THE CAMBRIAN STEPTOEAN POSITIVE CARBON ISOTOPE EXCURSION (SPICE) EVENT ON SINO-KOREAN PLATFORM, A REVISIT

The Cambrian SPICE event is a well-known and well-documented stable carbon isotope positive excursion event across the boundary of the Guzhangian-Paibian stages. The global correlation of this GSSP boundary between the shallow-marine Sino-Korean Platform, with mostly endemic trilobites and lack of the biostratigraphically important agnostids, and other paleo-continents had been a well-recognized trilobite biostratigraphic problem that needs to be refined.

In order to tackle this problem, Ng et al. (2014a) reported the first detailed North China SPICE curve from the Shuangqiao (SQ) section, Tangshan area of Hebei Province, and demonstrated that the use of the SPICE data can significantly improve the global correlation of the Guzhangian-Paibian stages boundary, albeit this section was very condensed and using only a couple dozens of stable carbon isotope data points. A second section in the Huangyangshan (HYS) section, Linyi area of Shandong Province, was heavily sampled shortly afterward, and proved that high-resolution SPICE data are definitively required to discuss any details of this event (Ng et al. 2014b). More recently, two more sections, the Baijiashan (BJS) section, Wafangdian area of Liaoning Province, and the Nanzhaocun (NZC) section, Jinan area of Shandong Province, were more heavily sampled and the higher-resolution stable carbon isotope data provided robust datasets of the unexpected weakening of this global signal on the Sino-Korean Platform.

The SQ section was eventually destroyed in mining activity, and the insufficient data resolution is calling for a substitution in the vicinity. A new Banbishan (BBS) section was properly sampled earlier this year and a revisit of this area is going to shed new light on the weakening SPICE signal phenomenon on the Sino-Korean Platform.