Table T3. Rayleigh sulfur isotope fractionation factor.
Site
Water
depth (m)
R
Jd/(Jd + Jb)
SRR
(mmol/m2/yr)
Leg 201
1225 3760 1.014 0.82 ND
1226 3297 1.040 0.46 14
1227 427 1.019 0.75 82
1228 252 1.023 0.67 573
1229 151 1.018 0.59 681
Leg 181
1119 396 1.015 0.80 ND
1120 544 1.029 0.61 ND
1121 4490 1.009 0.88 ND
1122 4432 1.048 0.36 ND
1123 3290 1.045 0.40 ND
1124 3978 1.040 0.47 ND
1125 1350 1.014 0.81 ND

Notes: R = minimum isotope fractionation under apparent closed system, conditions calculated based on pore water sulfate profiles in the upper sulfate zone (see text). Estimated R values for the deep (brine influenced) sulfate zone were found to be 1.028 (Site 1228) and 1.022 (Site 1229). Openness of the sedimentary system toward dissolved sulfate (Jd/[Jd + Jb]) are calculated based on the relationship derived by Claypool (2004; see text). SRR = depth integrated sulfate reduction rates, measured with radiotracers in the whole sulfate zone (J. Kallmeyer and T.G. Ferdelman, pers. comm., 2004). Results are compared to sites from the southwest Pacific (ODP Leg 181; Böttcher et al., 2004b). ND = not determined.