Late Pliocene/Pleistocene Siliciclastic Influx and Resulting Burial of a Tertiary Carbonate System in the Gulf of Papua

Evgueni Tcherepanov¹, Andre Droxler¹, Philippe Lapointe², and Kenneth Mohn^3
1Rice University, Houston, TX
²Total E&P, Pau, France
³Fugro, Houston, TX

The Gulf of Papua represents one of the largest and most unique Cenozoic mixed depositional systems in the world. Currently and in the geological past, very extensive carbonate systems have interacted in space and time with huge siliciclastic influx, produced under subtropical climate by intense weathering and erosion rates of the newly formed Papua New Guinea high mountains. The timing and the geographical distribution of the siliciclastic influx were studied using a dense 2D seismic grid and a number of industrial exploration wells provided by Fugro Multi Client Services, Inc. Late Miocene to Holocene siliciclastic successions progressively infilled several deep troughs and covered either drowned or active carbonate platforms that flourished in the study area during the late Oligocene-middle Miocene. This study helps us to understand in details the spatial extent of the siliciclastic sequences, the major sediment transport pathways, and the shelf edge migration through time. It also documents the seismic expression of different types of interactions between siliciclastic sediments and drowned or active carbonate platforms, often acting as dams for prograding siliciclastics. The bulk of the siliciclastic influx by volume occurred mostly since the late Pliocene, resulting in a ~100 km southeastern progradation of the siliciclastic shelf edge during the last 3 My. This time interval corresponded to a systematic and long-term sea level fall linked to the development of major Northern Hemisphere ice sheets. In addition, the spatial distribution and transport pathways of the siliciclastic sediments were influenced by the configuration of the pre-existing carbonate system, the regional tectonic framework, and by the location of siliciclastic sediment sources.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas