Marmato Lower Mine Expansion Project

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Mine TypeUnderground
  • Gold
  • Silver
Mining Method
  • Longhole open stoping
Backfill type ... Lock
Production Start... Lock
Mine Life... Lock
SnapshotMarmato Lower Mine Project Updates:
• On July 12, 2023, the Company received approval from Corpocaldas of the PMA which permits the development of the Marmato Lower Mine.
• Construction of the new underground mine will provide access to the wider porphyry mineralization below the current Upper Mine.
• Highlights of current construction activity include:
- initial environmental monitoring systems have been installed;
- the access road to the new processing facility area is now complete and earthworks in the plant area will commence soon.
- the contractor for the new portal and decline is fully mobilized and cutting of the portal face has commenced.
- the new 4,000 tpd mill and processing facility is on schedule for mechanical completion by the end of Q4 2025; and
- Ausenco has been appointed EPCM contractor for the processing plant.
Related AssetMarmato Upper Zone


Aris Mining Corp. 100 % Indirect
Marmato Project (Marmato Project) owned by Caldas Gold Marmato S.A.S. (CGM or the Company), an indirect, wholly-owned subsidiary of Aris Gold (Formerly Caldas Gold).

GCM Mining Corp. (Formerly Gran Colombia Gold Corp.) now owns approximately 44.3% of Aris Gold.

On September 26, 2022, GCM Mining Corp. and Aris Gold Corporation completed the business combination previously announced on July 25, 2022. The combined entity has been renamed Aris Mining Corporation.

At closing, GCM Mining was renamed Aris Mining Corporation and Aris Gold amalgamated with 1373945 B.C. Ltd. to form Aris Mining Holdings Corp. (Aris Holdings), which is now a wholly owned subsidiary of Aris Mining.



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Deposit type

  • Mesothermal
  • Vein / narrow vein
  • Epithermal
  • Porphyry


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.

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.



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Mining Methods


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Crushers and Mills


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Silver koz 1,543
All production numbers are expressed as metal in doré.

Operational metrics

Daily ore mining rate  ....  Subscribe
Daily processing capacity  ....  Subscribe
Annual ore mining rate  ....  Subscribe
Annual processing capacity  ....  Subscribe
Tonnes processed  ....  Subscribe
Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Total tonnes mined, LOM  ....  Subscribe
* According to 2022 study.

Production Costs

Cash costs Gold USD  ....  Subscribe
Assumed price Silver USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2022 study / presentation.

Operating Costs

UG mining costs ($/t milled) USD 41.1 *  
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2022 study.

Project Costs

MetricsUnitsLOM Total
Expansion CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
OP OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 389
G&A costs $M USD 199.2

Heavy Mobile Equipment


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Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jun 30, 2022
....................... Subscription required ....................... Subscription required Subscription required Jun 30, 2022
....................... Subscription required ....................... Subscription required Subscription required Jan 11, 2024
....................... Subscription required ....................... Subscription required Subscription required Jan 11, 2024

Total WorkforceYear
...... Subscription required 2020

Aerial view:


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