The late Precambrian greening of the Earth

  title={The late Precambrian greening of the Earth},
  author={L. Paul Knauth and Martin Kennedy},
Many aspects of the carbon cycle can be assessed from temporal changes in the 13C/12C ratio of oceanic bicarbonate. 13C/12C can temporarily rise when large amounts of 13C-depleted photosynthetic organic matter are buried at enhanced rates, and can decrease if phytomass is rapidly oxidized or if low 13C is rapidly released from methane clathrates. Assuming that variations of the marine 13C/12C ratio are directly recorded in carbonate rocks, thousands of carbon isotope analyses of late… Expand
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