Sedimentology and Paleodepositional Environment of the Early-Middle Miocene Tanjong Formation, Southeast Sabah: Evidence from Bulk Geochemistry and Palynology Analyses

Eight stratigraphic sections from well-exposed outcrops of the Early to Middle Miocene Tanjong Formation in Kalabakan area, southeast Sabah, were investigated using an integrated approach, which a comprehensive sedimentological facies analysis was linked with bulk geochemistry and palynological analyses. The integration analysis, elemental CHNS, Fourier-transform infrared spectroscopy (FTIR), data provided refined evaluation origin organic matter (OM) reconstruction paleodepositional model. Seven associations classified studied 12 lithofacies components, interpreted as environments ranging fluvial-deltaic shallow marine: FA1—Floodplain, FA2—Fluvial channel, FA3—Coastal peat mires, FA4—Tidal flat, FA5—Delta front, FA6—Mouth bar, FA7—Upper shoreface. Evaluation C/N ratio ranged between 4 48, total sulfur content 0.5 3. Elemental CHNS suggests that extracted coal mudstone originated terrestrial plants fresh marine plankton. Accordingly, three most prevalent FTIR spectra samples OH- functional group stretching, absorption spectrum aromatic C=C in-plane/out-of-plane C-H bending. Terrestrially derived within examined further validated by predominance compounds, indicated back-mangrove freshwater pollen assemblage lower coastal plain setting proximal environment. findings this research are vital reconstructing environment model will improve predictability petroleum system mechanisms future hydrocarbon potential for conventional exploration.