Project description:This petrographic database is a compilation made to study the Oligocene-Langhian succession of the Arquata Scrivia area, consisting of different shallow to deep-water marine sedimentary units deposited in the eastern Tertiary Piedmont Basin (NW Italy). This database is unique for the studied succession, which was not priorly investigated for the petrographic content of its component units. The samples were collected from lower, middle and upper parts of each sedimentary unit and analyzed for identifying their petrographic composition via qualitative and quantitative methods by means of polarized-light microscope. The collected petrographic data are presented within quartz-feldspar-lithic ternary plots. Even though these data are elementary analytical outputs, they represent the starting point for future analyses in order to understand the evolution of the basin on a larger scale.