#TITLE_ALTERNATIVE#

• Main Author: YUSMANANTO (NIM 12007015), SANI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/13827
• Institution: Institut Teknologi Bandung

The study area is located in Mount Besar area, Mangkalihat Peninsula Village, East Kutai Regency-East Kalimantan, covering an area of ± 26 km2 (4 km x 6.5 km). Geographically, the study area is located at UTM 50 N 698000-704500 m E 104000-108000 m. The objectives of this study are to determine the geological conditions and limestone diagenesis product analysis of Lembak Formation and its relationship with the diagenetic environment that has been traversed. Physiographical research areas are on Mangkalihat Ridge Zone. Geomorphological units in research area consist of Karsts Hills Unit, Karsts Terrain Unit, and Homoclinal Hills Unit. Lithostratigraphy units from old to young consists of Reef Limestone Units, parallel with Lembak Formation, aged Late Oligocene - Early Miocene, was deposited in the Shallow Marine Environment. Limestone Calcarenite unit, parallel with Golok Formation, aged Middle Miocene, was deposited in the Middle Neritic Environment. Marl unit, parallel with Golok Formation, aged Middle Miocene -Late Miocene, was deposited in the Outer Neritik – Upper Batial Environment, and Alluvium Unit, aged Resen, deposited in terrestrial environments are not aligned above the Marl Units. Geological structures in the study area consist of reverse fault trending southwest – northeast and strike slip fault trending northwest -southeast. The forming of these structures is controlled by main emphasis trending northwest – southeast from the movement of Mangkalihat and Sangkulirang Fault, estimated to occur in Pliocene - Pleistocene. The diagenesis analysis has been done on the limestone Lembak Formation through a thin section and fairly well observed the diagenetic products, such as microbial micritization, cementation, compaction, neomorphism, and dissolution. Diagenetic environments obtained from the analysis of diagenetic products consists of four diagenetic environment, namely; marine phreatic, burial, meteoric phreatic, and meteoric vadose.