The Buriticá project is Continental Gold’s 100%-owned flagship high-grade gold project located in the middle Cauca belt in the northwest region of Colombia. Fully permitted and on schedule for 2020 production, the project is easily accessible by an approximately two-hour drive on the paved Pan-American highway from Medellín, Colombia’s second largest city. The Buriticá project is a rare combination of size, grade, straightforward metallurgy, excellent infrastructure and growth potential. On March 18, 2019, the Company released an independent technical report that indicates the Buriticá project will be a lowest quartile cost producer and an economically robust mine. Once in production, Buriticá has the potential to approximately double the formal production of gold in Colombia and become the largest single gold mine in the country.
In association with various government entities in Colombia, the Company was the first in the country to formalize small-scale mining associations, paving the way for the implementation of legal and responsible small-scale mining operations at the Buriticá project. In addition, the Company has operated a 30 tpd small-scale mine at Buriticá since 2007 and is one of the largest employers in northwestern Antioquia. The Company focuses on providing a safe working environment and partnering with local communities on key social projects.
On January 30, 2019, the Company issued an updated mineral resource estimate for the Buriticá Project (the “2019 Resource Estimate”) based on 356,053 metres of drilling and 9,294 metres of underground sampling (as at January 30, 2019) that included:
The Company subsequently filed on SEDAR a technical report (the “2019 Technical Report”) prepared by Ivor James Pty Ltd. in respect of the 2019 Resource Estimate entitled “NI 43‐101 Buriticá Mineral Resource 2019-01, Antioquia, Colombia” dated March 18, 2019 with an effective date of January 30, 2019.
The project’s Mineral Reserve estimate from the Feasibility Study is derived from the May 2015 Mineral Resource Estimate and covers both the Yaraguá and Veta Sur vein systems, and includes:
See Mineral Reserves & Resources for complete details.
The project’s Mineral Resource estimate, is based on 356,053 metres of drilling and 9,294 metres of underground sampling (as at January 26, 2019) and include:
See Mineral Reserves & Resources for complete details.
Within the Buriticá project, there are several exploration targets (within a 22 square kilometre-area of interest) that have been generated by geophysics and systematic soil geochemistry. The area of interest includes high-grade carbonate base metal gold vein deposits (“CBM”) feeding off of andesitic/microdioritic porphyries at depth. The combined mineral resources and combined mineral reserves estimates are derived solely from the Yaraguá and Veta Sur vein systems and both remain open along strike and at depth.
The Buriticá project is located in mountainous terrain with a peak elevation of approximately 2,000 metres above sea level. The focus area of the project is a mountain slope which is approximately 900 vertical metres in length and is adjacent to the flat-lying Higabra Valley, 1,000 metres above sea level.
The key support infrastructure includes the following:
Mineralization at Buriticá is a porphyry-related, carbonate base metal (CBM) gold vein/breccia system. High-grade precious metal mineralization in CBM systems may occur over substantial vertical intervals, to well in excess of one kilometre, from the porphyry level to below the shallow epithermal range. Compared to low-sulfidation epithermal styles, CBM mineralization is sulphide-rich, with abundant pyrite +/- pyrrhotite plus sphalerite and galena along with minor sulfosalts and chalcopyrite and with quartz-carbonate gangue mineralogy. Mineralization in CBM systems typically comprises sheeted veins, stockworks and mineralogically similar breccias with some fracture-related disseminations in wall-rocks.
CBM systems are widespread in circum-Pacific magmatic arcs and include the supergiant Peñasquito deposit (Goldcorp: >25 million ounces of gold) and the Porgera deposits in Papua New Guinea (Barrick/Zinjin Mining Group: >25 million ounces of gold, previous production plus remaining reserves and resources) and the Kelian deposits (7 million ounces of gold produced + resources) in Indonesia. Gold mineralization at Porgera has been mined over a vertical range of approximately 1,000 metres.
As at Porgera, precious metal mineralization in Yaraguá and Veta Sur appears to be related to two main depositional stages. “Stage I” is represented by banded base-metal (iron, zinc and lead) sulphide-rich mineralization with variable amounts of quartz-carbonate gangue and bands. “Stage II” mineralization is texturally and chemically distinctive high-grade gold mineralization that locally cross-cuts and overprints Stage I mineralization as veins and breccia veins. Stage II mineralization is characterized by abundant free (and commonly visible) gold in siliceous and carbonate gangue, associated with arsenical pyrite and with low zinc and lead contents.
The Buriticá Project comprises 80 tenements and applications covering an area of approximately 75,583 hectares. As in the case of all the Company’s properties, concession applications in process give the Company priority on the properties in question during the application process; however, there is no guarantee that the Company will be granted the pending concession applications.
The Company has operated a small maximum capacity 35 tpd small-scale operating mine at Buriticá for over 20 years and is one of the largest employers in north-western Antioquia, employing over 300 members of the local community. To date, over 10 kilometres of horizontal development has been completed in the Yaraguá vein system.
The small-scale operating mine has historically developed along individual veins in competent andesite rock. With over 10 kilometres of underground development, the Company has been able to perform underground channel sampling, cross-cutting and drilling. Results from this underground work have demonstrated the continuity of high grades over potential mining widths along substantial strike lengths and have resulted in grades that are generally higher than the drilling-based assay results in comparable regions of the current mineral resource model.
Donald Gray, BSc. Mining Engineering and MSc. Civil Engineering, Chief Operating Officer of the Company and a QP, has reviewed and approved the technical information above.
The Company utilizes a rigorous, industry-standard QA/QC program. For exploration and infill core drilling, the Company applied its standard protocols for sampling and assay. HQ and NQ core is sawn or split with one-half shipped to a sample preparation laboratory in Medellín run by ALS Colombia Limited (“ALS”), whereas BQ core samples are full core. Samples are then shipped for analysis to an ALS-certified assay laboratory in Lima, Peru. The remainder of the core is stored in a secured storage facility for future assay verification. Blanks, duplicates and certified reference standards are inserted into the sample stream to monitor laboratory performance and a portion of the samples are periodically check assayed at SGS Colombia S.A., a certified assay laboratory in Medellín, Colombia.