ABSTRACT: The Barito River depositional system of South and Central Kalimantan (Borneo); a non-deltaic modern day analogue for the Upper Talang Akar Formation of the Sunda and Asri basins of Indonesia
Gilmore, H. Lee, and Ichsan Sarkawi , Consultant, Bellaire, TX (2) REPSOL-YPF, Dallas, TX
The modern day depositional environments associated with the Barito River and the Java Sea around the mouth of the Barito are, from upstream to offshore, fluvial meander belt, upper estuarine, lower estuarine with lateral coastal plain peat swamps, and inner neritic marine. The reservoir sand bodies currently being deposited by the river exhibit a marked decrease in grain size, areal extent, and frequency of occurrence from upstream to offshore where they become virtually non-existent. The upper Oligocene to lower Miocene upper Talang Akar Formation of the Sunda and Asri basins is an overall transgressive sequence which has been punctuated by several short term regressions. This has resulted in a repetitive series of vertically stacked facies successions which are typically composed of erosive based, fining upward sand bodies overlain in succession by laminated carbonaceous siltstones and shales, coals, marine limestones, and marine shales. Only the upper most series of these facies successions contain marine members. The overall grain size, areal extent, and frequency of occurrence of the reservoir sand bodies decrease vertically upwards. A transgression of the present day Barito River depositional system would result in a vertically stacked succession of facies very similar to those present in the upper Talang Akar Formation of the Sunda and Asri Basins.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia