Sr isotope composition in belemnites from the Jurassic–Cretaceous boundary section (Maurynya River, Western Siberia)

Аннотация

The belemnite Sr isotope characteristics obtained over an interval from the Upper Volgian Regional Substage to the lower part of the Ryazanian Regional Stage in the section on the Maurynya River (Western Siberia) fills a gap in the ⁸⁷Sr/⁸⁶Sr ocean water variation curve over the Jurassic–Cretaceous boundary. The increase in the ⁸⁷Sr/⁸⁶Sr values from 0.707172 to 0.707242 revealed in the section coincides with a general rise in this ratio in the Late Jurassic–Early Cretaceous ocean.