AngloGold Ashanti CEO Alberto Calderon said three-quarters of company output already comes from tier-one assets and the aim is 85% by the mid-2030s. Credit: Henry Lazenby Colorado Springs – A year of record bullion prices has the gold sector talking less about buying ounces in takeovers and more about finding them in their midst.At the Mining Forum Americas in Colorado Springs, the industry’s biggest producers, streamers and would-be builders struck a rare consensus this week: stick to tier-one assets, kee ...