Location and History

soto norte mine location

The Soto Norte Gold Gold Project is located within the traditional mining area of California – Vetas, located approximately 350 km north of Bogota and 55 km northeast of the city of Bucaramanga, the capital of the Department of Santander.

In December 2005, Ventana Gold Corporation (“Ventana”), a TSX listed Canadian company, acquired various small-scale tenements from artisanal miners and formed the La Bodega exploration Project, and conducted surface exploration, diamond drilling, and a preliminary economic assessment of the La Bodega Project. In 2011, EBX Group, via AUX Canada, announced the successful acquisition of Ventana for US$1.4B, and changed the project name to El Gigante. AUX consolidated the adjacent Calvista Gold and Galway Resources properties in December 2012.

Mubadala Investment Company (“Mubadala”) took over ownership of AUX in February 2015 and renamed the company to Sociedad Minera de Santander S.A.S. (“Minesa”) and the project to Soto Norte. Since 2015, Minesa has undertaken extensive consultation and invested significant resources in engaging with the local communities in preparing an initial Environmental and Social Impact Assessment (ESIA). Following detailed technical feedback from the Colombian environmental regulatory authority (ANLA) in 2021, Minesa began drafting a new ESIA to include a robust Quality Assurance and Quality Control process for regulatory compliance.

In March 2022, Aris Mining became operator of the Soto Norte project and has prepared a NI43-101 Feasibility Study with an effective date of 1 January 2021 that was authored by SRK, SNC-Lavalin and Minesa.

Exploration and Mineral Resources & Reserves

The first modern exploration program on the Soto Norte Project (then known as the La Bodega Project) was undertaken by Ventana, commencing in December 2005. By 2019, 901 drillholes totalling nearly 375 km were drilled within mining concession 095-68, which identified two principal parallel mineralised structures (Mascota and El Gigante) with a strike length of 2.6 km that contain precious metals and sulphide minerals dominated by pyrite and, to a lesser extent, copper minerals.

The deposit hosts Probable mineral reserves of 24.8 Mt at 6.22 g/t Au, containing 5.0 Moz of gold, Indicated mineral resources of 48.1 Mt at 5.47 g/t Au containing 8.5 Moz of gold (inclusive of mineral reserves) and Inferred mineral resources of 27.3 Mt at 4.06 g/t Au, containing 3.6 Moz of gold, located in mining concession 095-68.

Exploration drilling from surface has not yet reached the bottom or the strike extents of Soto Norte, leaving the deposit open in all directions, and with high exploration potential to target the deep structures from underground drilling stations.

Soto Norte mine overview

“Exploration drilling from surface has not yet reached the bottom or the strike extents of the mineral deposit, leaving the deposit open at depth and along strike”

-- SRK (March 2022)

Mining & Processing

There will be two principal areas of operation on site, including Padilla and Emboque, which are separated by 13 km of road. Padilla is located near the municipality of Suratá and comprises the camp area, processing plant, dry filtered tailings facility, operation laydown, box cut, and main utility facilities. Emboque is the mine area, consisting of ventilation terraces, access roads, and tunnel access. A 6.9 km long access tunnel will be developed from the Padilla area to reach an underground mine in the Emboque area. Modified Avoca mining methods will be used to mine the ore, which will be crushed underground and conveyed to the surface process facility at Padilla at a rate of 2.6 Mtpa.

The ore will be processed at the plant facilities using a single stage semi-autogenous grinding mill followed by sequential flotation producing separate copper and pyrite concentrates. Due to the decision to produce concentrates, the operation will not require the use of any cyanide or mercury. Waste from the mine plan will be stored in a dry stack tailings storage facility (DSF), with the capability to store dry filtered tailings underground in waste quarry stopes to further minimize the surface footprint.

“All World Bank controlled environmental parameters are shown to be within the designated standards.” – SRK (March 2022)

Soto Norte Economic Highlights

A feasibility study on the Soto Norte Gold Project with an effective date of January 1, 2021 shows robust base case project economics with a post-tax NPV(5%) of $1.5B using a gold price of $1,675 per ounce.

The project is economically positive over a range of metal prices, as shown in the table below.

Gold price per ounce $1,425 $1,475 $1,525 $1,575 $1,625 $1,675 $1,725 $1,775 $1,825 $1,875 $1,925
After-tax net cashflow (undiscounted) USD B 2.0 2.2 2.3 2.5 2.6 2.8 2.9 3.1 3.2 3.3 3.5
After-tax NPV (5%) USD B 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0
After-tax IRR % 16.7 17.6 18.4 19.2 20.0 20.8 21.5 22.3 23.0 23.7 24.4

With feasibility work and initial front-end engineering complete, Aris Mining is in the process of developing an updated ESIA for submission to ANLA.


@ 6.2 g/t

Probable gold Reserves


@ 5.5 g/t

Indicated gold Resources1


@ 4.0 g/t

Inferred gold Resources

14 years


Mine Life



Processing capacity


Per year

LOM average gold production2



LOM average AISC



Initial capital

1. Indicated mineral resources are inclusive of reserves. Please refer to the Mineral resource and reserve tables for details.
2. over the steady state production years between years 5 and 13.