Coupling of the sedimentary sulfur and carbon cycles - an improved model.

A model of the geochemical cycles of sulfur and carbon during Phanerozoic time makes it possible to compute the masses of the major sedimentary reservoirs, their fluxes in and out of the ocean, and their isotopic compositions both forward and backward in time. Shows a reasonably good agreement between the fluctuations in size of the sulfate reservoir as predicted from sulfur isotopes and the values calculated from carbon isotopes. The exogenic geochemical cycles of carbon and sulfur can be, to a reasonably good first approximation, treated as a closed system. The dominant redox system of the exogenic cycle is the complementary sulfide-sulfate-carbonate-organic carbon relation. -from Authors