/newsroom/taxonomy/term/3351/all en /newsroom/channels/news/mining-ancient-ores-clues-early-life-219461 <p>An analysis of sulfide ore deposits from one of the world’s richest base-metal mines confirms that oxygen levels were extremely low on Earth 2.7 billion years ago, but also shows that microbes were actively feeding on sulfate in the ocean and influencing seawater chemistry during that geological time period.</p> Mon, 10 Dec 2012 17:48:22 +0000 christopher.chipello@mcgill.ca 12313 at /newsroom