Clumped isotope measurements of Middle to Late Jurassic belemnites and ammonites from the Subboreal Province

Carbonate digestion at 90 °C and subsequent CO2 purification was done on an automated line connected to a ThermoFisher MAT 253 isotope ratio mass spectrometer. We present the raw isotope values calculated using both the [Gonfiantini/Santrock] and the [Brand]/IUPAC isotopic parameters.

The raw data is projected onto the carbon dioxide equilibrium scale (CDES) using the equilibrated gases and without applying any acid fractionation factor to the final values. The origin of sample material, sample preparation methods, and mass spectrometry procedures are further detailed in the associated files and the linked article: Wierzbowski et al. (2018).