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Carbon-isotope evidence reported from 3.7 Ga Isua sediments

1999 · Recorded · culture

The source states this happened, and its date is not in the future. The word the source used for it is historical.

Minik Rosing reported graphite microparticles in more than 3,700 million-year-old seafloor turbidites from Isua in West Greenland whose carbon-13 content is depleted to a degree characteristic of biological carbon fixation. Organisms preferentially take up the lighter isotope, so biological carbon is isotopically light and the residual inorganic pool is correspondingly heavy — a fractionation that is easy to measure and hard to produce abiotically at the same magnitude. The claim is important because it does not depend on any structure being biological in shape, which is the weak point of every stromatolite and microfossil claim of comparable age. Its own weak point is that certain abiotic reactions, including some hydrothermal and metamorphic processes, can produce isotopically light carbon, so the argument turns on how large a fractionation is achievable without life.

Source

Science · Rosing, M. T., Science, vol. 283 (1999), pp. 674–676

Standing

This record: partially verified · publisher: partially verified

How it arrived

Editorial — A dated record from the Richseen Atlas editorial corpus, written and cited by a curator. Not captured from anywhere, and not live.

Where

At a canonical Atlas object, placed and checked by a curator.

Subject

Isua supracrustal belt, southwest Greenland