LWIR targeting for copper-gold porphyries under vegetation, Colombia.
Colombia is one of the world’s most prospective nations for porphyry copper-gold deposits, located at the under-explored northern end of the prolific Andean mineral belt. But unlike nations such as Chile, Argentina and
Peru, the Colombian Andes are heavily vegetated due to the country’s tropical climate. This makes geologic prospecting difficult due to a lack of surface exposure, and impedes traditional short wave satellite surveys for mineral exploration.
Long Wave Infrared (LWIR) satellite imagery was used to survey a 3,000 sq km area of vegetated terrain in
northern Colombia, which desktop studies had found to be prospective for copper-gold porphyries.
The LWIR analysis identified a 50 kilometer-long corridor within the area of interest showing response for chalcopyrite mineralization. N-Side then used imaging for common porphyry indicator minerals alunite and saponite (smectite clay) to narrow targeting to a discrete 10 kilometer target area.
A one-week field confirmation program discovered regionally extensive, previously unreported alunite and clay alteration within intrusive rocks permissive for porphyry mineralization. The project was then flagged for a second phase of fieldwork consisting of stream sediment sampling to vector into potential copper and gold mineralized zones within the alteration halo.