ANCHORAGE - The potential for riches keeps growing at Pebble Mine, a huge minerals deposit in southwest Alaska near Bristol Bay and the world's most productive wild salmon streams.
A new estimate released Monday is larger than the 2008 estimate - growing 12 percent for copper, 14 percent for gold and 16 percent for molybdenum, which is used to strengthen steel.
Pebble contains an estimated 80 billion pounds of copper, over 100 million ounces of gold and 5.6 billion pounds of molybdenum, said Canadian-based Northern Dynasty Minerals Ltd., which is developing the prospect with London-based Anglo American PLC.
The estimate is for both measured and indicated, and inferred amounts.
The updated estimate was achieved through drilling 37 new core holes since mid-2008, bringing the number to 509, the mining companies said in a news release.
Northern Dynasty's President and CEO Ron Thiessen said Pebble has the potential to be "one of the great metal producers of the 21st century."
"Based on this estimate, the Pebble Project has further entrenched its status among the top-tier of global copper and molybdenum resources, and the most significant undeveloped gold resource in the world," Thiessen said.
Numerous Alaska Native groups in the region are opposed to Pebble out of concern for what it will do to the Bristol Bay salmon they rely on for food. A growing list of jewelers, including Tiffany & Co., also are opposed because of the mine's location and have vowed not to buy gold from Pebble. Many commercial fishermen also remain opposed to Pebble, fearing it is a threat to their livelihoods.
The mining companies hope to have a preliminary development plan done by the end of the year with permitting to begin in 2011, said Mike Heatwole, spokesman for the Pebble Partnership in Anchorage.
Pebble is actually two mines, Pebble East and Pebble West. The focus remains on Pebble East where the minerals are of higher quality but deeper in the ground, probably requiring an underground mine. Pebble West, if developed, would be an open pit mine.
Heatwole said an underground block caving mine with draw-points is being considered for Pebble East. That involves mining under the deposit, and once the minerals are extracted, the mine eventually collapses on itself.
The preliminary development plan will answer numerous questions about Pebble, including what style of mine will be built, how the rock will get to a port facility and how the mine will be powered. A prefeasibility study of engineering, environmental issues and project economics also will have to be completed before permitting begins.
Pebble could provide 2,000 jobs during construction and 1,000 jobs when in operation, Heatwole said.