Overview of some Colombian gold deposits and their development potential

Source rock gold deposits in Colombia include Proterozoic unconformity-related paleoplacers, Palaeozoic stratabound Au/Ag-Cu-Pb-V-U red bed-type ores, and Mesozoic/Tertiary hydrothermal vein systems of Cordilleran magmatic arcs. The younger metallogenic episode occurred some 8 Ma ago in the Western Cordillera. Epithermal deposits are generally small (> 10,000–1 Mt grading 5–10 g/t Au) and the precious-base metal (Cu, Zn, Fe) association was probably deposited within the temperature range 180–300 °C. Widespread palaeoplacers in Quaternary terraces with enrichment in old channels, as well as extensively dredged alluvial deposits in presently active sediments, are connected with ongoing Andean uplift and erosion. Palaeochannel and alluvial gold concentrations represent the most promising targets for future exploration. An additional output could also derive from the clastic-hosted, stratiform deposits of the shield and E Cordillera.