Marimaca timing its run to meet resurgent demand for copper

Copper projects are in the spotlight amid growing forecast of a supply crunch for this base metal

Marimaca timing its run to meet resurgent demand for copper

Copper projects are in the spotlight amid growing forecasts

Of a severe supply crunch for the king of base metals. One of the projects currently in development is Marimaca Copper's Marimaca project in northern Chile, which president Hayden Locke says is uniquely positioned to meet resurgent demand for copper.

The company's flagship Marimaca oxide deposit Boasts a resource of 113 million tonnes in the Measured, Indicated and Inferred categories with an average grade of 0.6% total copper, according to a December 2019 mineral resource update, which saw a 100% increase over the maiden estimate from 2018.

Better yet, according to Locke, are the results of an August 2020 Preliminary Economic Assessment, which put the Marimaca project firmly in the lowest quartile of copper projects in terms of capital intensity and operating costs.

The PEA showed a pre-production capital cost of $285 million, or $7,125/tonne of copper production capacity, 46% below the industry weighted average and 23% below the threshold for the bottom quartile.

Other highlights of the PEA included a post-tax net present value of $524 million and post-tax internal rate of return of 33.5%. The company is targeting completion of a feasibility study and all permitting in 2022, which would put in on track to commence production in 2024.

"The vast majority of copper discoveries are very large scale and have high development capex and long lead development times. This project has a very low capital cost, very short development time, and very low execution risk from a financing perspective and from a construction and operational aspect," Locke says.

"The reason is that it's a simple open pit mine whereas a lot of new discoveries now are getting deeper and deeper underground at lower and lower grades, meaning they have to move more tonnes.


Marimaca is relatively high grade for a low strip open pit. It involves simple processing, so has a much lower capital intensity than a typical big sulphide copper project."

Another obvious benefit is the location in northern Chile, the highest-ranked Latin American jurisdiction in the Fraser Institute Annual Survey of Mining Companies 2020 and a country well-known for being by far the world's largest producer of copper.

Locke, who spent a large part of the last decade with junior companies in Africa - among other roles, he was CEO of Moroccan-focused potash developer Emmerson plc and had an executive role at West Africa-focused Papillon Resources before that company was bought by B2Gold - says having a project in Chile is "amazing".

Adding to the low jurisdictional risk is the fact that the project is situated in the low Andes, only about 1,000m above sea level, close to roads and powerlines, and within 60km of two port cities (Antofagasta and Mejillones) boasting large pools of skilled workers.

Marimaca also plans to take advantage of a seawater pipeline running 7km to the north of the deposit.

"That means we're not going to be tapping any freshwater aquifers that might be used for drinking. We're not going to risk polluting these aquifers by drilling down into them. This will eliminate one huge risk associated with mining in this part of the world."

Marimaca was discovered in 2016 and had the honour of being the only major greenfield copper discovery anywhere in the world between 2015 to 2019, according to S&P Global Market Intelligence. Despite this achievement, Locke says the Marimaca project's "only weakness" is its scale.

However he believes that there are more Marimaca-style discoveries to come, noting that Sergio Rivera - the former director of Codelco's exploration activities in Chile who made the Marimaca discovery and is now VP of exploration for Marimaca Copper - "thinks we're potentially on to a new copper district in Chile."

The Marimaca deposit is a new type of copper deposit in this part of northern Chile, and the breakthrough was made by challenging the consensus and generally accepted wisdom of the geological potential in the region, according to Locke.

He says his company has an amazing opportunity to apply the lessons learned from the Marimaca discovery to the surrounding area.

"Now we control this whole belt that's never been explored, and we intend to go out and drill the targets we have identified pretty aggressively," he says.


A recent drone-mounted high-resolution magnetic survey of Marimaca Copper's licence area identified five large-scale anomalies believed to be potential Marimaca-style deposits.

Follow-up work involving surface geochemical sampling and reconnaissance mapping at two of these targets - Cindy and Mercedes - delivered encouraging results. Geochemical sampling at Cindy identified a copper anomaly extending over 1km of strike with grades as high as 2.9% Cu. Sampling at Mercedes identified another large anomaly with grades as high as 0.6% Cu.

Marimaca Copper is fully financed to conduct the drilling campaign, thanks to the completion of a C$28.98 million ($23 million) equity financing in December 2020 and a follow-up placement of just over C$30 million to a strategic, long term, investor in February 2021.

Drill rigs were mobilised in January 2021, with the plan being to drill at the Cindy, Mercedes and Llanos anomalies and to test for extensions at depth at the Marimaca deposit, where there is copper sulphide potential below the already defined oxide deposit.

Locke says results from the Marimaca drilling campaign are expected by the end of Q1 and results from the three new targets are expected by the end of Q2.

Marimaca Copper



  • Hayden Locke

  • Michael Haworth

  • Tim Petterson

  • Clive Newall

  • Colin Kinley

  • Alan Stephens

  • Giancarlo Bruno Lagomarsino

QUOTED SHARES ON ISSUE (as of 2 April 2024):

  • 93,241,923 million


  • C$288 million


Greenstone 27.4%

Tembo 10.9%

Mitsubishi Corp. 5.0%

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