The research area is located in Mekar Sari Village and surrounding areas, Sosoh Buay Rayap Sub-District, Ogan Komering Ulu District, South Sumatra Province. This study's aim is to identified the provenance of the Gumai Formation sandstones in the study area based on petrographic analysis on thin sections from seven sandstone samples taken in the study area. Megascopic analysis, petrographic ana…