SRK assisted a private equity client with a Mineral Resource Estimation on cobalt-copper mesothermal vein systems at the Rosa Amelia Mine Area within the La Cobaltera District, Chile.
The La Cobaltera mining district is comprised of cobalt (Co) and copper (Cu) vein systems along multiple exploration trends and is one of the few primary Co districts known globally. With artisanal mining activity from the 1840s to mid-1900s, significant small-scale historical production occurred in the district at grades averaging >6% Co and >2% Cu. After locating and deciphering a ‘treasure trove’ of historical documents, including geological records, tattered maps, and past mining production accounts, fieldwork began in 2018 and included geochemical surface sampling, airborne geophysical survey, mineralogical studies, and geological mapping. Chilean Cobalt Corporation initially targeted the Co-rich vein systems near the historical Rosa Amelia Mine with 68 drillholes totaling over 14,000 meters.
SRK carried out a comprehensive scope of work, as summarized below:
- Performed multiple field visits for verification and audits of supporting data;
- Reviewed and validated the drilling database, geological logging, sampling procedures, laboratory analytical results, and QA/QC protocols and results;
- Exploratory data analysis of domained analytical data (e.g. capping, compositing);
- Created 3D models for geological, geometallurgical, and estimation domains;
- Developed a block model with estimated resources for economic variables and validated the model and supporting assumptions, such as density measurements;
- Classified the resources to reflect the relative confidence of the geological interpretation and modeling, analytical data quality, grade estimates, and mineralization continuity;
- Reviewed metallurgical data to derive metal recovery estimates; and
- Evaluated open-pit and underground optimization and other modifying factors to determine “reasonable prospects for eventual economic extraction” and commented on cutoff grade assumptions and variability.
The project culminated in a Technical Report on Mineral Resources following the Canadian National Instrument 43-101 disclosure format. While the Client is a private company and not subject to securities legislation in a particular jurisdiction, reporting in agreement with international codes was important to providing confidence in the work, which resulted in a CIM-compliant resource.
SRK estimated Mineral Resources within the Rosa Amelia Mine area cobalt-rich vein system, a combined 2.5-kilometer drill-defined strike length trend that represents less than 10 percent of the vein potential identified from surface mapping within the La Cobaltera District. Further drill-definition is pending for these other prospective exploration areas and the Client is focusing on drilling high-priority targets for possible resource expansion.
