Slight carbon-isotope perturbation at the J/K boundary (base of the Calpionella Zone)- A proxy tool for correlation? A brief summary
Abstract
Stable isotope (813C, 818O) data from bulk rock in the Jurassic-Cretaceous transition are characterised by stability of values in many Tethyan carbonate sections, predominantly those laid down under deeper-water marine conditions. The generally straight trend in the 813Ccarb curve at the J/K boundary interval does not show any significant value expressions that are useful for interregional correlation.
However, in several bio-and magnetostratigraphically well-calibrated sections that have been studied, especially in the Carpathian-Alpine terrain (and some additional sections elsewhere in Tethys), a very slight carbon isotopic negative excursion directly at the J/K boundary (sensu base of the Calpionella Zone/Alpina Subzone) shows an almost identical trend. We assume it represents a rather weak geochemical marker at the Tithonian/Berriasian boundary which, nevertheless, may be identified as a useful tool for strati-graphic correlation. & COPY; 2023 The Authors.
Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).