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Interactions Between Continental Breakup Dynamics and Large-scale Delta Systems Evolution: Insights from the Cretaceous Ceduna Delta System, Bight Basin, Southern Australian margin

Created 16/10/2025

Updated 16/10/2025

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The interpretation of two regional seismic reflection profiles and the construction of a balanced cross section through the southern Australian margin (Bight Basin) are designed to analyze the influence of the Australia-Antarctica continental breakup process on the kinematic evolution of the Cretaceous Ceduna delta system. The data shows that the structural architecture of this delta system consists of two stacked sub-delta systems. The lower White Pointer delta system (Late Albian-Santonian) is an unstable tectonic wedge, regionally detached seaward above Late Albian ductile shales. Sequential restorations suggest that the overall gravitational sliding behavior of the White Pointer delta wedge (~45 km of seaward extension, i.e., ~25%) is partially balanced by the tectonic denudation of the subcontinental mantle. We are able to estimate the horizontal stretching rate of the mantle exhumation between ~2 km Ma-1and 5 km Ma-1. The associated uplift of the distal part of the margin and associated flexural subsidence in the proximal part of the basin are partially responsible for the decrease of the gravitational sliding of the White Pointer delta system. Lithospheric failure occurs at ~84 Ma through the rapid exhumation of the mantle. The upper Hammerhead delta system (Late Santonian-Maastrichtian) forms a stable tectonic wedge developed during initial, slow seafloor spreading and sag basin evolution of the Australian side margin. Lateral variation of basin slope (related to the geometry of the underlying White Pointer delta wedge) is associated with distal raft tectonic structures sustained by high sedimentation rates. Finally, we propose a conceptual low-angle detachment fault model for the evolution of the Australian-Antarctica conjugate margins, in which the Antarctica margin corresponds to the upper plate and the Australian margin to the lower plate.

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Title Interactions Between Continental Breakup Dynamics and Large-scale Delta Systems Evolution: Insights from the Cretaceous Ceduna Delta System, Bight Basin, Southern Australian margin
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/03b08719-a599-4c8c-8e87-a9e23e177049
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 22/04/2018
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
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        123.75,
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      ],
      [
        138.25,
        -39.0
      ],
      [
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      ],
      [
        123.75,
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      ],
      [
        123.75,
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      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Interactions Between Continental Breakup Dynamics and Large-scale Delta Systems Evolution: Insights from the Cretaceous Ceduna Delta System, Bight Basin, Southern Australian margin". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/interactions-between-continental-breakup-dynamics-and-large-scale-delta-systems-evolution-insig