Ann: Two Exceptional New Copper Discoveries at Storm, page-166

Gravity Anomalies:

Chalcocite at 1% in limestone adds 0.05 to the density of the rock. The deeper sedimentary horizon is only max 30m thick at a 330m depth which would increase the apparent density at surface by 0.005 (attenuated by a factor of roughly 10 due to depth). I don't think would be detectible above density variations in the host rocks.

A more plausible explanation for the gravity anomalies is the density difference between limestone (calcium carbonate) density 2.71 and dolomite (Calcuim Magnesium Cqarbonate) density 2.84 is 0.13, a much higher density density contrast than the chalcocite provides. There is much more dolomite and limestone around, so changing host rock type is probably the source of the gravity anomaly.

It would be funny if the gravity anomalies just gave them the guts to drill deeper and away from the outcropping copper, but had nothing to do with the copper. This happens a lot and some notable discoveries have been made this way (by drilling a false anomaly and getting lucky). The Ridgeway porphyry, one of the highest grade porphyrys found, was discovered by drilling a magnetic anomaly and subsequently drilling an IP anomaly, neither of which had much to do with the actual deposit which is non magnetic and has no IP response, but the false anomalies provided enough encouragement to do some drilling.

It's quite possible that the sedimentary copper deposit is going to be bigger than management think and the highest grades might not be in the gravity anomalies.