An exploration drill rig for MMG Rosebery has completed the deepest exploration hole in Tasmania’s rich mining history. The hole, located on the surface of Mt Black, above the mine, was drilled by a 12-man crew from drilling contractor Boart Longyear. The drill hole reached a depth of 2,584 m on May 5 2010. The rig is now drilling some offshoot holes to the west. These will be completed in about a month. Boart Longyear’s drill crew was presented with an award to mark their efforts by local MP Ruth Forrest MLC in a ceremony at Rosebery.
A deep exploration drilling program commenced at Rosebery in November 2009 with two deep surface drill holes targeting prospective areas below the lower parts of the Rosebery ore body. “Our exploration program at Rosebery aims to extend the life of mine beyond our current horizon of around 2020,” said John Lamb, General Manager MMG Rosebery. “Recent exploration has been very encouraging, adding more mineral resources, and suggesting that the prospect of identifying additional reserves is very high.”
Rosebery’s mineral potential was uncovered in 1893 when prospector, Thomas McDonald discovered alluvial gold along with boulders of lead/zinc sulphide in a creek on the southern slopes of Mount Black. Further prospecting by McDonald revealed a lead/zinc sulphide ore body which was mined intermittently from 1893 until the current operation was commissioned in 1936. “We look forward to celebrating the 75th anniversary of the mill and current surface operations here at Rosebery early next year,” said Mr Lamb.
Drilling to this depth poses major engineering challenges that drilling contractor; Boart Longyear was able to meet with their international experience and expertise. “Our combined knowledge of the drill rig used and the ore body meant that we effectively drilled downward to the east, knowing the drill hole would curve round to the west to the target mineralisation zones – a significant engineering feat,” said Mr Lamb.
At the ceremony today Mr Lamb expressed his delight and said “I offer my congratulations to Boart Longyear for the skills and resources they have applied during the drilling of this hole”. “This drill hole demonstrates that MMG is a progressive global company which has a long term vision for the mining industry in Tasmania and specifically demonstrates our commitment to the community of Rosebery,” he said.
Boart Longyear’s Tasmanian Operations Manager Stuart Murdoch said “I am proud of the Mt Black Boart Longyear rig team. Their skills were tested by drilling to this record depth but they have come through as the champion team I know them to be”. “Boart Longyear is proud to be associated with a company like MMG which has a long-term vision for the mining industry in Tasmania and specifically for the community of Rosebery,” he said.
The drill hole began on November 9, 2009 and took 178 days to drill. Four three-man crews operated the drill rig 24 hours a day, 7 days a week. The drill rig had very minimal downtime and this result testifies to the expertise provided by Boart Longyear across each facet of the business.
In presenting the plaque Ruth Forrest MLC congratulated both MMG and Boart Longyear on their outstanding efforts and commitment to exploration and ongoing investment in the mining industry in Tasmania. The Tasmanian economy is largely underpinned by the mining industry and achievements such as this at Rosebery will ensure that this vital contribution to the State’s economy continues for years to come.” she said.
