MML - Q1 Production Report, page-3

With regard to deeper level resources, it would be very surprising if they did not continue to find more. As, by definition, epithermal vein systems are formed by deeply sourced rising super-heated minerals fluids heated by the mantle millions of years ago. So as long as later geological events have not radically shifted those veins they should be found at ever deeper levels.

As they are only at 350m so far it looks highly probable that there may be decades of mining to come from the Co-O vein system. But clearly, before committing to the future L16 shaft they must confirm the continuity of those veins down at least another 400m.
CPDLC