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On the fringe of Chile's northern desert, amid the towering peaks of the Andes mountains, millennial glaciers have formed some 5,000 metres high, where the temperature is cool enough to freeze water and capture rainfall. Meltwater from these glaciers gives way to crystalline streams that nourish the fertile valleys below. Grapes, papayas, lemons and olives abound in the Huasco Valley, and fishermen harvest mud shrimp from the rivers that give it life. But prospecting has revealed this valley is also home to riches of another kind. The mountains are a spectacular array of purple, pink, green and orange--the result of mineral deposits, including copper, iron, silver and gold.
Canadian mining giant Barrick Gold Corp.--the third-largest gold producer in the world--acquired rights to a large portion of this land in 1994. At the time, the site's gold reserves were estimated at 1.8 million ounces. But over the course of the past decade, through drilling and exploration, Barrick discovered that reserves are almost 10 times that: an estimated 17.6 million ounces. Barrick produces about 5.5 million ounces annually, with reserves at 89 million ounces. So this site, which straddles the Argentina-Chile border and which the company has baptized Pascua-Lama, represents 20% of Barrick's reserves. (In Argentina, Barrick has already begun construction of the Veladero site, where there are another 12.9 million reserve ounces.) One problem: there are three millennial glaciers covering portions of the site where they've proposed to build an open-pit mine.
To get at the gold, Barrick plans to relocate portions of the three glaciers--70% of the Esperanza glacier, 4% of Toro 1 and 20% of Toro 2. All told, they span 34 hectares. The plan involves moving about a third of that--or 10 hectares of ice. "For engineers and the like, this is not a complicated thing," explains Barrick's vice-president for corporate communications, Vincent Borg. "The environmental viability of the ice relocation is not based on any complex energy balances or any sort of unusual hydrological conditions. It's a logistical challenge more than anything."
The proposal is surprisingly low-tech. It involves hydraulic shovels that will dig into the glaciers, scoop up large chunks of ice and dump them into 240-ton trucks that will transport them two kilometres to the southern face of the larger Guanaco glacier. The whole process would take four to six months. "Because you're doing it at the tail end of winter, as you get into spring, I think the average temperature is about 0ûC anyway, so the ice is not about to melt anywhere," explains Borg. "It's also within the same water basin, so there will be hardly any impact on the water flow that would naturally come from the glaciers."
But Barrick's plan, costing between US$1.4 billion and US$1.5-billion, has sparked controversy. The company faced tough questions about its science at government hearings in Santiago on April 18. Renowned Argentine biologist Raul Montenegro called Barrick's environmental impact study "weak" and denounced the miner's record at the Veladero mine. He said Barrick is treating the glaciers like "piles of ice" rather than an essential part of a fragile desert ecosystem. "We live on the fringe of the desert, so water is precious to us," says local farmer Ramiro Barrera in the hamlet of Chollay. "We worry that losing these glaciers will reduce our river flow."
Barrick counters that extensive field studies show there won't be "any significant impact" on either the quality or the quantity of their waters. "The amount of glaciers or icefield that we are planning to remove is 1% of the overall volume of glaciers in that area," says Borg. "We're also proposing to build a channel so that any of the water that would flow over the areas we're mining will be protected and channelled down." Barrick will hand in a detailed glacier management plan in the coming weeks. Getting all the needed environmental and government approvals to mine the site could take months, so Barrick isn't planning to begin construction of Pascua-Lama until early 2006. It takes time to move mountains.
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