Upper Cambrian and lower Ordovician conodont and carbon isotope bio-chemostratigraphy of the eastern North China Platform: Implications for global correlation and palaeoenvironments

Revised conodont biostratigraphy and new carbon isotope data through the Cambrian/Ordovician transition are presented for the Yaowangshan section in the eastern North China Platform. Eight conodont zones are recognized, including the Proconodontus muelleri Zone, Eoconodontus Zone, Cordylodus proavus Zone, C. caboti Zone, C. intermedius Zone, C. lindstromi Zone, C. angulatus Zone, and Rossodus manitouensis Zone, in ascending order. The Eoconodontus Zone can be subdivided into the E. notchpeakensis Subzone and the overlying Cambrooistodus minutus Subzone. The new delta 13Ccarb data from the Chaomidian Formation are well constrained by the conodont biozonation and indicate pronounced carbon excursions and spike, Top of Cambrian Excursion (TOCE), Cordylodus proavus spike (CPS), and Cambrian-Ordovician Transition Isotopic Carbon Excursion (COTICE). The isotopic excursions are generally consistent with those of other sections in North China, South China, Tarim, North America, Argentina, and Baltica.