy transition metals. The
Company's projects are all located in stable and democratic, geologically
prospective, mining-friendly jurisdictions. Tertiary's current principal
activities are the discovery and development of copper and precious metal
mineral resources in Zambia and Nevada, USA.

 

 

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