Abstract:

The organic carbon isotope compositions were examined for the first time from a well-preserved deep-water PTB section (Dongpan section) in Liuqiao area, Guangxi.The global correlation comparison is carried out by organic carbon isotope stratigraphy between Dongpan section and GSSP at Meishan section in Zhejiang.There are remarkable similarities and differences between theδ¹³C_orgtrends of both sections. In Dongpan section, a remarkable negative excursion occurs after the onset of ‘PTB events’, which is similar to Meishan section, and was accompanied by the mass extinction of radiolarian, volcanic activities and sea level fall.The recovery towards more enriched δ¹³C_org values at Meishan section occurs in a zone of bed 27, but continued negative δ¹³C_org values throughout the lower Induan in Dongpan section coincide with the marked recovery lag, which is probably related to continuously adverse conditions in the Early Triassic.

Key words: organic carbon isotope, Permian/Triassic boundary, deep-water deposit, Dongpan section, Liu-qiao area, Guangxi