The Bengalon River is located in East Kalimantan, close to the northeastern margin of the Kutei Basin (Fig. 1). A thick Paleogene and Neo- gene sedimentary package occur in this area, ranging from deep marine to fluviomarine depositional environments. This short note discusses the Early Miocene deep marine carbonates, particularly the calci-turbidite deposits. Dark gray, massive calcareous shales intercalated with bioclastic limestones dominate the calci-turbidite sequence in this area (Fig. 2). These limestones range from mudstones to grain- stones and packstones. They are white to gray in color, generally massive, and locally show grading and reverse grading with reworked large foraminiferal, algal and coral fragments. Beds are generally 0.5-5 cm in thickness and are lenticular or nodular in places. Subunits C, D, and E of the Bouma Sequence, which indicates distal turbidites, are common within bioclastic limestone beds. Thinning and fining upward sequences of bioclastic limestones occur in some part within the calci-trubidite unit (Fig. 3). They begin with 40-70 cm thick rudstone to grain- stone interbeds and generally end with 5-10 cm mudstone to packstone interbeds. The thicker interbeds commonly begin with Bouma's subunit A with graded bedding, and change upward to Bouma's B and C subunits with parallel laminated and wavy laminated beds. This package indicates mid-fan channels or lobe shifting facies. Disorganized rudstone to boundstone conglomerates, corresponding to disorganized beds of Walker's resedimented conglomerate model (Figure 4; 1975), were also recognized as sub-facies within the calci-turbidite se- quence. This polymictic debris is rudstone to boundstone debris flow deposit, with lime- stone, calcareous sandstone, and calcareous shale fraynents. The largest fragment found was approximately two meters in diameter and was coralline limestone. No internal structures are visible within this unit. In the submarine fan depositional model, the thick bedded rudstones interpreted as a debris flow correspond to upper-fan slope deposit. The rudstone to mudstone interbedded in shale subfacies may have come from either within lobes of a lower fan or within a upper to mid fan position. Paleontological analyses indicate an Early Miocene N4 age in a bathyal marine environment. The presence of carbonate sediments strongly suggests that an active carbonate-producing shelf existed somewhere landward at the same time. REFERENCE Walker, R. G., 1975, Generalized facies models for resedimented conglomerates of turbidite association: Geological Society of America, Bulletin, v. 86, p. 737-748. ACKNOWLEDGEMENT The permission of Lasmo Runtu Ltd and partners to publish this paper is gratefully acknowledged. Clif Jordan is thanked for his comments on the manuscript. The author is grateful to Dharma Satria Nas (GRDC) and John Chambers (Lasmo Venezuela) for discussions on depositional model.