Abstract

• The Kyun Chaung area is situated in Pakokku District, Magway Region in Central Myanmar. The study area is composed essentially of Cenozoic rock sequences of Lower Pegu Group (Oligocene – Miocene) and Irrawaddy Formation. The rock sequences of the Lower Pegu Group are Padaung Formation, Okhmintaung Formation, (Lower-Upper Oligocene). The detailed petrographic analysis is carried out for the sandstones of the Padaung and the Okhmintaung Formation to obtain the modal compositions of the rock units, diagenetic imprints and provenance study. From the petrographic analysis, sandstones of the Okhmintaung Formations can be regarded as lithic arkose in composition. According to the lithofacies analysis, at least five different lithofacies type can be recognized in Okhmintaung Formation. They are Sand-Mud interlayer facies, Bluish Grey Shale facies, Bioturbated Sandstone facies, Fossiliferous Sandstone facies, and Ripple Sandstone facies. The depositional pattern of Okhmintaung Formation shows a typical cyclic sedimentation pattern occurred in near shore environment. The main economic interest of the KyunChaung area is petroleum extraction from reservoir.