We define traditional capital delta notation (Delta d) as deviations of d33S from a reference line: Delta d33S = d33S-0.515Xd34S. An alternative Delta delta definition has been preferred by recent studies (Hulston and Thode, 1965, doi:10.1029/JZ070i014p03475; Gao and Thiemens, 1991, doi:10.1016/0016-7037(91)90381-E; Miller, 2002, doi:10.1016/S0016-7037(02)00832-3; Young et al., 2002, doi:10.1016/S0016-7037(01)00832-8), and we denote this as Delta d: Delta d33S = d33S-0.515Xd34S, where dxS = ln(xRsample/xRref)X100 = ln((dxS/100)+1)X1000. Both definitions (Delta d and Delta d) are used for comparison. Note that the modified delta notations (d34S and Delta d33S) are fractionation-oriented (i.e. linear relationships during massdependent isotope fractionation) whereas traditional delta coordinates (d34S and Delta d33S) are mass-balance oriented (i.e. linear relationships during mixing) (Ono et al., 2007, doi:10.1016/j.gca.2006.11.017)