Authigenic Carbonate and the History of the Global Carbon Cycle

作者：Schrag, Daniel P.^*; Higgins, John. A.; Macdonald, Francis A.; Johnston, David T.

来源：Science, 2013, 339(6119): 540-543.

DOI：10.1126/science.1229578

• ATMOSPHERIC OXYGEN
• ORGANIC-MATTER
• SEDIMENTS
• OCEAN
• EARTH
• EXTINCTION
• DELTA-C-13
• EVOLUTION
• ORIGIN
• RECORD

We present a framework for interpreting the carbon isotopic composition of sedimentary rocks, which in turn requires a fundamental reinterpretation of the carbon cycle and redox budgets over Earth's history. We propose that authigenic carbonate, produced in sediment pore fluids during early diagenesis, has played a major role in the carbon cycle in the past. This sink constitutes a minor component of the carbon isotope mass balance under the modern, high levels of atmospheric oxygen but was much larger in times of low atmospheric O-2 or widespread marine anoxia. Waxing and waning of a global authigenic carbonate sink helps to explain extreme carbon isotope variations in the Proterozoic, Paleozoic, and Triassic.

• 出版日期2013-2-1