Modern Tropical Deltas in Indonesia and Surrounding Areas

Bachtiar, Andang ¹; Purnama, Yudi Satria ¹; Krisyunianto, Andi ²
(1)Exploration Think Tank Indonesia, Jakarta, Indonesia. (2) GDA Consulting, Jakarta, Indonesia.

A total of 372 deltas in Indonesia, Brunei, Malaysia, East Timor and Papua New Guinea have been identified and classified based on remote sensing on satellite data, and some of them have been visited and preliminary sampled for ground-truth checking. The deltas share the similarity of having very pronounced suspended load sediments indicated by turbidity reflected by several typical responses on the satellite images. Wave-dominated delta predominates the type of the deltas being investigated, e.g.: 323 or 87% out of the total 372 deltas.

Big islands tend to have more numbers of and bigger deltas, but not all the rivers that drained big islands are always associated with big delta developments. Shoreline river downstream area with less or no tectonic activity, i.e.: subsidence, usually develops extensive coastal plain area instead of delta. Huge accommodation spaces created by tectonics both in Mahakam and Mamberamo Deltas have positively correlated with big delta developments there.

Tidal dominated deltas are preferentially developed in the mouth of rivers in the bays and strait areas of shallow seas of passive margin continental area, such as in the east of Sumatra, north of Java and east of Kalimantan areas.

Naborsaor Delta in Toba Lake Sumatra, Mahakam Delta in Eastern side of Borneo Island, and Kali Anyar Delta in northern coast of West Java Island were visited and compared to one each other for ground truth checking of the delta processes inferred from remote sensing satellite imagery interpretation.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.