The Palaeocene-Eocene Thermal Maximum (PETM) is recognized as a significant climatic event in the Cenozoic era, marked by negative carbon excursions, rapid warming, and ocean acidification. However, stable isotope analysis of carbonates poses challenges due to diagenesis. This repository presents a comprehensive study of diagenetic features within the Zranda section, which represents shallow carbonates of the eastern Tethys. Through meticulous examination, this dataset facilitates the identification of minimally affected samples, enhancing their suitability for stable carbon isotope analysis.Each sample was drilled with a dental drill to obtain 4 mg of powder for bulk carbonate stable isotope analysis. The best-preserved sections were targeted, avoiding visually altered areas due to diagenetic processes. Carbon and oxygen isotopes were measured using an IBEX system connected to a Thermo Fisher-MAT 253 Plus stable isotope mass spectrometer at Macquarie University's GeoAnalytical facility. The powder underwent reaction with 105% phosphoric acid at 90°C in a stirred acid bath. CO2 gas evolved from the reaction was isolated and filtered through cold traps and a sulfur-trap before being concentrated into a micro-vessel for analysis. Accuracy was monitored using an in-house Carrara marble standard and clumped isotope carbonate standards (ETH 1, ETH 2, ETH 3, and ETH 4). Isotopic values were calculated using Easotope software.