Previous mining at Porphyry occurred in the 1980s. This included an underground operation where a room and pillar mining method was employed to extract the relatively shallow dipping near-surface extension of the lode that was previously exploited through surface mining. All underground decline development was in ore, resulting in very low capital costs. Mining was abandoned in the late 1980s due to poor margins at a lower gold price.
A similar method could be employed to further exploit the deposit down dip and plunge, whilst minimising capital start up costs.
