中国科学院南京地质古生物研究所机构知识库

In a recent communication on carbon isotope chemostratigraphy of the uppermost Cambrian strata, it was claimed that the Top of Cambrian Excursion (TOCE) is (1) an undocumented negative delta C-13(carb) excursion; (2) ambiguously defined; (3) deliberately fictitious or, in the authors' words, a 'nihilartikel'; and (4) not synonymous with the Hellnmaria-Red Tops Boundary (HERB) Event. As the authors who have been involved in much of the discussion surrounding the TOCE since its introduction and in subsequent clarification, we wish to emphasize that the recent communication overlooks the fact that the TOCE is in fact a well-documented and clearly defined negative delta C-13(carb) excursion, and that the term 'HERB Event' was originally used informally, without definition or reference data, for a negative delta C-13(carb) peak, a peak later shown to occur within the TOCE excursion. Nearly a decade after the TOCE was named, the concept of the HERB Event was modified from a negative delta C-13(carb) peak to a negative delta C-13(carb) excursion, making it conceptually synonymous with the TOCE excursion. The recently published commentary is misleading and replete with misconceptions, as we discuss here.