Evidence of Earth's Oldest Life?

Carbon found within ancient rocks has played a crucial role developing a time line for the emergence of biological life on the planet billions of years ago. But applying cutting-edge technology to samples of ancient rocks from northern Canada has revealed the carbon-based minerals may be much younger than the rock they inhabit, a team of researchers report in the latest edition of the journal Nature Geoscience.

The team – which includes researchers from Boston College, the Carnegie Institution of Washington, NASA's Johnson Space Center and the Naval Research Laboratory – says new evidence from Canada's Hudson Bay region shows carbonaceous particles are millions of years younger than the rock in which they're found, pointing to the likelihood that the carbon was mixed in with the metamorphic rock later than the rock's earliest formation – estimated to be 3.8 to 4.2 billion years ago.

The samples come from the Nuvvuagittuq Supracrustal Belt, a sedimentary banded iron formation located in the Archean Superior craton, one of the earth's ancient continental shields. Samples were subjected to a range of high-tech tests in an effort to more clearly characterize the carbon in the rock. …

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