- Calibre discovered a small (300m x 200) moderately mineralised Cu-Au porphyry system
- It has been well explored with no good potential to expand
- In general, it is too small and too low grade to be explored further, hence the lack of recent news..
The Primavera gold-copper porphyry project is located 7 kilometers south of the historic Santa Rita copper-gold skarn mine. It is being JV by B2 Gold, and there a flurry of news releases in 2011 to 2013 but there have been no news since then, why?
When you look at the data you can quickly see that drilling has defined a small, medium grade (>0.2 g/t Au) core that is surrounded by a low grade (>0.05 g/t Au) mineralisation. From the hole locations and their traces, the high grade zone is very well explored and its limits are very well defined.
|Black lines = possible faults; yellow outlined = approx. area of >0.25 g/r Au mineralisation.
The description of the mineralisation by Calibre - “mineralization consists of millimeter to centimeter scale quartz-pyrite-chalcopyrite-bornite-magnetite veins associated with potassic alteration”. the presence of bornite and potassic alteration indicates that Calibre have drilled out the core, normally where the best grades are found, of a small porphyry system.
|Sulphide zonation if a big porphyry system - note the bornite in the core
I'm surprised that no resource calculation was completed for Primavera, but I'm guessing that Calibre/B2 knew that it was too small and too low grade to take it any further.
If you want to have a look at the data, you can find the leapfrog views here (link).