Método específico para la evaluación medioambiental de los lagos de origen glaciar pirenaicos y su aplicación al lago de Sabocos

This study proposes a new method to asses the environmental state of the Pyrenean glacial lakes, based on the Water Framework Directive, the concept of ecological state and inspired by widely tested and used methodologies. Starting from a good ecological state as a reference term, a series of matrices are used to identify and characterize all anthropic impacts and pressures. Information regarding the most significant ones is then compared with the criteria of a panel of experts and finally the results are summarised in ICPA matrices of Impacts, Consequences, Proposals of Corrective Measures, and Applicability. This method has been tested in the glacial lake of Sabocos, finding that its ecological quality is lower than expected, based on the identification of some severe impacts. In order to subdue them, it has been proposed a plan of correcting measures and valued its applicability.En este trabajo se propone un nuevo método para la evaluación medioambiental de los lagos pirenaicos de origen glaciar a partir de la Directiva Marco del Agua, fundamentado en el concepto de estado ecológico e inspirado en metodologías ampliamente contrastadas. Partiendo de un estado ecológico de referencia se identifican y caracterizan todas las presiones e impactos antropogénicos mediante el empleo de una serie de matrices adaptadas. Los impactos más significativos son contrastados por un panel de expertos. Finalmente, los resultados se expresan mediante matrices ICPA de Impactos, Consecuencias, Propuestas de medidas correctoras y Aplicabilidad. Este método de evaluación medioambiental se ha aplicado al lago de Sabocos. Los resultados obtenidos muestran una calidad ecológica inferior a la esperada y que algunos de los impactos identificados son severos. Con el objetivo de mitigar tales afecciones, se han propuesto una serie de medidas correctoras y evaluado su aplicabilidad

Structural and Geophysical Characterization of the Western Termination of the South Pyrenean Triangle Zone

The South Pyrenean triangle zone represents the southernmost front of the Pyrenees at its central portion deforming the Upper Eocene‐Miocene Ebro Basin deposits. Two main structures characterize its western termination, the Barbastro anticline and the San Román backthrust, which detached on the Barbastro Formation (and lateral equivalents), an Upper Eocene‐Lower Oligocene syntectonic evaporite‐rich formation that acted as a multidetachment unit. Northward, the south directed Pyrenean thrust unit (i.e., Gavarnie‐Sierras thrust sheet) detached along the Middle‐Upper Triassic evaporitic rocks to finally ramp up and glide along the same Upper Eocene‐Lower Oligocene multidetachment unit. A multidisciplinary approach allowed constructing a detailed structural and stratigraphic model of the study area. The workflow consisted of (1) constraining the geometry and structural architecture based on surface geology, interpretation of seismic lines (>900 km), and wells and (2) obtaining the 3‐D density distribution of the multidetachment unit using gravity stochastic inversion (more than 7,000 gravity stations and 1,500 density data). The geometry of the sole thrust of the Gavarnie‐Sierras thrust sheet was controlled by the distribution of the evaporite‐rich units of the Barbastro Fm. Weak detachments promoted thrust salient formation and thrust flat geometries. The western termination of the South Pyrenean triangle zone is defined as a westward transition from a ramp‐dominated and multiple triangle zone to a detachment‐dominated one. Its geometry, kinematics, and location were controlled by the heterogeneous lithology of the Barbastro Fm. and its basal, halite‐based detachment southern pinch‐out.This work was financed by the DR3AM (CGL2014‐54118‐C2‐2‐R) and E‐28(GeoApp Research Group) projects by the Spanish Ministry of Science and the Aragón Government, respectively. This work has received support from and it also aligns with methodological goals of the GeoERA project 3DGeoEU (ERANET Cofund action 731166 [H2020], Project code GeoE.171.005) and GeoPiri3D project (from the Spanish Ministry of Education and Universities, project code CGL2017‐84901‐C2‐2‐P). We acknowledge the TopoIberia project for providing the gravity data from SITOPO databases.The Academic agreement with MVE is also acknowledged. The IHS is also acknowledged for providing the Kingdom Suite software. José María Llorente and Agustín Gonzalez are here acknowledged for gravity data acquisition and processing. We also want to thank reviewers Christoph v. Hagke and Jonas Kley and Editor Laurent Jovilet for their productive suggestions and comments that helped to enrich our work and improve the manuscript.Peer reviewe