Modelling sulfur isotopic compositions in natural marine sediments

Man-Yin Tsang , University of Toronto

The difference in the sulfur isotopic ratios (34S/32S) between (a) dissolved sulfate in seawater and (b) mineral sulfides in marine sediments is produced by microbially-mediated reactions. Nevertheless, isotopic ratios in those two records also depend on physical processes such as diffusion, compaction and advection. Different physical conditions in distinct sites of the oceans can lead to inconsistent values of the differences in 34S/32S measured.

I apply reaction-transport models to account for such physical conditions and to quantify the actual contributions from microbial processes. In this talk, I will highlight findings from the Eastern Equatorial Pacific and my current endeavour at the Nankai Trough accretionary complex east of Japan.