29 June 2022

Tertiary Minerals plc

("Tertiary" or "the Company")

Positive Drilling Results From Jacks Copper Project

Tertiary Minerals plc (LON: TYM), the AIM traded mineral exploration and development company, whose strategic focus is on energy transition metals, is pleased to announce that the Company has received positive laboratory assay results from its first drill programme at the Jacks Copper Project ("Jacks") in Zambia, where it is earning a 90% joint venture interest.

·    Significant copper mineralisation intersected in all four diamond drillholes:

22JKDD01:           13.5m grading 0.9% copper from 77.5m downhole, including

              3.0m grading 1.7% copper from 79.5m, and

                                3.5m grading 1.2% copper from 87.0m

22JKDD02:             7.0m grading 0.6% copper from 54.0m, and

  3.0m grading 0.8% copper from 191.0m

22JKDD03:             6.0m grading 1.8% copper from 105.0m, including

  4.0m grading 2.4% copper from 106.0m

22JKDD04:           14.0m grading 0.8% copper from 27.0m, including

  2.0m grading 1.7% copper from 27.0m and

  5.0m grading 1.0% copper from 35.0m.

·    Copper mineralisation has now been intersected over a strike length of 350m and remains open along strike and at depth.

·    Planning is now underway for further evaluation of the historical copper soil anomaly that extends over a strike length of c.16km within the licence area.

·    Tertiary has given notice to joint venture partner Mwashia Resources Ltd ("Mwashia") that it has now earned a 51% interest in the Jacks Project licence, and has duly exercised its option to continue earning up to a 90% joint venture interest.

·    Jacks Project is one of five licences areas in Zambia where Tertiary has the right to earn a 90% interest from Mwashia.

Commenting today, Executive Chairman Patrick Cheetham said:

"We are delighted to be reporting these positive results. The impressive copper hits in all four holes in our first drill programme confirms and builds on the historical results from the Jacks Project, and demonstrates continuity of copper mineralisation over an open-ended 350m strike length. Given that the Jacks Prospect lies within a 16km long soil geochemical anomaly, it is clear we are dealing with an exciting target with considerable potential. In the meantime, our local partner, Mwashia Resources Ltd, has made good progress on the environmental permitting required for exploration to start on the four other licences within our Zambian portfolio. We look forward to a busy and productive work programme during this dry season."

For more information, please contact

Note to Editors

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

Market Abuse Regulation

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (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.

Detailed Information

The Jacks Prospect lies within Exploration Licence 27069-HQ-LEL which covers 141.4 km² and is located 85 km south of Luanshya in Zambia.

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 northern limb dips 15°-25° to the south demonstrated by historic drilling as well as from mapped outcrop. Previous work reports that the dips on the southern limb are variable between 60° to the north and vertical with local overturning. The detailed geometry of the syncline and interpreted parasitic folds is poorly understood and further interpretation of orientated drill core is required. Within the licence area past exploration has defined a 15km long soil geochemical anomaly that broadly follows the southern and northern limbs of the syncline. The Jacks Prospect sits close 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 mineralise zones or one refolded horizon. The results of drilling broadly confirm this interpretation. The two mineralised zones, now named the North Zone and South Zone, dip steeply north toward the axis of the syncline.

Further detailed information on the exploration history and the background to the current drill programme can be found in the Company news releases dated 16 June 2022.

Phase 1 Drill Programme

In May 2022, Tertiary contracted Ox Drilling to conduct a diamond drilling programme with geological supervision and drill management contracted to Zambian consulting group GeoQuest Limited. The purpose of the Phase 1 drill programme was to confirm the presence of, and assess the continuity of,  copper mineralisation reported in the 1990s.

Four holes were completed for a total of 746m of drilling, two each on two separate traverses spaced approximately 150m apart. During the drill programme core orientation was carried out together with preliminary analysis of core using portable XRF ("pXRF") to provide real-time interpretation of drill intersections and facilitate the positioning of subsequent holes.

Drill core was cut on-site and 186 samples, along with internal QA/QC samples, were delivered to SGS Laboratories in Kalulushi for independent laboratory-based analysis. Drill core samples were prepared and analysed using methods PRP90¹ and ICP42S¹, respectively.

Analytical Results

Drill hole details and significant SGS assay results are shown in Table 1 and Table 2, respectively.

Hole 22JKDD01 was drilled to intersect the north dipping South Zone mineralisation where historical drillhole KJ12 (see news release dated 2 August 2021) intersected 9.0m grading 0.9% copper. 22KJDD01 was drilled to 164.2m and intersected 13.5m grading 0.9% copper from 77.5m downhole including two higher grade intersections² of 3.0m grading 1.7% copper from 79.5m and 3.5m grading 1.2% copper from 87m.

Hole 22JKDD02 was drilled approximately 110m north of 22JKDD01 to intersect  mineralisation reported in historical drillhole JKD1 which intersected both mineralised zones (13.8m grading 1.0% copper from 112.7m downhole and 2.8m grading 1.0% copper from 229.5m downhole). 22JKDD02 was drilled to 250.9m and intersected 7m grading 0.6% copper from 54m downhole, significantly higher in the hole than expected, however no copper was observed visually or via pXRF where the North Zone had been predicted. The South Zone mineralisation was, however, intersected with 3m grading 0.8% copper from 191.0m downhole in a position that which correlates with the historic drilling.

Hole 22JKDD03 was a step-out hole and was drilled approximately 150m east of 22JKDD02 to a depth of 260.2m. Copper mineralisation was first intersected from 105.0m downhole with 6.0m grading 1.8% copper, including a higher-grade interval of 4.0m grading 2.4% copper from 106m downhole.

22JKDD04 was another step-out hole, drilled approximately 160m east of 22JKDD01 and 170m south of 22JKDD03. It was drilled to test along strike from 22JKDD01 and beneath the copper-in-soil anomaly which, on this traverse, was relocated by infill pXRF soil analysis conducted whilst the drilling programme was ongoing. A broad mineralised zone was intersected with 14.0m grading 0.8% copper from 27m downhole, including two higher grade intersections of 2.0m grading 1.7% copper from 27m downhole and 5.0m grading 1.0% copper from 35.0m downhole.

Drill holes 22JKDD03 and 04, as well as stepping out from 22JKDD01 and 22KJDD02, have demonstrated the presence of mineralisation towards historical drillhole KJD10 which intersected 24.0m grading 1.3% copper and 13.6m grading 0.4% copper in a deeper portion of the mineralised system, some 210m and 230m below surface respectively.

The Company considers that the presence of copper mineralisation has now been demonstrated at Jacks over a 350m strike length and to depths up to 230m vertically below surface, and is open in all directions. Copper mineralisation may be thickening closer to the fold nose, as evidenced by historical drillhole KJD10. To the west a continuous copper-in-soil anomaly extends along the southern limb of the syncline for several kilometres within the licence area and has been tested by only limited very wide spaced drilling with a number of holes intersecting copper mineralisation that remains to be followed up (e.g. 6.5m grading 1.1% copper from 297.5m downhole in 1999 drill hole KJD02).

The Company is currently undertaking a more in-depth review of the drill date with a view to commencing additional fieldwork and drill planning.

Drill Plans and Drill Sections are available to view on the Jacks Project webpage at  https://www.tertiaryminerals.com/jacks-project-zambia .

Table 1: Drill Hole Details

Table 2: Analytical Results^1&2

Notes:

1.    SGS, Kalulushi - Drill core samples were prepared using method code PRP90, where samples are dried, crushed to 90% passing 2mm and a 250g split pulverized to 85% passing 75µm. Samples were analysed by method code ICP42S, a 26 element multi-acid digest with ICP-AES finish.

2.   Drill intervals being reported are thicknesses of mineralisation down-hole at cut-off values of 0.2% copper and 0.5% copper for lower and higher-grade intervals, respectively. Mineralisation is currently interpreted as steeply dipping and true thicknesses are estimated to be approximately 70% of the above reported thicknesses.

3.   The information in this release has been reviewed by Mr. Patrick Cheetham (MIMMM, M.Aus.IMM), Executive Chairman of Tertiary Minerals plc, who is a qualified person for the purposes of the AIM Note for Mining and Oil & Gas Companies. Mr. Cheetham is a Member of the Institute of Materials, Minerals & Mining and also a member of the Australasian Institute of Mining & Metallurgy. 

4.   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.