Summary

Mine Type	Underground
Study Completed	Prefeasibility
Stage	Construction
Commodities	Gold Silver
Mining Method	Longhole open stoping
Backfill type	...
Project Timeline	...
Mine Life	...
Snapshot	The Marmato Lower Mine project, initiated in 2023, is designed to access the broader porphyry mineralization beneath the Upper Mine. Lower Mine will include the construction of a second decline access, mine workings, CIP plant, dry stack tailings, and a project camp. In Q1 2025, the Aris initiated engineering assessments to expand the capacity of the CIP processing facility currently under construction. The upgraded 5,000 tpd design is planned to use the major components of the current 4,000 tpd design while integrating select higher-capacity components and additional equipment to achieve the increased capacity. As of May 07, 2025, the Marmato Lower Mine construction is progressing well, with updated plant capacity 5,000 tpd: -decline development underway with 323 metres completed to April 2025; -earthworks completed for the main substation platform, and continued earthworks for the process plant platform; -continued arrival of equipment and materials on site.

Deposit type

• Mesothermal
• Vein / narrow vein
• Epithermal
• Porphyry

Summary:

Deposit types
Marmato is interpreted to be a porphyry hosted gold deposit with shallow epithermal and deeper mesothermal features and this interpretation has informed the exploration and mining plans.

Aris Mining the announced discovery of a deep mineralization trend, now referred to as the Lower Mine, 300 metres below the then known resources in the Upper Mine.

The Lower Mine is characterized by structurally localized veinlets of quartz, pyrrhotite, chalcopyrite, bismuth minerals, and free gold associated with illite-smectite and kaolinite alteration of the host rock. A transition zone approximately 200 m in vertical extent exists between the Upper Mine and Lower Mine mineralization, and is characterized by the extension of Upper Mine epithermal veins into the mesothermal style Lower Mine mineralization. These features indicate a reduced intrusion environment.

Mineralization
Marmato mainly comprises northwest and west-northwest trending veins and veinlets, with intermediate sulfidation epithermal and mesothermal mineralization styles transitioning with depth from the Upper to the Lower Mines. The veins outcrop at the surface, and within Aris Mining’s mining titles, mineralization extends vertically over 1,100 m and remains open at depth and along strike, and has a high expansion potential from future underground drilling programs.

The Lower Mine mineralization is characterized by mesothermal fine veinlet (less than 5 cm thick) mineralization including quartz, pyrrhotite, chalcopyrite, bismuth sulfide, tellurides, and free gold, hosted primarily within the P1 porphyry unit. The steeply dipping, northwest trending veins are typically rimmed by a thin sodium-calcic alteration halo and the porphyry shows weak argillic and potassic alteration. The Lower Mine mineralization interpretation for the mineral resource estimate has been undertaken using a grade indicator approach to create low grade and high grade domains. The currently defined Lower Mine mineralization covers an area of 950 m northwest-southeast x 350 m northeast-southwest, over a vertical extent of 750 m.

Mining Methods

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Comminution

Crushers and Mills

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Processing

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Commodity Production

Operational metrics

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Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		Jun 30, 2022
.......................	.......................		Jun 30, 2025
.......................	.......................		Jun 30, 2025
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.......................	.......................		Jun 30, 2025