--> --> 3D Seismic Analysis of the Structural Evolution of the Ceduna Sub-Basin, Great Australian Bight
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3D Seismic Analysis of the Structural Evolution of the Ceduna Sub-Basin, Great Australian Bight

Abstract

We use three-dimensional (3D) seismic reflection data to determine a suitable growth model of four hard-linked normal Previous HitfaultNext Hit assemblages, at the extensional top of a gravitationally driven delta system in the central Ceduna Sub-basin, Australia. The Previous HitfaultNext Hit array we present soles out at a detachment surface at the base of a marine mud of late Albian age. Strike linked Previous HitfaultNext Hit assemblages are oriented NW-SE, with all faults dip-linked through the Santonian interval, joining upper post-Santonian normal Previous HitfaultNext Hit segments to lower Cenomanian-Santonian listric Previous HitfaultNext Hit segments. Kilometre-scale Cenomanian-Santonian displacement of listric Previous HitfaultNext Hit segments defines an underlying structural grain, which has likely reactivated, nucleating the post-Santonian Previous HitfaultNext Hit segments, which mimic the underlying Previous HitfaultNext Hit plane geometry. Through simplistic depth conversion a Previous HitfaultNext Hit plane model has been created from Previous HitfaultNext Hit plane dip measurements, which calculates Previous HitfaultNext Hit plane dip slip displacement from vertical throw measurements. This is necessary to measure Cenomanian nucleation and growth at the base of a listric Previous HitfaultNext Hit plane decreasing in dip angle with depth. To examine normal Previous HitfaultNext Hit growth, we have used displacement-distance, displacement-depth and expansion index analysis to identify synkinematic strata. Our analysis shows that Cenomanian-Santonian Previous HitfaultNext Hit growth is in accordance with the isolated Previous HitfaultNext Hit model and that post-Santonian Previous HitfaultNext Hit growth is in accordance with both the isolated Previous HitfaultNext Hit model and the segmented coherent Previous HitfaultNext Hit model. This indicates that these Previous HitfaultNext Hit growth models need not be mutually exclusive to the growth of vertically and laterally segmented Previous HitfaultTop systems.