The Century Zn-Pb-Ag deposit, located about 250 km north-northwest of Mount Isa,Queensland,was discovered by CRA Exploration in 1990 following several years of regional area selection studies and initial reconnaissance field work.Post discovery drilling has outlined a resource containing 116 Mt of 10.3% zinc,1.5% lead,and 35×10^-6 silver.Geophysical techniques have been applied at Century since the discovery to help define the limits of mineralisation,map lithologic boundaries and structure,provide data for ore reserve estimates and mine planning,and to aid ongoing exploration in the area.Methods used have been gravity,ground and airborne magnetics,ground and airborne electromagnetics,IP/resistivity,downhole geophysical logging,and reflection seismic.The most useful technique to date has been IP/resistivity,which has assisted in mapping the extent of mineralisation beneath limestone and younger cover to depths of at least 150 m.