Based on petrographic analysis, the research studies the limestone diagenesis of Ngrayong Member of the Tuban Formation, Kayen Region, Bancar District, Tuban Regency, East Java. Ngrayong a Member of the Tuban Formation is one of the formations included in the North East Java Basin. Regionally, the research area is included in the North East Java Basin. The limestone of Ngrayong a Member of the …