Extreme Mesozoic crustal thinning in the Eastern Iberia margin: The example of the Columbrets Basin (Valencia Trough)

Eastern Iberia preserves a complex succession of Mesozoic rifts partly or completely inverted during the Late Cretaceous and Cenozoic in relation with Africa-Eurasia convergence. Notably, the Valencia Trough, classically viewed as part of the Cenozoic West Mediterranean basins, preserves in its sout...

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Bibliographic Details
Authors: Etheve, Nathalie, Mohn, Geoffroy, de lamotte, Dominique Frizon, Roca i Abella, Eduard, Tugend, Julie, Gómez-Romeu, Júlia
Format: article
Status:Published version
Publication Date:2018
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/183537
Online Access:https://hdl.handle.net/2445/183537
Access Level:Open access
Keyword:Tectònica salina
Geologia estructural
Columbrets (País Valencià)
Tectonique du sel
Structural geology
Columbretes Islands (Valencian Community)
Description
Summary:Eastern Iberia preserves a complex succession of Mesozoic rifts partly or completely inverted during the Late Cretaceous and Cenozoic in relation with Africa-Eurasia convergence. Notably, the Valencia Trough, classically viewed as part of the Cenozoic West Mediterranean basins, preserves in its southwestern part a thick Mesozoic succession (locally ≈10 km thick) over a highly thinned continental basement (locally only ≈3.5 km thick). This subbasin, referred to as the Columbrets Basin, represents a Late Jurassic-Early Cretaceous hyperextended rift basin weakly overprinted by subsequent events. Its initial configuration is well preserved allowing us to unravel its 3-D architecture and tectonostratigraphic evolution in the frame of the Mesozoic evolution of eastern Iberia. The Columbrets Basin benefits from an extensive data set combining high-resolution seismic reflection profiles, drill holes, seismic refraction data, and expanding spread profiles. The interactions between halokinesis, involving the Upper Triassic salt, and extensional deformation controlled the architecture of the Mesozoic basin. The thick uppermost Triassic to Cretaceous succession displays a large-scale 'syncline' shape, progressively stretched and dismembered toward the basin borders. We propose that the SE border of the basin is characterized by a large extensional detachment fault acting at crustal scale and interacting locally with the Upper Triassic décollement. This extensional structure accommodates the exhumation of the continental basement and part of the crustal thinning. Eventually, our results highlight the complex interaction between extreme crustal thinning and occurrence of a prerift salt level for the deformation style and tectonostratigraphic evolution of hyperextended rift basins.