LINKED LOWSTAND DELTA TO BASIN-FLOOR FAN DEPOSITION,OFFSHORE EAST KALIMANTAN:AN ANALOGUE FOR DEEP-WATER RESERVOIR SYSTEMS

摘要

In the offshore East Kalimantan,3D seismic reflectors can be traced downslope from a Pleistocene lowstand delta to the basin-floor fan,giving insight into the distribution of sands in ancient deep-water settings.The cycles on the shelf were dominated by progradational packages deposited during highstands and falling eustatic sea level.During the last two lowstands of the sea level(approx18 and approx130 ka),coarse clastics were not deposited in deep-water environment because existing growth faults and regional subsidence prevented lowstand deltas from reaching the slope.During the lowstand of sea level that ended at-240 ka,a delta prograded over the previous shelf edge,and sand-rich sediments spilled onto the slope.A canyon on the slope connected the 240 ka lowstand delta to a coeval basin-floor fan.The canyon has a sinuous fill that consists of a lower,amalgamated channel complex and an upper channel-levee complex.The basin-floor fan at the toe of the slope can be differentiated into two parts.The stratigraphically lower part of the basin-floor fan has broad lobes with relatively continuous reflectors.