Olympic Dam drill core.   Following the presentation session, interested members of the group were given a 40 minute tour of the Olympic Dam operation, before re-joining the remainder that had gone direct to the core yard. The rest of the day was spent in the vast core yard where Kathy Ehrig (left image) guided the group through a series of drill holes illustrating the transition from hematitic brecciated Roxby Downs Granite on the outer margins of the Olympic Dam Breccia Complex, through various stages of hematitic mono- and polylithic (granite, sedimentary and mafic volcanic/dyke rock bearing) breccias, with a variety of pre- and post mineralisation mafic dykes, and zones of volcaniclastic rocks in the upper parts of the complex, to massive hematite-quartz breccia in the upper core of the deposit, to pyrite-bearing magnetite at depth in the lower sections of the mineralised system. The core session was punctuated by lunch in the air-condioned office, affording a break from the +40°C of the core yard, and ended in mid-afternoon at the end of the working day at the mine. The group then returned to their motel for a series of presentations by tour members, where they were joined by BHP Billiton geological staff. This was followed by dinner in the courtyard and more discussion prompted by what had been seen that day.   Photographs by Mike Porter.