REG - Tertiary Minerals - Drill holes show silver - Target A1, Mushima North

Tertiary MineralsAnnouncement

24/09/2025 07:00

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RNS Number : 5127A  Tertiary Minerals PLC  24 September 2025

 

24 September 2025

Tertiary Minerals plc

 ("Tertiary" or the "Company")

 

New drill holes demonstrate the northerly continuation of thick, near surface
silver mineralisation over a 300m width at Target A1, Mushima North

 

Tertiary Minerals plc (AIM: TYM) is pleased to announce drilling results for a
further three holes from the Phase 2 follow-up drill programme at Target A1 at
its Mushima North Project in Zambia ("Mushima North" or the "Project").

The analytical results from the new drillholes support the previously reported
northern continuation of the thick near surface mineralisation defined by only
one drill hole until now, extends over a width of approximately 300m. Silver
mineralisation has now been intersected in drilling over a 350m by 300m area,
and remains open to the north, south and at depth.

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

 

Highlights:

 

·   Drill intersections include:

·   64m at 26 g/t Ag, 0.13% Cu and 0.21% Zn from 2m downhole (Hole
25TMNAC-027).

§ Including: 20m at 36 g/t Ag, 0.13% Cu and 0.27% Zn from 46m downhole.

·   44m at 39 g/t Ag, 0.17% Cu and 0.37% Zn from 8m downhole (Hole
25TMNAC-028).

§ Including: 15m at 63g/t Ag, 0.13% Cu and 0.56% Zn from 33m downhole.

§ And: 16m at 1.59% Zn from 56m downhole.

·   Mineralisation, including higher grade zones, remains open to the
north, south and at depth.

·   Results include the highest grades of zinc (3.35%) and antimony (0.21%)
intersected to date from certified laboratory analytical results on the
Project.

·   Additional drill hole results expected in the coming weeks testing both
northern and southern continuation of mineralisation.

·   Initial mineralogical/metallurgical work now underway.

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

 

"We are delighted to report further extension of the silver mineralisation at
Target A1. These results support the continuation of the near surface, thick
mineralisation to the north over a substantial width. The silver
mineralisation footprint is at least 350m by 300m and remains open to the
north and south, and at depth.

"The new results continue to define higher grade silver intersections within
the broader silver-copper-zinc mineralisation, for example 15m at 63 g/t
silver within 44m at 39 g/t silver in hole 25TMNAC-028. The grade continuity
along and between holes is excellent and the results further support our bulk
tonnage, open pit silver exploration model.

"The additional analytical results expected over the coming weeks are from
holes that tested the continuation of the mineralisation to both the north and
south. In addition, the initial mineralogical/metallurgical studies are now
underway. We believe this could represent a significant discovery for the
company and eagerly await these results and I look forward to updating our
shareholders in due course."

 

Phase 2 Drill Programme

As previously reported, the Phase 2 drill programme consisted of 1,116m of
combined Air Core ("AC") and Reverse Circulation ("RC") drilling along a
series of east-west drill lines spaced between 100m and 250m apart,
north-south. Holes were collared approximately 100m apart along the east-west
lines and drilled to the maximum depth possible at the time based on the drill
rig capabilities and geological ground conditions (the bit refusal depth). The
deepest drill hole in this programme was 99m and the average hole depth 70m.
Combined Phase 1 and 2 drilling covers a surface footprint of approximately
1,680m by 550m.

The three drill holes now being reported, and described below, are located on
the same east-west drill traverse and form a four-hole line with the
previously reported hole 25TMNAC-026. This traverse, 8507150N, lies
approximately 225m to the north of Phase 1 drill traverse 8506925N and the
holes were designed to test the continuation of mineralisation to the north
from drill line 8506925N.

·    25TMNAC-027: Located approximately 100m west of 25TMNAC-026 and
drilled to the east (inclined -60°) to a downhole depth of 66m. The hole was
designed to test the continuation of the mineralisation to the north from
drill line 8506925N.

·    25TMNAC-028: Located approximately 100m west of 25TMNAC-027 and
drilled to the east (inclined -60°) to a downhole depth of 72m. The hole was
designed to test the continuation of the mineralisation to the north from
drill line 8506925N.

·    25TMNAC-029: Located approximately 100m west of 25TMNAC-029 and
drilled to the east (inclined -60°) to a downhole depth of 99m. The hole was
designed to test the continuation of the mineralisation to the north from
drill line 8506925N.

 

 

Table 1. Phase 2 (Target A1) analytical results (three holes only, other
analytical results from remainder of the drilling programme awaited).
Equivalent grades ("Eq") are for illustrative purposes only.

 

Note to Table 1 and 2:

·    Calculated intersections (downhole, true widths unknown) are weighted
averages based on silver, using a cut-off grade of 10 g/t Ag. Intervals start
and end with ≥10 g/t Ag and with up to 3m consecutive internal dilution
allowed.

·    Silver values rounded to whole numbers.

·    EOH means End of Hole.

·    CuEq (%) and AgEq (g/t) are the copper and silver equivalent grades,
respectively, and were calculated assuming commodity prices of Cu: US$4.5 lb,
Ag: US$40 oz, Zn: US$1.2 lb and 100% recovery. No information on beneficiation
recoveries is available at this stage. These are for illustrative purposes
only.

·    Gram metres for silver are the silver values (g/t) multiplied by the
intervals (m).

 

Target A1

Target A1 is a large copper-in-soil anomaly (3.1km by 1.7km) with copper
values up to 302ppm (per Portable X-Ray Fluorescence, "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 (e.g. 59m at 0.2% Cu from
10m downhole, hole 24TMNAC-004). Higher grade copper mineralisation within
these broader zones was also returned (e.g. 6m at 0.58% Cu within 33m 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 silver mineralisation has now been confirmed to extend for approximately
350m by 300m laterally and to a depth from near surface to 84m. However, the
silver mineralisation remains open-ended both to the north, south and at
depth. The mineralisation at Target A1 is associated with a massive,
haematitic and carbonaceous silty-sandy conglomerate. Where visible, copper
mineralisation is in the form of secondary copper minerals malachite and
chrysocolla. The mineralogical speciation of silver and zinc is yet to be
determined. 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.

Drilling results (previously reported) from the Phase 1 and 2 drilling
programmes are presented in Table 2 below.

 

Table 2. Selected silver intersections from Phase 1 and 2 drilling from Target
A1. Equivalent grades ("Eq") are for illustrative purposes only. See Table 2
for notes.

 

 

Mushima North Project

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

The Project's western boundary lies 20km to the east of the Kalengwa
copper-silver mine in northwest Zambia, one of the highest-grade copper
deposits ever to be mined in Zambia (approximately 4 million tonnes at 5.2%
copper and 40-80 g/t silver). In the 1970s, high-grade ore, reportedly
averaging approximately 11% 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.

Several prospective targets have been defined thus far within the Project
based on reviews of historic geochemical and geophysical survey data against
the current exploration model developed by Tertiary (Targets A1, A2, B1, B2,
B3 and C1). At the end of the summer 2024, Tertiary completed an initial
(Phase 1) 25 AC drill hole programme (1,274m) to test parts of geochemical
(copper-in-soil) anomalies at Targets A1 and C1. This limited and shallow
drilling indicated wide downhole intervals of largely coincidental copper,
zinc and silver mineralisation at Target A1. The other geochemical and/or
geophysical targets (A2, B1, B2 and B3) are yet to be drill tested.

The Project is held under a technical cooperation agreement with First Quantum
Minerals Limited ("FQM"), which allows Tertiary to benefit from FQM's historic
exploration data in the area, as well as FQM's geological team's extensive
experience and understanding of the area's geology. The agreement is
non-binding to any further agreement and there are no commercial restrictions
for Tertiary, nor does FQM have a right of first refusal over the Project.
Further details can be found in the news release of 15 September 2022.

 

Sampling, Analysis and QAQC

Sampling from the drilling programme 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 were initially analysed on site using a pXRF analyser for zinc and
copper. 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 ("QA") procedure. Given the nature of
the unprepared sample and point analysis, this method was 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 were then
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) were inserted and monitored as part of
the Quality Assurance Quality Control ("QAQC") protocol.

Reported drill hole intersection thicknesses are downhole thicknesses and true
thicknesses are unknown. Intersections are weighted averages based on silver,
using a cut-off grade of 10 g/t Ag with up to 3m consecutive internal dilution
and intervals starting and ending with ≥10 g/t Ag.

 

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
 Peterhouse 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 Nevada and in Zambia.

 

 

 

Figure 1. Location map of Target A1 showing soil sample results for copper and
zinc and the collar locations for the 2024 and 2025 drill programme.

 

 

 

Figure 2. Drill cross-section 8507150N (location on Figure 1) showing
analytical results for silver for drill holes 25TMNAC-027, 25TMNAC-028 and
25TMNAC-029. Analytical results for 25TMNAC-040 is awaited. See Table 1 notes
for further information.

 

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