The Late Quaternary Deep-Sea Depositional System in the Gulf of Papua: Linking Source, Dynamic Sedimentation Processes and Depositional Architecture

Abstract

The Gulf of Papua (GoP) is one of The US-National Science Foundation (NSF) MARGINS Source to Sink Program (S2S) focus area. This program is aimed to better understand the production, transport, and final accumulation of sediments along continental margins, particularly regarding the relative influences of tectonic, climatic, sea-level, and oceanographic processes on development of continental-margin sedimentary cover. GoP is a modern foreland basin that was formed within a continental-margin salient characterized by gradients in morphology and sediment supply, with mature rivers feeding a wide shelf margin toward the western GoP (delivering sediments to the Pandora Trough [PT]), and steep slope, small mountainous rivers and narrow shelf margin to the east, adjacent to the Papuan Peninsula(delivering sediments to the Moresby Trough [MT]); thus provide an excellent natural laboratory for analog study of the dynamic processes associated with sources, timing and depositional product in passive and active margin. The contribution of our study are three-folds: (1) The detailed stratigraphy and facies variation of the PT and MT by combining observations of sediment-core stratigraphy, accelerometer mass spectrometry (AMS) C-14 data, core x-radiographs and core thin sections. (2) The interpretation of present to near present sedimentation processes in the seafloor from acoustic and lithofacies distributions; and (3) SEM-MLA aided provenance analysis of turbidite sands. The final synthesis of our study is source-to-sink narrative extending back to ~40 kyr BP which distinguishes the processes in PT and MT. This study also offers a rare opportunity to see the evolution of regional deep-sea depositional system in higher resolution (centennial-millennial time scale, cm to m sedimentary thickness) a degree of documentation that is could not be possible in many ancient deep-sea system studies (e.g. studies in outcrop or industry-scale wireline logs and seismic data).

AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015