Mallama and Guachaves, Nariño Department, Colombia


100% owned

Deposit Type

Intermediate sulfidation, epithermal

Primary Minerals

Gold and Silver


Advanced Exploration


The Mallama project comprises 9,036 ha of titles located in Nariño Department. It is 56 km in a direct line form San Juan de Pasto, the capital of Nariño and 126 km by paved roads, unimproved roads, and trails to access the interior of the project.

The Mallama titles are trimmed to conform to an elevation well below the Paramo with its environmental restrictions. The property covers a large portion of the Piedrancha district and hosts more than thirty-five mapped and projected epithermal veins that have strike lengths of up to 5 km. Piedrancha is known for being one of the largest and most important epithermal districts in Colombia.


Historical records suggest that gold production from artisanal mining activities started in post colonial times during the XIX century. At least eight artisanal mines are active in the property, producing gold and some silver from high-grade veins in the Bombona zone. Extensive exploration efforts were conducted in the 1980´s by JICA and recent sampling conducted by Outcrop in the Bombona zone shows gold grades that exceed 15g Au/t.


Mallama is situated within a well-endowed mineral and tectonic belt that hosts Cascabel and La Colosa which are the largest discoveries in Ecuador and Colombia respectively. Outcrop believes significant mineralization and shoots will be identified by exploring and delineating the extensions of current artisan mine workings down dip and to surface and along the entire three to four-kilometer strike of the vein zones.

The extensive distribution of veins and active workings in a district the size of Piedrancha indicates that Mallama has excellent potential. Piedrancha is an established vein district and that essentially a “discovery” has already been made by artisan miners.


Mapping and sampling within the Mallama project show a prevalence of high-angle, high-grade gold and silver veins that occur in groups of eight or more veins averaging 1.0 m width. 

Systematic sampling demonstrates that in situ mining grades in the largest accessible working of the Bombona zone show a weighted average grade of 23.3 g Au/t and 182 g Ag/t with a mean grade of 22 g Au/t. Production portals suggest four or more veins are under development in the central Bombona zone. Additional active mines occur to the northwest and southeast along 4 km of veins.

Outcrop has taken a total of forty-seven channel samples in the course of its work in Bombona zone workings. One-third of all samples taken exceed 15g Au/t. 

The JICA data shows that the known veins can be traced well with soil sampling. The soil sample anomalies indicate that numerous veins are unexposed near existing workings. Outcrop has concentrated in the Bombona Zone where historic workings are extensive and currently in operation by artisanal miners. 

Community and Stakeholder Relations

Mallama includes lands recognized as traditional homelands of indigenous peoples. This requires a consultation called Consulta Previa with the indigenous communities. This process is underway, and Outcrop has done baseline work to study cultural and social aspects of the community in order to build respectful, effective, supportive and mutual benefiting relationships with the community.

Informal mining has been conducted for decades in Mallama and Outcrop wants to accommodate and or incorporate artisan miners in modern exploration and any future mining activity.

Since acquisition, Outcrop maintains the title in good standing with the mining agency and has established good communication with leaders of the community to reach a public consultation.

Future Plans

Outcrop is initially focusing on a 1,200 ha portion of the 9,036 ha project to complete an environmental study to subtract the titles from Forestry Reserve. Outcrop has established communications with local authorities and conducts some low impact social work in the community to move the project towards exploration drilling stage.

Outcrop is actively seeking a funding joint venture partner for Mallama.

Project Maps and Photos

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12