Questioning the evidence for Earth's earliest life—Akilia revisited

It has been argued that apatite crystals containing inclusions of isotopically light graphite in a quartz-pyroxene rock from the island of Akilia, southwest Greenland, represent the earliest (older than 3.85 Ga) traces of life on Earth. Although the age and protolith of this rock have been subjects of vigorous discussions, the occurrence of isotopically light graphite inclusions in Akilia apatite has so far not been debated in the literature. We present here the results of petrographic analysis of 17 different Akilia samples, including the actual sample (G91-26) used in the original study. Our finding that none of the apatite crystals in these samples contain graphite inclusions indicates that the Akilia apatite has no bearing on claims pertaining to a past record of life on Earth.

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