The influence of the geometry of salt detachments on thrust salient development: An analogue modelling approach based on the South-Central Pyrenean thrust salient

Inspired by the structural evolution of the South-Central Pyrenean Thrust Salient we have designed an experimental program to investigate the role of the geometry of viscous detachments on the formation of thrust salients. The precontractional wedge geometry of the salt overburden facilitates propag...

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Detalles Bibliográficos
Autores: Muñoz, J. A., Ferrer García, J. Oriol (José Oriol), Gratacós Torrà, Òscar, Roca i Abella, Eduard
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2024
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/219081
Acceso en línea:https://hdl.handle.net/2445/219081
Access Level:acceso abierto
Palabra clave:Tectònica
Sedimentació
Geodinàmica
Tectònica salina
Pirineus
Tectonics
Sedimentation and deposition
Geodynamics
Sal tectonics
Pyrenees
Descripción
Sumario:Inspired by the structural evolution of the South-Central Pyrenean Thrust Salient we have designed an experimental program to investigate the role of the geometry of viscous detachments on the formation of thrust salients. The precontractional wedge geometry of the salt overburden facilitates propagation of the deformation front to the forward edge of the viscous detachment. As deformation progresses, interaction between structures formed above the viscous detachment and the adjacent frictional detachment mostly depends on the angles of the lateral edges of the weak layer with respect to the shortening direction. The orientation of the oblique structures defining thrust salients does not generally mimic the edges of the viscous detachment. They can even form at a high angle to the shortening direction if active structures in the frictional and viscous detachments connect along-strike. Thrust wedges above frictional and viscous detachments show different kinematic evolution. During the late stages of deformation frictional wedges propagate forward whereas viscous wedges deform internally by break-back thrust sequences. Both wedges show along-strike differences of the surface taper that have an impact on the evolution of the topography and related synorogenic sediment dispersal. Experimental results are consistent with the structural evolution and tectono-sedimentary relationships observed in the South-Central Pyrenees.