Influence of a pre-existing basement weakness on normal fault growth during oblique extension: Insights from discrete element modeling

Deng, Chao; Gawthorpe, Robert L.; Finch, Emma; Fossen, Haakon

doi:10.1016/j.jsg.2017.11.005

Cited by 58 publications

(64 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Numerical modeling, along with previous studies from the North Sea show that shear zones that strike within 45–90° of the regional extension direction, that is, close to perpendicular, and have dips greater than 30° are able to influence fault strike during rifting. Rift‐related faults often align in map view with shear zones displaying these characteristics (Bird et al, ; Deng, Gawthorpe, et al, ; Fazlikhani et al, ; Phillips et al, ). In the northern North Sea, the Åsta Fault strikes parallel to the offshore continuation of the Karmøy Shear Zone, while the Ling Depression parallels the offshore continuation of the Hardangerfjord Shear Zone (Fazlikhani et al, ; Fossen & Hurich, ; Phillips et al, ).…”

Section: Discussionmentioning

confidence: 99%

The Influence of Structural Inheritance and Multiphase Extension on Rift Development, the NorthernNorth Sea

et al. 2019

Self Cite

View full text Add to dashboard Cite

The northern North Sea rift evolved through multiple rift phases within a highly heterogeneous crystalline basement. The geometry and evolution of syn-rift depocenters during this multiphase evolution and the mechanisms and extent to which they were influenced by preexisting structural heterogeneities remain elusive, particularly at the regional scale. Using an extensive database of borehole-constrained 2D seismic reflection data, we examine how the physiography of the northern North Sea rift evolved throughout late Permian-Early Triassic (RP1) and Late Jurassic-Early Cretaceous (RP2) rift phases, and assess the influence of basement structures related to the Caledonian orogeny and subsequent Devonian extension. During RP1, the location of major depocenters, the Stord and East Shetland basins, was controlled by favorably oriented Devonian shear zones. RP2 shows a diminished influence from structural heterogeneities, activity localizes along the Viking-Sogn graben system and the East Shetland Basin, with negligible activity in the Stord Basin and Horda Platform. The Utsira High and the Devonian Lomre Shear Zone form the eastern barrier to rift activity during RP2. Toward the end of RP2, rift activity migrated northward as extension related to opening of the proto-North Atlantic becomes the dominant regional stress as rift activity in the northern North Sea decreases. Through documenting the evolving syn-rift depocenters of the northern North Sea rift, we show how structural heterogeneities and prior rift phases influence regional rift physiography and kinematics, controlling the segmentation of depocenters, as well as the locations, styles, and magnitude of fault activity and reactivation during subsequent events.

show abstract

Section: Discussionmentioning

confidence: 99%

The Influence of Structural Inheritance and Multiphase Extension on Rift Development, the NorthernNorth Sea

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…The DEM technique used in this study derives from the Lattice Solid Model (Mora & Place, , ; Place et al, ) and the Particle Dynamics Method (Finch et al, ). The technique has been extensively applied to model the dynamic evolution of geological systems (Donzé et al, ; Place et al, ), including faulting and folding processes (Deng et al, ; Finch et al, , ; Finch & Gawthorpe, ; Schöpfer et al, ); and viscous flow associated with development of boudinage structures (Abe & Urai, ) and salt diapirism (Pichel et al, ).…”

Section: Methods and Models Designmentioning

confidence: 99%

The Impact of Pre‐Salt Rift Topography on Salt Tectonics: A Discrete‐Element Modeling Approach

Pichel

Finch²,

Gawthorpe

2019

Tectonics

Self Cite

View full text Add to dashboard Cite

Gravity‐driven salt tectonics along passive margins is commonly depicted as comprising domains of updip extension and downdip contraction linked by an intermediate, broadly undeformed zone of translation. This study expands on recently published physical models using discrete‐element modeling to demonstrate how salt‐related translation over pre‐salt rift structures produce complex deformation and distribution of structural styles in translational salt provinces. Rift geometries defined by horsts and tilted fault‐blocks generate base‐salt relief affecting salt flow, diapirism and overburden deformation. Models show how flow across pairs of tilted fault‐blocks and variably‐dipping base‐salt ramps associated with pre‐salt faults and footwalls produce abrupt flux variations that result in alternation of contractional and extensional domains. Translation over tilted fault‐blocks defined by basinward‐dipping normal faults results in wide, low amplitude inflation zones above footwalls and abrupt subsidence over steep fault‐scarps, with reactive diapirs that are squeezed and extrude salt as they move over the fault. Translation over tilted‐blocks defined by landward‐dipping faults produces narrow inflation zones over steep fault‐scarps and overall greater contraction and less diapirism. As salt and cover move downdip, structures translate over different structural domains, being inverted and/or growing asymmetrically. Our models allow, for the first time, a detailed evolution of these systems in cross‐section and demonstrate the effects of variable pre‐salt relief, salt sub‐basin connectivity, width and slope of base‐salt ramps. Results are applicable to syn‐ and post‐rift salt basins; ultimately improving understanding of the effects of base‐salt relief on salt tectonics and working as a guide for interpretation of complex salt deformation.

show abstract

“…Field‐, seismic reflection‐ and modelling‐based studies indicate pre‐existing heterogeneities within crystalline (or sedimentary) rocks can influence the distribution, scale and kinematics of normal faults (e.g. Bartholomew, Peters, & Powell, ; Deng, Gawthorpe, Finch, & Fossen, ; Faccenna, Nalpas, Brun, Davy, & Bosi, ; Henza, Withjack, & Schlische, ), resulting in the formation of non‐colinear fault networks (e.g. Korme, Acocella, & Abebe, ; Morley et al, ; Reeve, Bell, Duffy, Jackson, & Sansom, ).…”

Section: Introductionmentioning

confidence: 99%

Normal fault growth influenced by basement fabrics: The importance of preferential nucleation from pre‐existing structures

et al. 2019

View full text Add to dashboard Cite

Reactivation of pre-existing intra-basement structures can influence the evolution of rift basins, yet the detailed kinematic relationship between these structures and overlying rift-related faults remains poorly understood. Understanding the kinematic as well as geometric relationship between intra-basement structures and rift-related fault networks is important, with the extension direction in many rifted provinces typically thought to lie normal to fault strike. We here investigate this problem using a borehole-constrained, 3D seismic reflection dataset from the Taranaki Basin, offshore New Zealand. Excellent imaging of intra-basement structures and a relatively weakly deformed, stratigraphically simple sedimentary cover allow us to: (a) identify a range of interaction styles between intra-basement structures and overlying, Plio-Pleistocene rift-related normal faults; and (b) examine the cover fault kinematics associated with each interaction style. Some of the normal faults parallel and are physically connected to intra-basement reflections, which are interpreted as mylonitic reverse faults formed during Mesozoic subduction and basement terrane accretion. These geometric relationships indicate pre-existing intra-basement structures locally controlled the position and attitude of Plio-Pleistocene rift-related normal faults. However, through detailed 3D kinematic analysis of selected normal faults, we show that: (a) normal faults only nucleated above intra-basement structures that experienced late Miocene compressional reactivation, (b) despite playing an important role during subsequent rifting, intra-basement structures have not been significantly extensionally reactivated, and (c) preferential nucleation and propagation of normal faults within late Miocene reverse faults and folds appears to be the key genetic relationship between contractionally reactivated intra-basement structures and rift-related normal faults. Our analysis shows that km-scale, intra-basement structures can control the nucleation and development of newly formed, rift-related nor-mal faults, most likely due to a local perturbation of the regional stress field. Because of this, simply inverting fault strike for causal extension direction may be incorrect, especially in provinces where pre-existing, intra-basement structures occur. We also 660 | EAGE COLLANEGA Et AL.

show abstract

Influence of a pre-existing basement weakness on normal fault growth during oblique extension: Insights from discrete element modeling

Cited by 58 publications

References 69 publications

The Influence of Structural Inheritance and Multiphase Extension on Rift Development, the NorthernNorth Sea

The Influence of Structural Inheritance and Multiphase Extension on Rift Development, the NorthernNorth Sea

The Impact of Pre‐Salt Rift Topography on Salt Tectonics: A Discrete‐Element Modeling Approach

Normal fault growth influenced by basement fabrics: The importance of preferential nucleation from pre‐existing structures

Contact Info

Product

Resources

About