Passive Margins: Tectonics, Sedimentation and Magmatism
CONTAINS OPEN ACCESS

This volume has evolved from papers written in memory of Professor David Roberts. They summarize the key findings of recent research on passive margins, from tectonics, bathymetry, stratigraphy and sedimentation, structural evolution and magmatism. Papers include analyses of the central and southern Atlantic margins of South America and Africa, papers on magmatism and extension in the NE Brazilian margin and on the Cote de Ivoire margin, rift architectures of the NW Red Sea margin, tectonics of the eastern Mediterranean margin, salt tectonics of passive margins of the Gulf of Mexico and Brazil, and papers on the NW Shelf margin of Australia. The volume provides readers with new insights into the complexities of passive margin systems that are in reality, not so passive.
Fault-scarp degradation in the central Exmouth Plateau, North West Shelf, Australia Available to Purchase
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Published:May 09, 2020
Abstract
Latest Triassic–earliest Late Jurassic domino-style extensional faulting in the central Exmouth Plateau, North West Shelf of Australia, exhibits footwall degradation scarps with up to 1.8 km of scarp retreat of the Upper Triassic Mungaroo Formation. Extensional fault-propagation folding, rotation and uplift produced gravitationally driven scarp collapse of the incompetent and mudstone-dominated uppermost Mungaroo Formation. Scarp degradation occurred along the entire extent of the footwalls of three major faults within the research area. Individual segments display listric fault surfaces in cross-section and scoop-shaped scars in three dimensions. The listric collapse faults dip towards the erosional scarp and sole out at different levels within the upper Triassic Mungaroo Formation.
Footwall crestal collapse formed coalesced, scoop-shaped degradation scarps with Mungaroo Formation debris deposited as wedges within the adjacent hanging-wall synclines. Maximum scarp degradation occurred at the fault centres and decreased towards the fault tips. This study proposes new three-dimensional evolutionary structural models for the fault-scarp degradation in the central Exmouth Plateau.
- Australasia
- Australia
- Carnarvon Basin
- clastic rocks
- debris
- degradation
- deposition
- erosion
- erosion features
- Exmouth Plateau
- extension faults
- extension tectonics
- fault scarps
- faults
- geophysical methods
- geophysical surveys
- Indian Ocean
- lithostratigraphy
- Mesozoic
- mudstone
- North West Shelf
- petroleum
- petroleum exploration
- sedimentary rocks
- seismic methods
- surveys
- systems
- tectonics
- Triassic
- Upper Triassic
- Western Australia
- Mungaroo Formation