The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
Northern Dynasty says discovery may significantly enhance size and overall grade of Pebble copper-gold deposit near Iliamna
Vancouver, British Columbia-based Northern Dynasty Minerals Ltd. has discovered a significant new porphyry copper-gold system at its Pebble project in near Iliamna in Southwest Alaska, according to Ronald Thiessen, company president and CEO. The discovery has the potential to significantly enhance the size and overall grade of the Pebble deposit, Thiessen said in a Sept. 21 statement.
Based on a March 2005 estimate, the Pebble deposit contains measured and indicated resources of 3 billion tonnes, including 31.3 million ounces of gold, 18.8 billion pounds of copper and 993 million pounds of molybdenum, with an additional inferred resource of 1.1 billion tonnes, containing 10.8 million ounces of gold, 5.9 billion pounds of copper and 361 million pounds of molybdenum using a 0.30 percent copper-equivalent cut-off grade. The company is currently preparing a feasibility study for completion in December, based on the extraction of 2.6 billion tonnes of ore from the currently defined resource.
New drill holes at the eastern edge of the Pebble deposit led to the new discovery, which will be studied, but will not impact the current feasibility study, according to Bruce Jenkins, COO of Northern Dynasty Mines Inc. (Alaska).
"The mineralization on the eastern edge of the Pebble deposit is significant, but until it is further delineated, we will not know how it might fit into the overall development," Jenkins told Mining News.
Mid-point 2,000 feet east of deposit
In the Sept. 21 statement, the company said its core hole 5327 entered a new mineralized system at a vertical depth of 1,500 feet below surface, with a mid-point of the intercept located 2,000 feet east of the Pebble deposit. The core hole had an intersection of 2,619 feet grading 1.45 percent copper equivalent, or 0.87 percent copper, 0.70 grams gold per ton, and 0.028 percent molybdenum. Included in the intersection are intervals of 605 feet grading 1.6 percent copper equivalent, or 0.90 percent copper, 1.06 grams gold per ton, 0.013 percent molybdenum, and 290 feet grading 2.00 percent copper equivalent, or 1.08 percent copper, 1.30 grams gold per ton, and 0.029 percent molybdenum.
Of the drill holes for which assays are available, hole 5327 - which is the completed hole farthest to the east - has the highest grade over its entire length and at depth, indicating that it is nearest to the hydrothermal center, which may be still farther to the east, the company said, adding that the hole was terminated while still in higher-grade mineralization greater than 1 percent copper equivalent because of the depth limitations of the drill.
Could add to interest in project
If further testing indicates the new discovery will add substantially to currently identified reserves while enhancing the overall grade, the Pebble project will attract greater interest from the world's largest mining companies, according to Laurence Roulston, geologist and editor of the newsletter Resource Opportunities.
"I think this size and grade will be irresistible to major mining companies," Roulston told Mining News. "The largest mining companies will be swarming all over this."
Northern Dynasty said it will spend C$44.7 million in 2005 on a work program consisting of drilling, engineering and environmental/socioeconomic work to complete its December feasibility study and prepare environmental permit applications for submission in 2006.
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