Biogeochemistry of Sulfur Isotopes

Sulfur, with an atomic weight of 32.06, has four stable isotopes. By far the most abundant is 32S, representing around 95 % of the total sulfur on Earth. The next most abundant isotope is 34S, followed by 33S, and finally 36S is the least abundant contributing only 0.0136 % to the total (Table 1). The natural abundances of sulfur isotopes, however,