The Ripsok Formation, which dates back to Pennsylvanian age, is one of the most typical transitional zones in Kangso-Samdung synclinorium.
Studies of the Ripsok Formation have focused mainly on lithostratigraphy, biostratigraphy and palaeontology; and detailed sedimentological research and study of microfacies are still needed.
Kim Myong Hak, a section head at the Faculty of Earth Science and Technology, investigated the microfacies and sedimentary environment of the Ripsok Formation in the Sungho area.
In the study area, the Ripsok Formation was subdivided into 2 microfacies that are characterized by petrographic analysis based on their depositional textures and fauna. In addition, one major depositional environment was identified in the Ripsok Formation. This is a shelf lagoon, which was interpreted as a transition zone separating the platform from the open ocean.