New Copper Targets Defined at Agdz East, Morocco

Aterian Plc (AIM: ATN), the critical and strategic metals exploration and development company, is pleased to announce that an independent interpretation of the recently completed high-resolution ground magnetic data has identified multiple priority copper-silver exploration targets at its 100% owned Agdz Project (''Agdz'' or the "Project") in the Eastern Anti-Atlas Copper Belt in the Kingdom of Morocco ("Morocco").

The independent interpretation has significantly advanced the Company's geological understanding of the Project by defining the structural architecture controlling potential copper-silver mineralisation. The study has identified several priority structural targets for follow-up exploration and demonstrates strong geological similarities to the nearby Bou Skour polymetallic mining district, providing increased confidence in the Company's exploration model.

Highlights:

• Independent interpretation identifies multiple priority copper-silver structural targets.
• Survey area increased by approximately 140%, substantially expanding exploration coverage.
• Multiple kilometer-scale fault corridors interpreted as potential mineralising structures.
• Structural model demonstrates strong geological similarities with the nearby Bou Skour mining district.
• Historic rock sampling returned grades of up to 3.47% Cu and 136 g/t Ag, supporting the exploration model.
• Lithosquare AI-enabled targeting will integrate magnetic, hyperspectral and historical datasets to refine drill targets.
• Trenching is already underway with results expected in Q3.

Charles Bray, Executive Chairman of Aterian Plc, commented:

"This interpretation is a significant step forward for Agdz and reinforces our belief that the Project has the potential to host a substantial copper-silver mineralised system.

The work has moved us beyond simply identifying magnetic anomalies. We now have a much clearer understanding of the structural controls on mineralisation and have defined multiple priority targets associated with kilometre-scale fault corridors, known copper occurrences, hydrothermal alteration and historic grades of up to 3.47% copper and 136 g/t silver.

The strong structural similarities with the nearby 53 million-tonne Bou Skour deposit are particularly encouraging and provide important validation of our exploration model. With the survey area expanded by approximately 140%, Agdz now presents us with a considerably larger and more compelling exploration opportunity.

We are integrating the magnetic interpretation with hyperspectral imagery, historical exploration data and Lithosquare's AI-enabled targeting technology to rapidly refine the most prospective areas. Trenching is already underway, with results expected before the end of Q3 2026, as we work to advance the strongest targets towards drilling.

Agdz is developing into an increasingly exciting component of Aterian's Moroccan copper portfolio, with clear near-term catalysts and significant potential to deliver meaningful value for shareholders."

Independent Interpretation

The work included:

• advanced magnetic processing including Reduction to Pole, Analytic Signal and Tilt Derivative processing; and
• integration with regional geological information and previous structural studies.

The resulting geological model demonstrates that the Project is characterised by a structurally complex basement that has been affected by multiple episodes of deformation and intrusive activity.

Importantly, the interpreted structural corridors show a close spatial association with mapped quartz veining, hydrothermal alteration, fracture zones and known copper mineral occurrences recorded during field mapping and sampling.

Structural Model Supports Copper Exploration

The interpretation identifies three principal deformation systems that collectively define the structural architecture of the Project.

The study concludes that intersections between subsidiary northeast-trending structures and north-trending fault systems represent the most favourable locations for hydrothermal fluid flow and potential copper-silver mineralisation.

These structural relationships closely resemble those documented at the Bou Skour deposit (c. 53 Mt at 0.8 % Cu and 9 g/t Ag) located approximately 17 km northeast of Agdz, strengthening confidence in the Company's geological model.

Next Steps

Following completion and integration of the hyperspectral survey with the new magnetic interpretation, the Company will progress an integrated exploration programme designed to rapidly advance the newly identified structural targets towards drilling. Planned work includes:

• detailed structural geological mapping;
• systematic rock geochemical sampling;
• trenching supporting IP/Resistivity geophysical surveys over the priority target; and
• drill target definition based on the integrated geological, geophysical and AI-assisted targeting model.

Illustrations

For further information, please visit the Company's website: www.aterianplc.com or contact:

Aterian Plc:

Charles Bray, Executive Chairman - charles.bray@aterianplc.com

Simon Rollason, Director - simon.rollason@aterianplc.com

Financial Adviser and Joint Broker:

AlbR Capital Limited

David Coffman / Dan Harris

Colin Rowbury

Joint Broker:

SP Angel Corporate Finance LLP

Ewan Leggat / Devik Mehta

Financial PR:

Bald Voodoo - ben@baldvoodoo.com

Ben Kilbey