Changes of TOC and δ¹⁸O, δ¹³C from Globigerinoides ruber during the Deposition Process in the Southern South China Sea

Key words: 
• Globigerinoides rubber /
• isotope /
• total organic carbon(TOC) /
• deposition process /
• southern of South China Sea

Abstract: The ocean sediments are formed in surface water and finally preserved in sea floor. During this process, the sedimentary environment always changed. In this paper, the change characteristics of TOC(%), TOC flux and δ¹⁸O and δ¹³C values from Globigerinoides ruber during the deposition process had been discussed in detail, basing on analyzing the relationships among particulate matter, surface sediment and core sediment in Southern of South China Sea(SCS). Here, the results shown that:1) The different proxies, such as TOC(%), TOC flux and δ¹⁸O,δ¹³C, have different changes during the deposition process. Specially, all the values of TOC(%), TOC flux and δ¹⁸O,δ¹³C descended visibly during the deposition satge from deep water layers to sea floor. The value of TOC% and TOC flux descend from 4.20%, 0.38 g/(cm²·ka) to 1.182%, 0.039 g/(cm²·ka), respectively. The value of δ¹⁸O,δ¹³C descend from 3.298‰ and 0.431‰ to 2.923‰ and 1.461‰, respectively. Reversely, when the core sediment formed in sea floor, the value of δ¹⁸O,δ¹³C would become stable except TOC(%) and TOC flux; 2) The relationship between TOC(%) change and value of δ¹⁸O, δ¹³C become visibly when the core sediment formed. Specially, there are clearer coherence between TOC(%) and value of δ¹⁸O in core sediments than other sediment types. In other hand, the change of relationship between TOC(%) and value of δ¹⁸O and δ¹³C indicate that the dissolution of TOC might be one of important factors leads to change of δ¹⁸O and δ¹³C value. In one word, the change characteristics of TOC(%), TOC flux and δ¹⁸O, δ¹³C during different sedimentary stages must be considered when reconstruct the palaeoenvironment evolution history based on these proxies.