Tectònica salina a la zona sudpirinenca central: estudi integrat de tectonostratigrafia i modelització numèrica
- Autores: Laura Burrel Garcia
- Directores de la Tesis: Antonio Teixell Cacharo (dir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2020
- Idioma: español
- ISBN: 9788449094637
- Tribunal Calificador de la Tesis: Frank Peel Frank (presid.), Josep Anton Muñoz i de la Fuente (secret.), Jean-Paul Callot Jean Paul (voc.)
- Programa de doctorado: Programa de Doctorado en Geología por la Universidad Autónoma de Barcelona
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The Triassic Keuper evaporites have long been recognized as the main detachment level of the Pyrenean foreland thrust belts and basins. The Cretaceous to Oligocene deformation of the forelands presents evidences of diapirism, comparatively less studied due to the most visible imprint of thrust and fault-related folds.
This thesis presents a multidisciplinary study that explores the role of salt in the tectonic style of two classical areas of the southern Pyrenees, as are 1) the Montsec and Serres Marginals, and 2) the northern margin of the Organyà basin and the adjacent Nogueres Zone. The study which emphasizes the role of halokinesis in the structural and sedimentary evolution of the central-southern Pyrenees. Addressing the role of salt diapirism during the orogeny provides new interpretations with strong implications for the kinematics of compressional deformation and the amount of orogenic shortening.
In the Serres Marginals, early salt structures developed during the Mesozoic pre-compressional stage into a system of diapirs, anticlines and intervening synclines that were filled. During the Pyrenean compressive stage, the folding mechanisms evolved from predominantly vertical (bending) movements triggered by the sedimentary loading to buckling by horizontal forces. The unroofing of the crests of the structure enhanced salt withdrawal, leading to primary and secondary welding and subsequent syncline imbrication. In the north margin of the Organyà basin, salt migration enabled the northward tilting of the basin during the Eocene and Oligocene, which is reflected in the progressive unconformity and onlap of the La Pobla and Gurp intramontane basins. At the same time, sedimentary load accelerated salt migration, enabling the rotation and overturning of the unrooted leading edge of the Nogueres thrust sheet (têtes plongeantes) into the Keuper evaporites.
From the field case studies and numerical modelling, this thesis explores essential questions on salt tectonics, regarding the transition from load-induced bending to compressional buckling, the role of syn-compressional sedimentation and erosion or the effect of pre-existing diapir structures in the structural development of foreland basins.
