103 research outputs found

    Rising and falling diapirs, shifting depocenters, and flap overturning in the Cretaceous Sopeira and Sant Gervàs subbasins (Ribagorça Basin, southern Pyrenees)

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    The halokinetic structure of inverted salt-related continental margins is frequently obliterated by compressional overprinting. The Cretaceous Sopeira and Sant Gervàs subbasins of the Ribagorça Basin (south central Pyrenees) show evidence of salt-related extensional tectonics and diapiric growth along the Iberian Margin of the Mesozoic Pyrenean rift. We present an integrated field-based tectonic-sedimentary study to reconstruct the evolution of the Ribagorça Basin system previous to, and in the early stages of, the Pyrenean orogeny. The ~4km thick Albian-Cenomanian Sopeira minibasin infill thins toward the basin borders, especially toward the eastern, N-S trending, Llastarri salt weld. The 90° tilt to the south of the Sopeira basin bottom records the growth of the buried north dipping Sopeira listric fault from Albian to Santonian times, when it evolved as an extensional rollover associated with the Aulet salt roller. The ~3km thick Cenomanian-Campanian succession filling the Sant Gervàs flap displays 130° bed fanning attitude from overturned Cenomanian carbonate platform strata to upright Campanian turbidite beds. The Sant Gervàs flap development since Cenomanian times was related to the fall of a large salt pillow after the main Soperia minibasin stage. Jurassic-Campanian diachronous subsidence is also observed in the adjacent Montiberri, Faiada, and Tamurcia depocenters. Correlation with the Pedraforca, Cotiella, and Basque-Cantabrian Basins along the southern Pyrenees suggests that a significant segment of the Iberian side of the Pyrenean rift experienced a gravity-driven extension from Albian to late Santonian. The Ribagorça Basin provides an excellent field analogue for presently buried salt-related structures of extended passive margins.This research was carried out with the aid of grants by CSIC-ESF 2007–2013 JAE-Doc postdoctoral research contract (E.S.) and with funding from the Spanish Research Agency through projects CGL2009-1355, CGL2011-26670, and CGL2010-15416. Additional funding was provided by Atlas Project and Statoil Research CenterPeer reviewe

    Rising and falling diapirs, shifting depocenters and flap overturning in the Cretaceous Sopeira and Sant Gervàs subbasins (Ribagorça basin, Southern Pyrenees)

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    The halokinetic structure of inverted salt-related continental margins is frequently obliterated by compressional overprinting. The Cretaceous Sopeira and Sant Gervàs subbasins of the Ribagorça basin (South-Central Pyrenees) show evidence of salt-related extensional tectonics and diapiric growth along the Iberian margin of the Mesozoic Pyrenean rift. We present an integrated field-based tectonic-sedimentary study to reconstruct the evolution of the Ribagorça basin system previous to, and in the early stages of, the Pyrenean orogeny. The ~4 km-thick Albian-Cenomanian Sopeira minibasin infill thins towards the basin borders, especially towards the eastern N-S trending Llastarri salt weld. The 90º tilt to the south of the Sopeira basin bottom records the growth of the buried north-dipping Sopeira listric fault from Albian to Santonian times, when it evolved as an extensional rollover associated with the Aulet salt roller. The ~3 km thick Cenomanian-Campanian succession filling the Sant Gervàs flap displays 130º bed fanning attitude from overturned Cenomanian carbonate platform strata to upright Campanian turbidite beds. The Sant Gervàs flap development during Cenomanian times was related to the fall of a large salt pillow after the main Soperia minibasin stage. Jurassic-Campanian diachronous subsidence is also observed in the adjacent Montiberri, Faiada and Tamurcia depocenters. Correlation with the Pedraforca, Cotiella and Basque-Cantabrian basins along the Southern Pyrenees suggests that a significant segment of the Iberian side of the Pyrenean rift experienced a gravity-driven extension from Albian to late Santonian. The Ribagorça basin provides an excellent field analogue for presently buried salt-related structures of extended passive margins

    Conglomerats, gresos, argiles i calcàries de Montgat

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    Inventari d'espais d'interès geològic a Catalunya. Generalitat de Catalunya. Departament de Medi Ambient i Habitatge. Direcció General del Medi NaturalPostprint (published version

    Joint interpretation of magnetotelluric, seismic, and well-log data in Hontomín (Spain)

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    Acknowledgements. This work is dedicated to the memory of Andrés Pérez-Estaún, brilliant scientist, colleague, and friend. The authors sincerely thank Ian Ferguson and an anonymous reviewer for their useful comments on the manuscript. Xènia Ogaya is currently supported in the Dublin Institute for Advanced Studies by a Science Foundation Ireland grant IRECCSEM (SFI grant 12/IP/1313). Juan Alcalde is funded by NERC grant NE/M007251/1, on interpretational uncertainty. Juanjo Ledo, Pilar Queralt and Alex Marcuello thank Ministerio de Economía y Competitividad and EU Feder Funds through grant CGL2014- 54118-C2-1-R. Funding for this Project has been partially provided by the Spanish Ministry of Industry, Tourism and Trade, through the CIUDEN-CSIC-Inst. Jaume Almera agreement (ALM-09-027: Characterization, Development and Validation of Seismic Techniques applied to CO2 Geological Storage Sites), the CIUDEN-Fundació Bosch i Gimpera agreement (ALM-09-009 Development and Adaptation of Electromagnetic techniques: Characterisation of Storage Sites) and the project PIERCO2 (Progress In Electromagnetic Research for CO2 geological reservoirs CGL2009-07604). The CIUDEN project is co-financed by the European Union through the Technological Development Plant of Compostilla OXYCFB300 Project (European Energy Programme for Recovery).Peer reviewedPublisher PD

    3-D lithospheric structure and regional/residual Bouguer anomalies in the Arabia-Eurasia collision (Iran)

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    The aim of this work is to propose a first-order estimate of the crustal and lithospheric mantle geometry of the Arabia-Eurasia collision zone and to separate the measured Bouguer anomaly into its regional and local components. The crustal and lithospheric mantle structure is calculated from the geoid height and elevation data combined with thermal analysis. Our results show that Moho depth varies from ~42 km at the Mesopotamian-Persian Gulf foreland basin to ~60 km below the High Zagros. The lithosphere is thicker beneath the foreland basin (~200 km) and thinner underneath the High Zagros and Central Iran (~140 km). Most of this lithospheric mantle thinning is accommodated under the Zagros mountain belt coinciding with the suture between two different mantle domains on the Sanandaj-Sirjan Zone. The regional gravity field is obtained by calculating the gravimetric response of the 3-D crustal and lithospheric mantle structure obtained by combining elevation and geoid data. The calculated regional Bouguer anomaly differs noticeably from those obtained by filtering or just isostatic methods. The residual gravity anomaly, obtained by subtraction of the regional components to the measured field, is analyzed in terms of the dominating upper crustal structures. Deep basins and areas with salt deposits are characterized by negative values (~-20 mGal), whereas the positive values are related to igneous and ophiolite complexes and shallow basement depths (~20 mGal). © 2012 The Authors Geophysical Journal International © 2012 RAS.This research has been partly funded by ProjectsATIZA (CGL2009-09662-BTE) and TECLA (CGL2011–26670) and consolider-Ingenio 2010 Topo-Iberia (CSD2006-00041).Peer Reviewe

    Jurassic rifting to post-rift subsidence analysis in the Central High Atlas and its relation to salt diapirism

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    et. al.The subsidence evolution of the Tethyan Moroccan Atlas Basin, presently inverted as the Central High Atlas, is characterized by an Early Jurassic rifting episode, synchronous with salt diapirism of the Triassic evaporite-bearing rocks. Two contrasting regions of the rift basin – with and without salt diapirism – are examined to assess the effect of salt tectonics in the evolution of subsidence patterns and stratigraphy. The Djebel Bou Dahar platform to basin system, located in the southern margin of the Atlas Basin, shows a Lower Jurassic record of normal faulting and lacks any evidence of salt diapirism. In contrast, the Tazoult ridge and adjacent Amezraï basin, located in the centre of the Atlas Basin, reveals spectacular Early Jurassic diapirism. In addition, we analyse alternative Central High Atlas post-Middle Jurassic geohistories based on new thermal and burial models (GENEX® 4.0.3 software), constrained by new vitrinite reflectance data from the Amezraï basin. The comparison of the new subsidence curves from the studied areas with published subsidence curves from the Moroccan Atlas, the Saharan Atlas (Algeria) and Tunisian Atlas show that fast subsidence peaks were diachronous along the strike, being younger towards the east from Early–Middle Jurassic to Late Cretaceous. This analysis also evidences a close relationship between these high subsidence rate episodes and salt diapirism.This study was part of a collaborative research project funded by Statoil Research Centre, Bergen (Norway) and by the CSIC-FSE 2007-2013 JAE-Doc post-doctoral research contract (E.S.). The Spanish Ministry of Education and Science provided additional funding (MEC) through the projects Intramural Especial (CSIC 201330E030) and MITE (CGL 2014-59516). This research was supported by the Grup Consolidat de Recerca “Geologia Sediment aria” de la Generalitat de Catalunya (2014GSR251).Peer reviewedPreprin

    Basement structure of the Hontomín CO2 storage site (Spain) determined by integration of microgravity and 3-D seismic data

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    A multidisciplinary study has been carried out in Hontomín (Spain) to determine the basement structural setting, its geometry and the geometry of the sedimentary succession of an area aimed to be the first Spanish pilot plant for CO2 storage. An integration of coincident 3-D seismic results, borehole data and unpublished microgravity data were used to reproduce the deep structure and topography of the basement and to quantify the thickness of the Triassic Keuper evaporites. The subsurface structure is characterized by a half-graben setting filled with Keuper evaporites (up to 2000m thick), forming an extensional forced fold. All data sets clearly identify two main fault systems, compartmentalizing the main structural domain into three differentiated blocks. These faults have been interpreted to be reactivated normal faults that have led to the formation of the Hontomín dome. © Author(s) 2016.The data sets in this work have been funded by Fundación Ciudad de la Energía (Spanish Government, www.ciuden.es) and by the European Union through the “European Energy Programme for Recovery” and the Compostilla OXYCFB300 project. Juan Alcalde is currently funded by NERC grant NE/M007251/1.Peer reviewe

    Crustal-scale cross-sections across the NW Zagros belt: Implications for the Arabian margin reconstruction

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    Quantified balanced and restored crustal cross-sections across the NW Zagros Mountains are presented in this work integrating geological and geophysical local and global datasets. The balanced crustal cross-section reproduces the surficial folding and thrusting of the thick cover succession, including the near top of the Sarvak Formation (∼90 Ma) that forms the top of the restored crustal cross-section. The base of the Arabian crust in the balanced cross-section is constrained by recently published seismic receiver function results showing a deepening of the Moho from 42 ± 2 km in the undeformed foreland basin to 56 ± 2 km beneath the High Zagros. The internal parts of the deformed crustal cross-section are constrained by new seismic tomographic sections imaging a ∼50° NE-dipping sharp contact between the Arabian and Iranian crusts. These surfaces bound an area of 10800 km2 that should be kept constant during the Zagros orogeny. The Arabian crustal cross-section is restored using six different tectonosedimentary domains according to their sedimentary facies and palaeobathymetries, and assuming Airy isostasy and area conservation. While the two southwestern domains were directly determined from well-constrained surface data, the reconstruction of the distal domains to the NE was made using the recent margin model of Wrobel-Daveau et al. (2010) and fitting the total area calculated in the balanced cross-section. The Arabian continental-oceanic boundary, at the time corresponding to the near top of the Sarvak Formation, is located 169 km to the NE of the trace of the Main Recent Fault. Shortening is estimated at ∼180 km for the cover rocks and ∼149 km for the Arabian basement, including all compressional events from Late Cretaceous to Recent time, with an average shortening rate of ∼2 mm yr-1 for the last 90 Ma. © 2011 Cambridge University Press.We thank the following projects for their additional support: DARIUS Programme and its sponsors, TopoMed CGL2008– 03474-E/BTE, ESF-Eurocores 07-TOPOEUROPE-FP006, TopoAtlas (CGL2006–05493/BTE), ATIZA (CGL2009– 09662-BTE) and Consolider-Ingenio 2010 Topo-Iberia (CSD2006–00041).Peer Reviewe

    La Directiva Europea sobre el Horario de Trabajo y su impacto sobre la formación quirúrgica. Resultados de una encuesta entre los residentes de Cirugía Cardiovascular en España

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    ObjetivosLa Directiva Europea del Horario de Trabajo (European Working time Directive [EWTD]) de 1993 debería estar en funcionamiento para cirujanos cardiovasculares y residentes en agosto de 2009, como respuesta a las dudas sobre la calidad del cuidado del paciente y la calidad de vida de los profesionales causadas por el trabajo excesivo y la fatiga laboral. Hay temor al impacto negativo de la fatiga en la calidad de la atención al paciente y de las residencias quirúrgicas, en especial en Cirugía Cardiovascular. Evaluamos el nivel de conocimiento de los residentes españoles sobre la EWTD.MétodosEncuesta individual a los residentes asistentes al XIII Curso de Residentes de la Sociedad Española de Cirugía Torácica y Cardiovascular de mayo de 2008. Incluye un resumen de los objetivos principales de la EWTD.ResultadosAsistieron 58 de 70 residentes posibles. La encuesta fue completada por 26. El 92,3% no había leído la EWTD y el 26,9% no tenía el mínimo conocimiento. El 54,2% estaba de acuerdo con su contenido; 53,8% la considera incompatible con su modelo ideal de formación; 68% cree que tendrá impacto negativo en la misma; 87% cree que discrimina a los residentes quirúrgicos; 65,2% cree que reducirá sus ingresos anuales; 84,6% cree que parte de la plantilla de sus servicios se opondrá.ConclusionesExiste un desconocimiento muy importante sobre la EWTD por los residentes españoles de Cirugía Cardiovascular. Sorprendentemente, la mayoría está de acuerdo con la EWTD a pesar de que pueda tener impacto negativo en su formación y retribución económica. Se requiere una profunda reflexión por parte de las sociedades profesionales sobre este tema para promover y proteger la formación en nuestra especialidad.ObjectivesThe 1993 European Working Time Directive (EWTD) should be implemented to its entirety for cardiovascular surgeons and residents by August 2009 as an answer to the concern about patient care and quality of life of professionals caused by fatigue and excessive continuous work. Great concern rose regarding its negative impact in the quality of surgical residencies, specifically in cardiovascular surgery. Our objective was to assess the knowledge of Spanish Cardiovascular Surgery residents on the EWTD and their level of agreement with its content.MethodsA survey questionnaire was given to all residents attending the XIII Annual Course organized by the Spanish Society of Thoracic-Cardiovascular Surgery in May 2008. It included a brief summary of the key features of the EWTD.ResultsOut of 70 eligible residents, 58 attended. Of these, 26 completed and returned the survey. 92,3% never read and 26,9% knew absolutely nothing about the EWTD. 54,2% agreedwith its content; 53,8% think it is not compatible with their ideal training model; 68% believe it will have a negative impact on their training; 87% think it negatively discriminates surgical residents; 65,2% believe it will decrease their annual stipends; 84,6% think it will find the opposition of part of the staff in their respective departments.ConclusionsKnowledge about the contents of the EWTD among Spanish Cardiovascular Surgery residents is scarce. The majority of them agree with the EWTD even realizing it may have a negative impact on training quality and economic retribution. A deep reflection on this by national and European societies to protect and promote the quality of the training in our specialty is required

    The impact of syn- and post-extension prograding sedimentation on the development of salt-related rift basins and their inversion: Clues from analogue modelling

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    Various studies have demonstrated the intrinsic interrelationship between tectonics and sedimentation in salt-related rift basins during extension as well as during their inversion by compression. Here, we present seven brittle-ductile analogue models to show that the longitudinal or transverse progradation of sediment filling an elongate extensional basin has a substantial impact on the growth of diapirs and their lateral geometrical variations. We use five extensional models to reveal how these prograding systems triggered diapir growth variations, from proximal to distal areas, relative to the sedimentary source. In the models, continuous passive diapir walls developed, after a short period of reactive-active diapiric activity, during syn-extensional homogeneous deposition. In contrast, non-rectilinear diapir walls grew during longitudinal prograding sedimentation. Both longitudinal and transverse post extensional progradation triggered well-developed passive diapirs in the proximal domains, whereas incipient reactive-active diapirs, incipient roller-like diapirs, or poorly developed diapirs were generated in the distal domains, depending on the modelled sedimentary pattern. Two models included final phases of 6% and 10% shortening associated with basin inversion by compression, respectively, to discriminate compressional from purely extensional geometries. With the applied shortening, the outward flanks of existing diapir walls steepened their dips from 8 degrees-17 degrees to 30 degrees-50 degrees. Likewise, 6% of shortening narrowed the diapir walls by 32%-72%, with their fully closing (salt welds) with 10% of shortening. We compare our results with the distribution of salt walls and minibasins of the Central High Atlas diapiric basin in Morocco, which was infilled with a longitudinally prograding mixed siliciclastic and carbonatic depositional sequence during the Early-Middle Jurassic with a minimum thicknesses of 2.5-4.0 km. (C) 2017 Elsevier Ltd. All rights reserved
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