Research on limestone microfacies studies was carried out in the Tuban Formation, Ngrayong Member, located in the Ngujuran and Surrounding areas, Bancar District, Tuban Regency, East Java. The research area is in the North East Java Basin, Rembang zone. The Tuban Formation of the Ngrayong Member is composed of carbonate rocks, including limestone, sandstone and claystone inserts. The clastic li…