Porosity Modification, A Key To The Carbonate Diagenetic Environments. Case Study: Reefal Limestone, Marah Formation, Miau Baru, East Borneo, Indonesia

Abstract

Abstract Through the Eocene-Oligocene transition, localised carbonate shoal formed the northern part of Kutai basin. Miau Baru is a small village located in Kongbeng sub-district, East Kutai, NE Borneo which has a relatively narrow area with complex geological features. This relatively thick the carbonate successions of Marah Formation previously have less attention from diagenetic perspective. To achieve the objective in this diagenetic study of the reefal limestone of Priabonian-Rupelian Marah Formation, limestone samples were collected and sectioned. A total of 35 samples were selected, 25 from Goa Indah section and 10 from Kongbeng section. This paper compiles current knowledge on the sedimentology aspects of this Kongbeng complex region and includes the first attempt to synthesise petrographic data onto carbonate diagenetic environment and history in Miau Baru Area. Detailed identification of porosity modification helped to reconstruct carbonate diagenetic environment and its application in expecting a petroleum reservoir for the region, thereby highlighting areas where further geological research is required.