In this study, we have followed published guidelines for the expression of stable isotope ratio measurement results but expressed all delta values in the common format as 1000 delta in permille (‰). The full mathematical algorithms used in the calculation spreadsheets  are included in the supplementary materials available here:

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TABLE 1 Conversion equations for stable isotope composition of elements with two stable isotopes
   

TABLE S1 Conversion equations for stable oxygen isotope composition for sample P

 

TABLE S2 Conversion equations for stable sulphur isotope composition for sample P