RE:RE:RE:RE:RE:RE:RE:Geologist discussing drill results Table 1-1 in the Jose-Maria technical report (SRK Consulting, 2020) shows a measured resource estimate of 197 million tonnes at an average 0.43% Cu grade and an indicated resource estimate of 962 million tonnes at an average 0.26% Cu grade, using a cut-off of 0.1% CuEq. The low cut-off grade is how they propose to run 19 years of production with a 150 ktpd mill.
Table 22-3 presents their production schedule summary of recovered grades Cu (%), Au (g/t), and Ag (g/t) for each year of production as follows:
Cu Au Ag
0.337 0.259 0.728
0.347 0.217 0.831
0.333 0.187 0.955
0.221 0.152 0.497
0.291 0.198 0.743
0.258 0.148 0.613
0.282 0.149 0.733
0.290 0.135 0.759
0.199 0.103 0.516
0.186 0.102 0.500
0.262 0.119 0.612
0.247 0.122 0.590
0.219 0.102 0.558
0.303 0.126 0.737
0.256 0.107 0.681
0.237 0.086 0.786
0.232 0.101 0.840
0.187 0.077 0.667
0.129 0.060 0.464
Thornton’s Santo Tomas North Zone analysis calculated 280.5 million tonnes of ore at an average grade of 0.441% Cu using a cut-off of 0.35% (Figure 15 in the ST technical report). He didn’t have the benefit of Au, Ag, and Mo assay data from the current drilling campaign. I estimate that contributions from those additional metals will give CuEq a lift of around 10%.
Much of the known North Zone resource is at near surface, which is favorable to extraction costs (lower). We are seeing additional areas outside the historical grade shell where tonnes will be added (from west of the grade shell and from Brasilles) that Thornton didn’t have the benefit of drilling data.
Argentina has a different business climate and hyperinflation, which are additional factors that may have played a role in the sale price of Jose-Maria.