AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
The Tarera-Aiduna Strike-Slip Fault Zone and Its Impact on Deepwater Channels Offshore West Papua, Indonesia
(1) Department of Earth Science and Engineering, Imperial College London, London, United Kingdom.
(2) Niko Asia Ltd, Jakarta, Indonesia.
The interaction between structures and deepwater channel systems within a sinistral, transtensional strike-slip system offshore West Papua, Indonesia is described using recently acquired, exceptional quality, bathymetry data. The Kumawa study area, offshore West Papua, is located at the tip of a distributed triple junction in one of the most tectonically complex regions of the world with thrusting, strike-slip movement and normal faulting all active within the area. Rapid transitions in channel geometry occur frequently within the area and along individual deepwater channels as the systems respond to uplift and subsidence caused by interactions between folding, faulting and mud volcano activity.
The innovative use of high quality bathymetry and backscatter data alongside more conventional 2D seismic data allows new insights into deepwater sedimentary systems. A distinction is made between open and closed systems; open systems defined as those where sedimentary processes outpace structural deformation and closed systems where structural growth exceeds sediment deposition and erosion rates. Detailed observations of these systems result in several sub-divisions being proposed. Within open systems four main interactions are defined; deflection, backstepping, confinement and blocking. In closed systems three main classifications are defined; subsidence induced, uplift induced and channel ponding. These interactions can occur in combination, but each has a unique set of characteristics identifiable from surface and subsurface features. Variations in morphological parameters such as channel widths and depths can be used alongside detailed observations to define these processes.
Outstanding images of the structural and depositional systems generated by bathymetry data provide a unique insight into the interactions between these processes in an active transtensional strike-slip setting, allowing the categorisation and visualisation of previously undocumented processes.