The Comstock deposit and minesite is located 5km to the west of the township of Zeehan. Comstock has a long history of mining, beginning in the 19th century, with early underground lode mining carried out along fault structures for high grade lead and silver ore.
In the late 1980’s, a small scale open cut mining operation was carried out over the South Lode and Allison’s Lode, yielding a total of 7000t of ore @ 14.8% Zn and 3.6% Pb.
With the existing gravity plant, tailings dam and other infrastructure, the Comstock mine site will become a processing hub for both iron ore and base metal ore processing. Ore from Tenth Legion and Oceana deposits will be trucked for short distances to Comstock, while the Boss lead-zinc deposit is located adjacent to the processing site. All products will be stockpiled at the Comstock site and then transported by truck, either to railway loading facility at Melba Flats near Zeehan, or to the Burnie Port directly.
The crushing, milling and magnetic separation circuit for Tenth Legion magnetite mining will be constructed at Comstock. This new facility and existing gravity plant will be both available for lead-zinc-silver ore processing after iron ore mining is finished.
Between 2017 and 2018, AHL drilled a total of 29 infill diamond holes over the Boss deposit at Comstock. Hellman & Schofield Pty. Ltd. completed a JORC 2012 resource
estimate in 2019, using data from a total of 89 drill holes.
Recent advances in understanding of the mineralisation model at Comstock, and a deep drilling test have suggested significant potential for more Boss-style mineralisation at depth. With the aid of the Tasmanina Government’s drilling initiative EDGI program, AHL completed an 804.5m deep hole in 2019 to explore for mineralisation below the Boss prospect, and that associated with the Balstrup Fault Zone. Results confirm that the mineralisation extends at least 600m below the surface, with multiple high grade lead-zinc zones. More importantly, the results also confirm that the Boss mineralisation is of carbonate replacement type, which opens up a huge space for discovery of a massive lead-zinc mineralisation system at Comstock.
