Aterian Plc Regulatory News (ATN)

16 October 2023

Operational Update:

Significant Sedimentary-Hosted Copper Extensions,

Tata Project, Morocco

Aterian Plc("Aterian" or the "Company")

Aterian Plc (LSE: ATN), the critical and strategic metal-focused exploration and development company, is pleased to announce the results, including 7.02 % copper ("Cu"), from additional fieldwork conducted on the Company's Tata Project (the "Project"). The Project, covering 154.4 km2, is located within the western Anti-Atlas Mountains of the Kingdom of Morocco ("Morocco") and lies 30 km south of the Company's Azrar copper-silver project. The Tata Project is one of 17 copper, silver and base metal projects owned by Aterian, covering 897 km2 in Morocco within established current and historic mining districts.

Highlights:

· Project located in central Morocco within the western Anti-Atlas, a region considered highly prospective for sedimentary-hosted copper mineralisation

· Latest sampling reports up to 7.02 % Cu.

· Copper mineralisation is identified within two stratigraphic horizons and is visible on surface.

· Combined strike length with visible copper mineralisation extends over 18 km.

· A data review indicates that a strike length c.26 km within the prospective Adoudou Formation remains untested, with at least a further 9 km within the lower Cambrian Tata Group sediments.

· The project lies 50 km southeast of the Tizert Copper-Silver development project, with a similar geological setting

· 30 km south of the Company's Azrar copper project.

· Project located close to good infrastructure.

Charles Bray, Chairman of Aterian, commented:

"These new results from the Tata Project are extremely encouraging, with a substantial target area remaining unexplored. The sedimentary-hosted copper potential on this project is highly significant and demonstrates the scale opportunity in Morocco. We have created a strong asset portfolio in Morocco and are seeing positive results from our fieldwork on several projects. At Aterian, we firmly believe that projects like Tata have the potential to deliver tremendous value to the Company, its shareholders and other stakeholders. They also allow us to potentially supply the metals and minerals critical for a switch to the electrification of society. We will continue exploring and evaluating the Tata Project and other key assets within our portfolio. I look forward to updating shareholders on the Tata Project and the other exploration programmes in due course. We have created a strong asset portfolio in Morocco and are seeing positive results from our fieldwork on several projects."

Project Summary:

The Tata Project covers 154.4 km2 and comprises ten license blocks, with access to the Project via asphalt roads and a network of smaller tracks. The Company holds a 100 % interest in the Project, located in the western Anti-Atlas Mountains, a region considered highly prospective for sedimentary-hosted copper mineralisation. Tata lies 30 km south of the Company's Azrar copper-silver project, approximately 465 km south of the capital Rabat, 165 km southeast of the port city of Agadir, and 50 km southeast of the Tizert copper-silver project (estimated resources of 57 Mt grading 1.03 % Cu and 23 g/t Ag), currently under development by Managem Group. Late Ediacaran to early Cambrian-aged Adoudounian sediments occur within the Project along the margins of the Paleoproterozoic Tagragra de Tata Inlier. These sedimentary units are known to host copper mineralisation and represent the primary copper target on the Project.

Earlier prospecting by the Company along the northern part of the Tata Project identified visible copper mineralisation hosted within late Ediacaran to early Cambrian age Adoudounian sediments and also higher in the stratigraphy within the lower limestone and dolomitic units of the younger Tata Group. The sediments occur along the flanks of the Paleoproterozoic Tagragra de Tata Inlier, with the previous work traversing along a strike length of c. 8 km, where copper mineralisation was observed in outcrop. Previously reported highlights from the earlier phase of work are:

· 2.05 % Cu was reported from a dolomite float sample adjacent to the contact between Adoudounian sediments and the Proterozoic inlier.

· Results include 0.95 % Cu from a 4 m thick dolomitic sequence and 0.87% Cu from an 8 m thick sequence of dolomite and marl.

Aterian Exploration Results

The more recent fieldwork, with results reported today, concentrated on evaluating the sedimentary-hosted copper potential along a further 8.5 km of strike within the sedimentary package occurring on the northern margin of the Tagragra de Tata Inlier and an additional 2.0 km along the southern margin of the same inlier (Blocks A, B, C and D on the map below).

A total of 34 outcrop rock chip samples* were collected during this reported sampling campaign. Of these samples, 14 (41 % of this batch) were > 0.3 % Cu, with three samples returning values greater than 1 % Cu.

The maximum sample grade reported was 7.02 % Cu from bedding parallel, disseminated mineralisation occurring in siltstones within the lower Adoudou Formation (Block A). 250 m along strike to the east of this sample, an outcrop of fractured dolomite with mm-scale quartz-carbonate veinlets hosting disseminated copper oxides reported 1.62 % Cu.

The area prospected in Block A covers a strike length of 1.5 km; in Block B, the distance covered is c. 7.0 km, with Block B targeting copper mineralisation hosted with the lower Cambrian Tata Group sediments. Copper values returned from Block B range from 0.08 % Cu to 1.09 % Cu, with an average grade from 17 outcrop samples of 0.37 % Cu. The sediments north of the inlier dip 25o - 45o NNE to NE.

Blocks C and D cover a combined distance of 2.0 km and targeted Tata Group sediments, with the highest grade of 0.45 % Cu reported from 7 samples collected. Locally, these units appear more folded than to the north of the inlier, with the overall dip direction to the south.

Based on the field observations, with copper mineralisation occurring in two separate horizons within the overall sedimentary package, there remain c.26 km of strike length within the Adoudou Formation to be prospected, with at least 9.5 km of lower Cambrian Tata Group to be explored further (green dashed line on the map above). The work completed to date has identified copper occurring along 16 km of strike, hosted in both the Adoudou Formation and Tata Group to the north of the inlier and 2.5 km of strike within the Tata Group to the south of the inlier (red dashed line on the map above).

*A rock chip or grab sample cannot be taken as a representation of the overage grade average and potential deposit size. A float sample is collected from loose pieces of rock not connected to an outcrop.

Sampling Methodology and Analysis

ALS Limited, an accredited laboratory in Sevilla, Spain, undertook all sample preparation and analysis for these reported samples. Given the early-stage nature of these programmes, no QA/QC samples were included. Rock samples were crushed to 70 % passing -2 mm. The less than 2 mm fraction was pulverised, with 85 % of the sample passing were analysed for their gold content by a 50g Fire Assay method with an atomic absorption finish.

Work Plan for the Tata Project

Future work programmes at the Tata Project will include further geological mapping to explore the copper potential in the untested areas of the sedimentary package, supported by detailed mapping and channel samples at selected locations perpendicular to the bedding.

Illustrations The following figures have been prepared by Aterian and relate to the disclosures in this announcement.

Qualified Person

The technical disclosure in this regulatory announcement has been approved by Simon Rollason, Chief Executive Officer of Aterian Plc. A graduate of the University of the Witwatersrand in Geology (Hons). He is a Member of the Institute of Materials, Minerals and Mining, with over 30 years of experience in mineral exploration and mining.

- ENDS -

This announcement contains information which, prior to its disclosure, was inside information as stipulated under Regulation 11 of the Market Abuse (Amendment) (EU Exit) Regulations 2019/310 (as amended).

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 Broker:

Novum Securities Limited

David Coffman / George Duxberry

Tel: +44 (0)207 399 9400

Financial PR:

Bald Voodoo - ben@baldvoodoo.com

Ben KilbeyTel: +44 (0)7811 209 344

Notes to Editors:

About Aterian plc

www.aterianplc.com

Aterian plc is an LSE-listed exploration and development company with a diversified African portfolio of critical and strategic metals/minerals projects.

Aterian plc is actively seeking to acquire and develop new critical and strategic metal resources to strengthen its existing asset base whilst supporting ethical and sustainable supply chains as the world transitions to a sustainable, renewable future. The supply of these metals is vital for the development of the renewable energy, automotive and electronic manufacturing sectors that are playing an increasing role in reducing carbon emissions and meeting climate ambitions globally.

The Company recently entered into a joint venture agreement with Rio Tinto Mining and Exploration Limited for Rio Tinto to earn into the HCK project in southern Rwanda and holds two further partnerships in Rwanda exploring and developing lithium-tantalum-niobium-tin mining operations. Aterian currently holds a portfolio of 17 copper-silver and base metal projects with a project area of 897 km2 in the Kingdom of Morocco.

The Company's strategy is to seek new exploration and production opportunities across the African continent and to develop new sources of strategic and critical mineral assets for exploration, development, and trading.

Glossary of Terms

The following is a glossary of technical terms: