Reflexiones en Torno a la Divulgación del Obra Cinematográfica

Reflexiones en Torno a la Divulgación del Obra Cinematográfic

La propiedad intelectual e Internet: su subordinación a la cultura y a la información

La propiedad intelectual e Internet: su subordinación a la cultura y a la información

Interplay between tectonics, climate and fluvial transport during the Cenozoic evolution of the Ebro Basin (NE Iberia).

Three-dimensional modeling that integrates fluvial sediment transport, crustal-scale tectonic deformation, and lithospheric flexural subsidence is carried out to simulate the landscape and drainage evolution of the Ebro sedimentary basin (NE Iberia). The Ebro Basin underwent a long period of closed intramountain drainage as a result of tectonic topography generation at the Pyrenees, the Iberian Range, and the Catalan Coastal Range. In the late Oligocene, the Catalan Coastal Range underwent extension leading to the formation of the Valencia Trough (NW Mediterranean), but the Ebro Basin remained closed for nearly 15 Myr more before the Ebro River cut through the remnants of the topographic barrier. This drainage opening caused widespread basin incision that shaped spectacular outcrops of the syntectonic and posttectonic infill. Here we investigate the processes controlling these major drainage changes. The modeling results, constrained by a large data set on the tectonic and transport evolution of the area, predict a closed phase characterized by a large lake in the central eastern Ebro Basin. Dry climatic conditions probably lowered the lake level and contributed, together with rift flank uplift, to prolong this endorheic basin stage. The age and amount of reworked sediment after the opening are consistent with an onset of basin incision between 13 and 8.5 Ma as a result of lake capture by escarpment erosion and lake level rise associated with sediment accumulation and wetter climatic conditions. Sea level changes in the Mediterranean had no major impact in the large-scale drainage evolution of the Ebro Basin.This work has been funded by the Netherlands Center for Integrated Solid Earth Science (ISES)

Extreme Mesozoic Crustal Thinning in the Eastern Iberia Margin: The Example of the Columbrets Basin (Valencia Trough)

International audienceEastern 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