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.The thin sections of Zranda section were studied under polarizing Nikon Eclipse 50iPOL petrographic microscope with at 5X objective lens, a Nikon DS-Fi1 digital camera and Prior motorized stage. Different diagenetic features were in identified and samples were classified into 1) marine phreatic, 2) shallow burial or 3) shallow to deep burial diagenetic environments, using previously established petrographic criteria (Chilingar et al., 1967; Madden et al., 2017).