Gold mineralisation at Blackwater is hosted in narrow quartz veins. Most of the gold-bearing quartz veins in the Reefton Goldfield are arranged along a linear belt that runs north-south through the Greenland Group sequence. This suggests the presence of a deep-seated structure that has tapped a large reservoir of mineralised fluid. All the gold production from the Blackwater Mine came from the Birthday Reef, a single quartz vein that was mined continuously for over 1,000m in strike and over 710m in depth.
A JORC compliant Mineral Resource has been calculated by Federation Mining following a significant drilling program in 2023 which built on knowledge from deep drilling completed by OceanaGold.