The project, discovered in 2006, is one of the world’s biggest recent gold findings, with reserves estimated at about 4.8 million ounces of gold and 6.3 million ounces of silver.
According to the country's chamber of mines, more than a million artisanal miners currently work at about 350 sites, producing between 10 and 15 tonnes of gold a year.
A nickel spike found in sediments above the spot where a giant asteroid hit the Earth some 66 million years ago, may help scientists trace segments of the celestial body that wiped out dinosaurs and 75% of all organisms on the planet.