It is proposed that a new global redox carbon cycle model be created. It claims that the movement of the lithosphere plates has an effect on photosynthesis growth. Periodic injections of CO2 from plate collision zones are used to create the effect. In subduction zones, carbon dioxide is produced by the oxidation of sedimentary organic carbon during thermochemical sulphate reduction. Carbon turnover is characterised as the transformation of an element from its oxidised state (CO2 + HCO3- + CO32-) to its reduced state (CO2 + HCO3- + CO32-) as a result of photosynthesis and subsequent transformations. The isotopic data back up the model's validity. They clarify why the carbon isotope composition of sedimentary organic matter corresponds with geologic age. The discrepancy between the carbon isotope composition of organic matter and that of coeval carbonates was discovered to be an analogue of the carbon 13C isotope discrimination used by modern plants in photosynthesis. Isotopic periodicity coincides with the periodicity of climatic shifts, mass extinctions, the irregularity of stratigraphic distribution of organic-rich rocks, and other periodic occurrences in the biosphere. The model describes how the evolution of photosynthesis contributed to the accumulation of oxygen in the atmosphere and sedimentary organic matter in the Earth's crust, and how these developments gradually led to an ecological compensation point in the global carbon cycle system. At this point, all of the system's parameters stabilised and started to oscillate around a fixed point.
Author (s) Details
A.
A. Ivlev
Russian
State Agrarian University of K. A. Timiryazev, Moscow.
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