Mount Isa Lead, Zinc and Silver Mine - Mining Technology ...
Over 20 ore zones are mineable, each up to 1.4km long by 800m deep and from 4m to 48m wide. As of mid-2005, Xstrata reported that the underground Isa lead mine had proven reserves of 0.4Mt grading 5.9% zinc, 4.7% lead and 140g/t silver, and measured resources of 1Mt at approximately 7.3% Zn, 6.3% Pb and 180g/t Ag.