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

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)

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

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)

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)

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

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

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

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

Dinámica, Factores condicionantes y posibles causas de la formación de la tartera de Cambrils (Solsonès, Lleida)

Landslides and rockfalls are a common hazard in mountain areas like the Pyrenees. However, due to the difficulty of access and therefore of data acquisition, and the low density of population they are poorly studied. The Tartera de Cambrils, is located in a small town in the Solsonès region, Catalonia, and is the product of ancient landslides and succeeding rockfalls. These processes can endanger different infrastructures in the village of Cambrils such as the road, the sports centre, the salt flats called 'El Salí' (currently also being used for tourist activity), two inns and several houses. This study aims to determine the processes that caused the initial landslides, those that occur at the rock slope nowadays and their causative factors. For this, we compiled information from the literature, conducted a field study building a geologic and geomorphologic cartography and acquired LiDAR data, with a Terrestrial Laser Scan, and photographs in order to produce three-dimensional point clouds. We also analyse the rock-cliff stability using photogrammetry and LiDAR data and direct measures of rock mass discontinuities. The bedding dips smoothly and contrary to the slope, making planar sliding an unprovable mechanism, favouring wedge sliding and toppling. The rock discontinuities are the main causative factor of rockfalls. Rockfall originates from rock fronts of decametric volume along the main scarp and on the scree. These rock fronts rotated respect to the rock in situ. The farther away from the main scarp, the larger the rotation of the blocks. The analysis of the fractures allows estimating an important possibility of rockfall directly affecting the inns and the road and provides fundamental data for the development of protection measures

Basement structure of the Hontomín CO2 Geological storage facility (Burgos, Spain): integration of microgravity & 3D seismic reflection data

The structure of the Hontomín CO2 geological storage research facility has been addressed combining 3D seismic reflection data, borehole information and microgravity data. The integrated interpretation constrains the basement structural setting geometry and that of the sedimentary succession. The study unravels the deep structure and topography of the basement and quantifies the thickness of the Triassic Keuper evaporites. We describe a half-graben setting filled with Keuper evaporites (up to 2000 m) forming an extensional forced fold. Three set of faults are identified with two main fault systems compartmentalizing the area into three differentiated blocks. These faults have been interpreted to be reactivated normal faults that have led to the formation of the Hontomín dome.The datasets 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. Dr. Juan Alcalde is currently funded by NERC grant NE/M007251/1.Peer Reviewe