Sulfur continental cycle

The reduction is typically limited by the availability of organic carbon and often occurs in shallow waters at continental margins. Thus, global sulfide production would be dependent on the availability of biological productive areas over geological time. Sulfur-isotope data can be used to constrain simple models of the sulfur cycle over geological time and establish the size of the reservoirs as shown in Figure 5(b). 

Ivanov, M. V., V. A. Grinenko, and A. P. Rabinovich (1983). The sulfur cycle in continental Reservoirs, Part II. Sulfur flux from continents to ocean. In The Global Biogeochemical Sulphur Cycle (M. V. Ivanov and J. R. Freney, eds.), Scope 19, 331-356. 

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