29 July 2024

Tertiary Minerals plc ("Tertiary" or the "Company")

MUPALA COPPER PROJECT, ZAMBIA

SOIL SAMPLING RESULTS

Further to the news release dated 10 June 2024, the Company is pleased to announce the completion of its soil sampling programme and receipt of field analytical results at its Mupala Copper Project in the highly prospective Kabompo Dome of the Northwestern Province, Zambia.

Key Points

·    The Mupala Copper Project is located adjacent to the Anglo American/Arc Minerals Joint Venture ("JV") Project, where Anglo American has a right to earn a 70% interest through expenditure of US$88.5 million, and 12 km west of the Company's Mukai Project.

·    Geologically located on the west side of the Kabompo Dome, in the prospective Domes Region of northwest Zambia, which is host to multiple producing copper and nickel mines, including First Quantum Mineral's Trident Project which adjoins the Company's Mukai Project.

·    A total of 684 soil samples collected on a 300m by 300m offset grid with infill sample spacing of 150m by 150m in areas of anomalous copper-in-soil.

·    Copper-in-soil anomaly approximately 1,800m long by 600m wide identified with a peak value of 422 ppm copper determined by portable X-ray fluorescence (pXRF) analysis.  The anomaly is consistent with historical exploration data and extends to the licence boundary with the Anglo American/Arc Minerals JV.

·    A sub-set of samples will be submitted for check laboratory based geochemical analysis.

Patrick Cheetham, Executive Chairman of Tertiary Minerals plc said:

"I am delighted to announce the delineation of a large and strategically located copper-in-soil anomaly at Mupala. The anomaly confirms the prospectivity of the licence which was originally indicated by historical data and its proximity to the Anglo American/Arc Minerals JV area. More work is required to determine the significance of this soil anomaly, but this is a very promising start to exploration at Mupala."

Further Information:

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 Mupala Exploration Licence 32139-HQ-LEL (the "Licence") covers 41.2 km² and is located in the Kabompo Dome region in the Northwest Province of Zambia. It is held 100% by the Company's 96% owned subsidiary, Tertiary Minerals (Zambia) Limited.

The Licence is underlain by rocks of the prospective Lower Roan Subgroup and lies directly adjacent to the Anglo American/Arc Minerals joint venture area where Anglo American has the right to earn a 70% interest through expenditure of US$88.5 million. Approximately 12 km to the east lies the Company's Mukai Copper Project and First Quantum Minerals' Trident Project which is host to the Enterprise Copper and Sentinel Nickel Mines.

Existing geological maps indicate that the licence covers some 16 km strike length of the main copper mineralised horizon in Zambia (Lower Roan Subgroup). Historical exploration records, albeit incomplete, identified a number of copper-in-soil anomalies which provided an initial focus for the Company's exploration of the Licence area.

Soil Sampling Programme

First pass soil samples were taken on a 300m by 300m offset grid over the entire Licence area with samples collected from a depth of approximately 30cm in the B-horizon of the soil profile and dry-sieved to -180 micron. A subsample of the minus soil fraction was then placed into a plastic sample cup and analysed in the field by a portable X-ray fluorescence instrument ("pXRF") to provide analytical results. A total of 452 first pass soil samples were collected. Analytical results were relayed from the field and infill sampling was conducted in the areas of anomalous copper-in-soil. Infill sampling tightened the grid to 150m by 150m in areas of anomalous copper-in-soil and a total of 232 infill samples were collected.

The main copper-on-soil anomaly is approximately 1,800m long and 600m wide with a peak value of 422ppm and is broadly coincident with a surface geochemical anomaly defined by Mwinilunga Mines in the 1960s.

A sub-set of soil samples will now be submitted for conventional laboratory based geochemical analysis as a QA/QC check on field results.

Further follow up work is planned to follow up the significance of the soil geochemical anomaly to include trenching and/or drilling.

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.