Site visit to La Higuera IOCG Cu-Au project in Chile

The Chilean coastal belt hosts a number of iron-oxide-copper-gold (IOCG) projects of significant size (Candelaria, Mantoverde, Mina Justa, among others) that confirm the prospectivity and economic viability for deposits within the Cretaceous-aged north-south trending structurally controlled (Atacama Fault Zone) belt for further exploration.

The infrastructure available (desalinized water, power, roads, railway, and access to ports) at a low elevation makes the capital intensity and operating costs of building an IOCG project within the Atacama Fault Zone (AFZ) less intense than that of advancing a similar project in the high Andes (>4,000 masl).

I have an affinity for IOCG deposits as I did my first Master's in Geology and Mining and James Cook University on this style of copper-gold mineralization in the Mount Isa Inlier of central Queensland. In addition, I worked in the area on IOCG-style deposits further north with an Australian miner, North Limited (de-listed after being acquired by Rio Tinto). I also worked on a copper-gold skarn east of La Serena and actually met a fellow, that worked with me on the project 25 years ago, on my tour of La Higuera.

The CEO of Tribeca Resources , Paul Gow , did his Ph.D. around a well-known and large IOCG mine (the giant Olympic Dam) in South Australia and has worked in the Mount Isa and Carajás IOCG districts, therefore, bringing a lot of expertise to the company for this deposit style.

The micro-cap junior copper explorer raised C$2.6 million in early 2022, which I participated in, after consolidating 4 projects that cover the La Higuera IOCG project with a drill focus on the Gaby and Chirsposo prospects. The company is working on trying to fill in some holes within the land package as not all the magnetic anomalies are fully covered.

The majority of the property is under a thin layer of unconsolidated alluvium therefore geophysical methods such as magnetics and gravity help locate the centers of alteration but the induced polarization surveys that delineate chargeability anomalies point (hopefully) to the zones of copper-gold mineralization which tend to sit on the sides of the gravity/magnetic anomalies.

The best results from the Phase 1 drill program (2,800 m) focused predominantly on the >1 km north-south trending IOCG-related copper-gold mineralization at the Gaby prospect and less so at Chirposo.

The mineralization at Gaby appears to be controlled by a north-south trending structure parallel to the main AFZ as outside the structure the grade of the mineralization falls but is still anomalous (0.2-0.3% Cu with 0.05-0.07 g/t Au) in smaller intervals (14 m).

But there is more to the structural and potentially the lithological controls on the IOCG-style copper-gold mineralization as the company failed to follow up on historic results (285 m grading 0.4% Cu and 0.08 g/t Au) with a pair of holes (GBY004 and -005).

A quick review of the core indicates that the host rock is an andesite porphyry at Gaby. The high-grade zones (>20% Cu and 7 g/t Au) of massive chalcopyrite with pyrite and some pyrrhotite are flanked by lower-grade (0.3% Cu) stockwork zones of scapolite (Ca4Al6Si6O24CO3).

In order to earn-in 100% of the ownership of the properties, Tribeca Resources must make a final payment of US$2 million to the underlying owners by March 2024.

Its planned Phase 2 program will follow up on the Phase 1 program that has delineated a potential zone with a 1.0 km north-south strike with a thickness of 50 to 130 meters that can be found to a depth of 250 meters, which is open to the north and to depth. The Gaby prospect alone suggests a potential tonnage of anywhere from 40 to 100 million tonnes but obviously needs to be confirmed with more drilling.

In addition, there are other prospects to test thoroughly and consolidation of the geophysical trends (magnetic, gravity, IP) would also be a major catalyst.

[I own shares of Tribeca Resources.]