Exploration and Resource growth at the Buriticá Gold Project, Colombia
Provinces and Case Studies
The Buriticá Gold Project, owned by Continental Gold Inc. (TSX:CNL.TO; OTCQX:CGOOF), is located in the middle Cauca belt of Colombia, South America. Mineralization is a porphyry-related, carbonate base metal (CBM) gold vein/breccia system. Gold has been mined semi-continuously in the Buriticá area since prior to the arrival of Spanish colonialists. The Buriticá deposits Yaraguá and Veta Sur contain more than 9 moz with drilling underway and a resource upgrade scheduled for 2019. A 3,000tpd plant is under construction and production scheduled for early 2020 anticipates around 250,000-300,000 oz pa.
Mineralization at Buriticá is related to two main depositional stages. Stage 0: porphyry gold mineralization (gold, pyrite, pyrrhotite, quartz, K-feldspar) overprinted by Stage I: banded base-metal (iron, zinc and lead) sulphide-rich veins with quartz-carbonate gangue and Stage II: texturally and chemically distinctive gold-bearing (commonly visible and free) veins and breccia textures with siliceous and carbonate gangue, associated with arsenical pyrite and with low zinc and lead contents.
The Yaraguá system has been defined by drilling along 1,200 metres strike, 1,800 vertical metres and partially sampled underground developments. The Veta Sur system has been drilled along 1200 metres strike and 1,300 vertical metres. Both systems are characterised by sheeted multiple, steeply-dipping individual veins averaging 1.1m diluted width and a Broader Mineralized Zones that shows significant exploration upside, open along depth and strike. High-grade ore shoots are controlled by intersections of two or more veins and intrusive-hydrothermal breccias also act as feeders for Au-Ag mineralisation. The resource model currently contains over 90 individual veins built from 10,409 vein intercepts in drill holes and channel samples.
Successful exploration and resource development resulted in substantial growth in gold resources at Buriticá from 3.2 moz in 2011 to 8.98 moz in 2015 across all resource categories. CNL is strongly focused on exploration and resource-reserve expansion with aggressive greenfield, brownfield and infill drill programs.