$?Bill in a ? Life mine, page-18996

@glemon, I concur with CE's comment that the anomalous Ag results are "interesting", and does warrant follow up, but IMO should be put on hold with the current focus to remain on completing the MRE's and PFS at this point in time.

Reason being within porphyry systems economic Ag is generally associated with either the epithermal region (Au-Ag) or the deep potassic-propylitic regions that generally correlates with elevated Cu, Mo, Zn, Pb. Intense hypogene leaching, due to injection of hot saline brine, in the potassic zone destroys host (±amphibole, ±pyroxene and ±feldspar) mineralogy, which has to occur to make space for base metal ore endowment. Moving upward within a porphyry through the mesothermal and epithermal zones there is increasing acidity and decreasing temperature (500°C --> 100°C) of the hydrothermal fluids. Increased acidity destroys feldspar and generates mica and illite and based on the feldspar type either Ca+, Na+, and/or K+ and silica until either the acid fluids run out or the hydrothermal fluid buffers with surficial meteoric waters, over the 4~6km vertical extent. Hence there is much variation in alteration mineralogy and geometallurgy within and lateral to porphyry system. In idealised economic systems the epithermal zone are generally Au rich, the mesothermal Au-Ag rich, whilst the porphyry is base metal ±Ag rich - but this depends on the metals that can be leached and redistributed from host rocks by hydrothermal convection, as well as metallogenic content of magmatic fluids or what these can strip from deep igneous host. Essentially rising hydrothermal fluids above porphyry centres continually produce sulfuric acid, due to SO2 disproportionation reaction, which leaches Zn, Mn, Cu, Pb, Ag, Co and Ni but precipitates Mo, Sn, W, Bi, Te, As, Sb in oxide, sulphide and silicate minerals.

Generally there is a zonation of trace metals, that is elevated above background values, upwards and lateral to the Cu zones in porphyry systems roughly in the sequence Mo, W, Sn, Se, Te, Bi, Sb, As, Li and Tl, which is why some have been posted by HCH previously. Note that most of these trace metals are in the ppm range, so not economic, but useful as geochemical vectors towards a potential potassic (hopefully with economic Cu-Mo-Au) zone. There are also variations between porphyry systems, e.g. the sericitic zones of silcia-rich magmas are relatively enriched in As, W, Sn, Cs, Sb and Zn, whereas alkaline / high-K magmas are relatively enriched in Te, Se, and Bi, so the type of porphyry will affect geochemical vectoring. Subsequently spectral vectoring, based on mica and chlorite + other mineralogy, can be complimentary or a better pathfinder, although I'm unsure if HCH are running an ASD halo or similar spectrometer over all their drillcore but I suspect they should / are.

So to have intersected Ag without Cu or Au is "interesting", and may have resulted from late-stage hypogene leaching of the potassic Cu ore zone that has preferentially re-distributed Ag to either the upper epithermal zone, or to the outer edge of the sericitic regions possibly as a hydrothermal skarn, where boiling / acidity of the hydrothermal fluids terminated. If this is correct then drilling possibly didn't intersect the primary potassic (Cu) host, and follow up is not as simple as just drill deeper, but may in fact be offset / lateral to current drillholes. Note this is without me knowing the structural history (i.e. has there been uplift, tilt or rotation of blocks) within the region and level of weathering and erosion in relation to the current porphyries. Exploration is not easy, despite much of the whaling by many here and on the interweb.

* note that I haven't see the drillcore, and/or any models of the geochemistry and mineralogy (preferably spectral over logging), so my response is merely academic in nature.