Abstract
This study presents a structural analysis and Mesozic tectonostratigraphic history for the
Dampier Sub-basin, located in the Northern Carnarvon Basin on the North-West Shelf of
Australia. Regional unconformities, seismic stratigraphic packages and rift-related
extensional structures were interpreted from the Demeter 3D seismic survey, integrated with
biostratigraphic ages and lithostratigraphy from exploration well data. Structural analysis
identified four populations of Triassic-aged syn-rift extensional faults; (1) NNE-striking
basin-oblique faults comprising the NE-oriented Rankin Trend, (2) NE-striking basinparallel
faults comprising the Madeleine Trend, (3) southern NE-striking sinuous basinparallel
faults, and (4) N/S-striking oblique-normal faults. A 3D fault model was produced
that reveals the syn-rift topography of the sub-basin in the Mesozoic. Fault orientations and
geometries indicate coeval evolution of the Mesozoic basin fault architecture, driven by
WNW-oriented oblique extension focused on reactivated Paleozoic rift structures. All fault
populations are linked to form a greater fault system accommodating extensional strain
across the basin. Six seismic stratigraphic packages were interpreted, separated by regional
unconformities. These packages correspond to changes in relative sea level, sedimentation
rates and accommodation associated with the progressive breakup of Gondwana and allow
correlation of basin-scale events to plate-scale tectonic events. Five phases of Mesozoic
rifting were distinguished; (1) Triassic pre-rift thermal subsidence and sedimentation, (2)
Upper Triassic rifting establishing the structural architecture of the sub-basin, forming the
Lewis and Kendrew Troughs, Rankin Platform and Madeleine Trend, (3) Upper Jurassic to
Lower Cretaceous rifting following a major erosional event, punctuated by minor inversion,
(4) Cretaceous post-rift thermal sag and conformable sedimentation of dominantly carbonate
successions, (5) Cenozoic passive margin settling with prograding carbonate sedimentation.
Dampier Sub-basin, located in the Northern Carnarvon Basin on the North-West Shelf of
Australia. Regional unconformities, seismic stratigraphic packages and rift-related
extensional structures were interpreted from the Demeter 3D seismic survey, integrated with
biostratigraphic ages and lithostratigraphy from exploration well data. Structural analysis
identified four populations of Triassic-aged syn-rift extensional faults; (1) NNE-striking
basin-oblique faults comprising the NE-oriented Rankin Trend, (2) NE-striking basinparallel
faults comprising the Madeleine Trend, (3) southern NE-striking sinuous basinparallel
faults, and (4) N/S-striking oblique-normal faults. A 3D fault model was produced
that reveals the syn-rift topography of the sub-basin in the Mesozoic. Fault orientations and
geometries indicate coeval evolution of the Mesozoic basin fault architecture, driven by
WNW-oriented oblique extension focused on reactivated Paleozoic rift structures. All fault
populations are linked to form a greater fault system accommodating extensional strain
across the basin. Six seismic stratigraphic packages were interpreted, separated by regional
unconformities. These packages correspond to changes in relative sea level, sedimentation
rates and accommodation associated with the progressive breakup of Gondwana and allow
correlation of basin-scale events to plate-scale tectonic events. Five phases of Mesozoic
rifting were distinguished; (1) Triassic pre-rift thermal subsidence and sedimentation, (2)
Upper Triassic rifting establishing the structural architecture of the sub-basin, forming the
Lewis and Kendrew Troughs, Rankin Platform and Madeleine Trend, (3) Upper Jurassic to
Lower Cretaceous rifting following a major erosional event, punctuated by minor inversion,
(4) Cretaceous post-rift thermal sag and conformable sedimentation of dominantly carbonate
successions, (5) Cenozoic passive margin settling with prograding carbonate sedimentation.
| Original language | English |
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| Qualification | Masters |
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| Publication status | Unpublished - 2016 |