Sr isotopic compositions of cold seep carbonates from the South China Sea and the Panoche Hills (California, USA) and their significance in palaeooceanography

87Sr/86Sr ratios, δ13C and δ18O values, and concentrations of Sr and Mn in cold seep carbonates collected from the South China Sea and the Panoche Hills (California, USA) are determined in this study. The carbon isotopic values of carbonates reflect different carbon sources. Carbonate samples with high Sr concentrations and low Mn/Sr ratios are considered to have very little or no influence by diagenetic alteration. Sr isotopes of seep carbonates from both the South China Sea and the Panoche Hills record the information on the original seawater or pore water. Together with the published Sr isotopic data of cold seep carbonates in Italy, we applied the Sr isotope stratigraphy (SIS) and SIS LOWESS Version 3 curve to calibrate the ages for the cold seep carbonates. These ages are consistent with their sedimentary strata, indicating that the cold seep carbonates, with high Sr concentration and low Mn/Sr ratio are good candidates for dating by their Sr isotopic compositions.