Sulfur isotopic processes, applications

There are several review papers on mass-independent chemical processes and their applications. Thiemens and Weston reviewed the progress in understanding the physical chemistry of gas-phase mass-independent processes and their observation on Earth and meteorites. Thiemens et al. (2001) reviewed the observations of mass-independent isotopic composition in various solid reservoirs of Earth and Mars, including both oxygen and sulfur isotopes. A more recent review (Thiemens, 2002) has summarized the theoretical and laboratory studies of the physical chemistry of mass-independent isotope effects and their observation on Earth and Mars, subsequent to the review of Thiemens et al. (2001). 

Krouse and Mayer (2000) present an in-depth review and several case smdies of the use of stable sulfur and oxygen isotopes of sulfate as hydrologic tracers in groundwater. In addition, the use of sulfur isotopes for investigations of hydrological processes in catchments has been reviewed by Mitchell et al. (1998). Thus, what is presented here is just a brief overview of the application of sulfur isotopes in hydrologic studies. 

Mid-ocean ridge hydrothermal processes provide an ideal application for geochemical reaction path modeling, involving temperature dependent reactions, fluid mixing, reaction with sulfide products, and reaction with seafloor basalts (5). The solution and solid compositions are well characterized, including that of sulfur isotopes (10.11). However, measured fractionations between solution and solid samples can not be the result of simple equilibrium processes f 10-121. The ability to track reactions involving seawater sulfate = 21 per mil) and hydrother-... 

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