Oroco’s news release this past week was a nice early valentine’s day gift. In going through the reported data, I have a few observations.
The average CuEq lift to co-metals in the south zone is 16%. This is quite a bit more than what I had originally ball-parked prior to the drilling campaign, based on a review of a numerous copper projects in the Americas.
Areas with exceptionally high chargeability on the order of 40-50 mV/V, don’t necessarily deliver high copper. Those areas might be indicative of an iron-rich mineral or something else rather than copper mineralization. Data from the aero-magnetics survey might shed some light on this.
Thornton’s 2011 resource estimate did not assign significant value to the bulk of the south zone. There just wasn’t a sufficient amount of drilling and assay data to work with at the time. We can now see that the south zone resource is much greater.
In my analysis of the 3D-IP data, historical drill holes STD-36 and STD-50 caught my attention (see post on 2/8/21). STD-36 spanned some 232 meters of 0.40% - 0.54% Cu, while STD-50 spanned 275 meters of 0.42% - 0.49% Cu ore. The average range of these two measured ore zones is 253 meters.
The new dataset this past week reports that hole S018 returned 187.9 m of 0.58% CuEq and 234.3 m of 0.40% CuEq,besting the historical south zone data. S018 is south of the STD-36 and STD-50 location. You can see from the 3D viewer on Oroco’s website that there is some fair distance between those two historical measured resource holes and S018. This is good news because one can reasonably link these two profound depths of copper mineralization into a larger body.
You can see from the 3D viewer on Oroco’s website and the reported table data that the south zone resource is at surface. This means negligible strip ratio, higher grade in the early years of the mine life, greater cash flow, and a higher NPV. This is very good news.
As one continues further south, we have historical drill hole STE-53. Table 8 in the ST Report, “Listing of Significant Cu Composite Intervals,” states that it delivered some 32 m of 0.41 / 0.42% Cu. Adjusting for co-metals, this is likely 0.48% CuEq. STD-36 and STE-53 span a significant distance of 684 m. So there is quite some dimension to this ore deposit. It’s unclear to me if STE-53 is at the southernmost limit.
Assay results from drill holes S019 through S021 are pending. Looking forward to the data. I am also curious to know if the airborne gamma-ray spectrometry survey results, when overlaid with the recent positive assay results shows a correlation.
Cheers.