Depositional Model for Oligocene-Miocene Deep Marine Deposits of Pamaluan Formation: New Insight to Turbidite Reservoir in Southern Kutei Basin

Abstract The present and future day exploration oil and gas in Kutei basin toward the deep-water Makassar strait area has amplified the significance of understanding its petroleum system. This paper studies deep-water deposits in kutei basin based on numerous outcrops sampled in the field with identify stratigraphic profile, lithofacies, paleocurrent, facies model and paleontological analysis. The lower Miocene Pamaluan Formation outcropping along the sepaku and surrounding area in southern kutei basin has been studied to specific future of its depositional model. Based on outcrop at Mentawir area, Sepaku and outcrop shows that deep marine facies of lobes. Coarse and fine-grained turbidites observed at the outcrop are interpreted as upper -fine deposits with fine-grained facies represent the supra-fan lobe channel and fine grained facies represent the supra-fan lobe interchannel deposits has develop lithofacies association: pebbly sandstone, massive sandstone, gradded bedding sandstone, and clastical turbidites. The overall interpretation of Pamaluan Formation deposition model in Sepaku area and GITAN area is also supported by the occurrence of conglomerate, cross bedding sandstone unit and flute cast indicating upper-fan deposits, as well as flysch and interbedded mudstone indicating lower-fan deposits in Mentawir area. Paleontological studies also found plankton such as Globigerina venezuelana HEDBERG, Globigerinoides primordius and Globigerinides parawoodi. All data is combined to create a sedimentology model of deep marine deposit and constructing paleogeopraphy of Pamaluan Formation model as analog related to turbidite reservoir in the southern kutei basin.