Mechanics of fault and expulsion rollover systems developed on passive margins detached on salt; insights from analogue modelling and optical strain monitoring

Csaba Krezsek, Jurgen Adam, Djordje Grujic

Research output: Contribution to journalArticlepeer-review


Scaled analogue experiments with layered brittle and ductile materials have been used to simulate the development of listric growth-fault and expulsion rollover systems during gravitational spreading of a passive margin sedimentary wedge detached on salt. The experiments were performed with varying sedimentation patterns and rates to simulate different depositional scenarios. Deformation monitoring with 3D optical image correlation techniques was used to quantify the 3D surface evolution and strain history of model structures. Our results indicate that rollover structure kinematics is strongly coupled to sedimentation patterns and rates. Whereas differential loading governs the margin-scale state of stress and extensional spreading in the experiments, more localized feedback between the dynamic depositional systems, fault-controlled subsidence, and salt mobilization control the strain history of local fault structures. This is reflected in the characteristic succession of extensional structures that evolve from symmetrical grabens through early, mature and late (collapsed) basinward listric growth-fault and rollover systems into landward listric growth-fault and rollover systems. A lack of sedimentation enhances reactive diapir rise and passive diapirism, whereas low sedimentation rates favour development of long-lived basinward listric growth-fault or expulsion rollover systems. Conversely, high sedimentation rates lead to the development of landward listric growth-fault and rollover systems.
Original languageEnglish
Pages (from-to)103-121
JournalGeological Society of London Special Publication
Publication statusPublished - 2007


  • basin analysis diapirs faults grabens kinematics listric faults mechanics natural analogs passive margins petroleum petroleum exploration plate tectonics rates salt tectonics strain structural controls structural traps systems tectonics three-dimensional models traps

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