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This article presents a morpho-structural map at 1:50,000 scale of the confluence area between three regional units: (1) the Burgalesa Platform (Mesozoic; Cantabrian Mountains), (2) the Duero Basin and (3) the Ebro Basin (Cenozoic foreland basins). The map covers an area of 527 km2 in north Iberia. Additionally, structural lineaments such as joints are well preserved and documented in the Upper Cretaceous sediments of the Burgalesa Platform, represented by four main sets regarding their orientation. The foreland basins are incised in Miocene materials by rivers that have developed a complex drainage system controlling the deposition of the most recent alluvial sediments, following the four structural orientations. The map, together with the analysis of orthophotos and a Digital Terrain Model, and outcrop-scale observations, have led us to document the influence of the Miocene to present-day compression and strike-slip tectonic regime on the configuration of the drainage system and the geomorphological features.

One of the concerns of underground CO2 onshore storage is the triggering of induced seismicity and fault reactivation by the pore pressure increasing. Hence, a comprehensive analysis of the tectonic parameters involved in the storage rock formation is mandatory for safety management operations. Unquestionably, active faults and seal faults depicting the storage bulk are relevant parameters to be considered. However, there is a lack of analysis of the active tectonic strain field affecting these faults during the CO2 storage monitoring. The advantage of reconstructing the tectonic field is the possibility to determine the strain trajectories and describing the fault patterns affecting the reservoir rock. In this work, we adapt a methodology of systematic geostructural analysis to underground CO2 storage, based on the calculation of the strain field from kinematics indicators on the fault planes (ey and ex for the maximum and minimum horizontal shortening, respectively). This methodology is based on a statistical analysis of individual strain tensor solutions obtained from fresh outcrops from the Triassic to the Miocene. Consequently, we have collected 447 fault data in 32 field stations located within a 20 km radius. The understanding of the fault sets' role for underground fluid circulation can also be established, helping further analysis of CO2 leakage and seepage. We have applied this methodology to Hontomín onshore CO2 storage facilities (central Spain). The geology of the area and the number of high-quality outcrops made this site a good candidate for studying the strain field from kinematics fault analysis. The results indicate a strike-slip tectonic regime with maximum horizontal shortening with a 160 and 50∘ E trend for the local regime, which activates NE–SW strike-slip faults. A regional extensional tectonic field was also recognized with a N–S trend, which activates N–S extensional faults, and NNE–SSW and NNW–SSE strike-slip faults, measured in the Cretaceous limestone on top of the Hontomín facilities. Monitoring these faults within the reservoir is suggested in addition to the possibility of obtaining a focal mechanism solutions for micro-earthquakes (M

The long-term managing from the geological hazard point of view of the Hontomín onshore pilot-plant for CO2 storage, located in Spain and recognized as the first and only key-test facility in Europe, is one of the main objectives stated in the ENOS European project. This project is led and funded by the European Network of Excellence on the Geological Storage of CO2 (CO2GeoNet).The complex geological emplacement of the Hontomín Carbon capture and storage plant is considered rather relevant to analyse the impact of fracturing and both local and regional strain field on the reservoir parameters. The reservoir of Hontomín pilot-plant is formed by highly fractured Middle Jurassic dolomites with associated secondary porosity. This parameter is one of the main concerns when managing CO2 storage and monitoring.In order to characterize the fracture pattern and its implications on a proper CO2 monitoring, we characterized the surface structural elements through the study area and their relationship with fractures affecting the reservoir porosity. The methodology followed in this work is mainly based on detailed geological mapping (field work complimented with orthophoto analysis), adding missing information from previous works. This analysis does not increase the cost for long-term monitoring, given that they are low-cost and the results are acquired in a few months.The main structural trend in the study area, concerning faults with a wide range of displacement and metric to decametric folds, follows a regional E-W orientation. On the other hand, fractures show two main sets of trends, from NW-SE to NE-SW.This fracturing pattern, considered as a conjugate fracture system, corresponds to the tectonic stress recorded in both Mesozoic and Cenozoic sedimentary successions where the Hontomín pilot-plant is placed. Riddle faults formed from a nearby regional right-lateral strike slip fault (Ubierna Fault) are the responsible structures for the fracture system affecting the area and the reservoir. Moreover, this fracturing pattern is in agreement with local to regional active tectonic field from Cenozoic times to present-day, when the Ubierna Fault recorded its maximum right-lateral displacement (15 km).Secondary porosity within the reservoir can be produced from this fracture pattern, highly increasing the permeable migration paths for CO2 migration after the injection. Therefore, we state that a combination between fracture analysis and structural and tectonic study, should be considered as mandatory in the monitoring phases of the CO2 plume, during and after injection operations.

One of the concerns of underground CO2 onshore storage is the triggering of Induced Seismicity and fault reactivation. Hence, a comprehensive analysis of the tectonic parameters involved in the storage rock formation is mandatory for safety management operations. Unquestionably, active faults and seal faults depicting the storage bulk are relevant parameters to be considered. However, there is a lack of analysis of the active tectonic strain field affecting these faults during the CO2 storage monitoring. The advantage of reconstructing the tectonic field is the possibility to determine the strain trajectories and describing the fault patterns affecting the reservoir rock. In this work, we adapt a methodology of systematic geostructural analysis to the underground CO2 storage, based on the calculation of the strain field and defined by the strain field from kinematics indicators on the fault planes (ey and ex for the maximum and minimum horizontal shortening respectively). This methodology is based on statistical analysis of individual strain tensor solutions obtained from fresh outcrops. Consequently, we have collected 447 fault data in 32 field stations located within a 20 km radius. The understanding of the fault sets role for underground fluid circulation can also be established, helping for further analysis about CO2 leakage and seepage. We have applied this methodology to Hontomín onshore CO2 storage facilities (Central Spain). The geology of the area and the number of high-quality outcrops, made this site as a good candidate for studying the strain field from kinematics fault analysis. The results indicate a strike-slip tectonic regime with the maximum horizontal shortening with N160° E and N50º E trend for local regime, which activates NE–SW strike-slip faults and NE–SW compressional faults. A regional tectonic field was also recognized with N–S trend, which activates E–W compressional faults. Monitoring of E–W faults within the reservoir is suggested in addition with the possibility of obtaining focal mechanism solutions for micro earthquakes (M

Contractional deformation in the transition between the Iberian and Catalan Coastal Ranges (Linking Zone) generated both thin-skinned structures detached in low-strength Triassic units and basement-involved structures. To evaluate their extent and relative contribution to the overall structure, we carried out a study combining structural geology and gravimetry. New gravity data (938 stations) and density determinations (827 samples) were acquired and combined with previous existing databases to obtain Bouguer anomaly and residual Bouguer anomaly maps of the study area. Seven serial and balanced cross sections were built, their depth geometries being constrained through the 2.5-D gravity modeling and the 3-D gravity inversion that we accomplished. The residual Bouguer anomaly map shows a good correlation between basement antiforms and gravity highs whereas negative anomalies mostly correspond to (i) Meso-Cenozoic synclines and (ii) Neogene-Quaternary basins. Cross sections depict a southern, thick-skinned domain where extensional, basement faults inherited from Late Jurassic-Early Cretaceous times were inverted during the Cenozoic. To the north, we interpret the existence of both Triassic-detached and basement-involved deformation domains. The two deformation styles are vertically overlapped in the southernmost part of the Catalan Coastal Ranges but relay both across and along strike in the Eastern Iberian Range. These basement and cover relationships and their along-strike variations are analyzed in terms of the interplay between structural inheritance, its obliquity to the shortening direction, and the continuity and effectiveness of Triassic décollements in the study area., This study has been supported by the Instituto para la Reestructuracion de la Mineria del Carbon y el Desarrollo Alternativo de las Comarcas Mineras Ministry of Energy and Industry, Spain. Additional support has also come from the DR3AM and SALTCRES Projects (CGL2014-54118) from the Science National Plan of Spain (MINECO). The authors also acknowledge Midland Valley Exploration for providing Move software academic licenses. The contribution of Jose Maria Llorente, Agustin Gonzalez, and Israel Perez was essential for the acquisition of the geophysical data and the density measurements. The financial support of the Aragonian Goberment is also acknowledged (Applied Geology Group-GeoAp, E01_17R). The data used in this work can be found in the manuscript itself or in previous works listed in the references. Elevation reference data from the Instituto Geografico Nacional (http://www.ign.es/ign/main/index.do) were used in the gravity processing as well as digital terrain models from the Spanish Army Geographical Survey (http://www.ejercito.mde.es/unidades/Madrid/ceget/).Geological maps are available at the IGME website (http://info.igme.es/cartografiadigital/), whereas well data from the Water Authority (CHE) are accessible at the IBER website (http://iber.chebro.es/sitebro/sitebro.aspx?hydrogeoebro).

La interacción entre una cueva hipogénica y la actividad de una falla cuaternaria es la principal responsable de la génesis de la cueva más profunda de la Región de Murcia y una de las mayores cavidades hipogénicas del sur de la península. La Sima de Benís presenta una amplia y única variedad de espeleotemas y de estructuras de disolución que se encuentran afectadas por deformaciones sísmicas producidas tanto por paleoterremotos durante el Pleistoceno Superior, como por terremotos instrumentales (Mw 4,8; VI EMS-98, 1999; Mula). Además, dentro de las zonas más profundas de la cueva aparecen restos fósiles “in situ” de macromamíferos (Lynx pardinus spelaeus), los cuales hemos relacionado con la actividad sísmica en el interior de la caverna. En cuanto a su topografía, esta cavidad presenta dos sectores bien diferenciados: (1) un primer sector de 150-160 m de desarrollo vertical con pozos de origen hipogénico con desarrollo de golpes de gubia y conductos de disolución ascendentes (con “outlets” y “megascallops”) y (2) un segundo sector entre los 150 - 160 m y los 320 m de profundidad, el cual se desarrolla sobre un plano de falla normal de dirección N-S (Falla de Benís). Este segundo sector de la sima es el que presenta evidencias paleosísmicas cuaternarias, dividiéndose a su vez en dos zonas en relación a la dinámica kárstica dominante: (2.a) una zona vadosa dominada por estructuras hipogénicas (donde aparecen folias y corales), junto con marcas cinemáticas de movimiento de la falla (estrías con recristalizaciones y concreciones carbonatadas) y (2.b) una zona freática profunda controlada por la precipitación de nubes de calcita bajo lámina de agua y de tamaño métrico que se desarrolla hasta los - 320 m de profundidad. En cuanto a la parte hipogénica superior de la sima, se desarrolla a favor de una fractura con relleno de calcita y de orientación E-W sobre carbonatos del Cretácico superior y el Paleoceno, con un espesor centimétrico y evidencias de relleno posterior y circulación de fluidos. La potencial actividad paleosísmica ha podido ser datada en 65 ± 17,6 ka (OIS 4) mediante el análisis de racemización de aminoácidos de los colmillos de un lince de las cavernas, el cual pudo ser afectado por un terremoto. Por último, se ha estimado el tamaño del último sismo relacionado con la actividad de la falla a partir de relaciones empíricas, con un valor de Mw oscilando entre 5,5 y 6. Para ello se ha estimado la longitud en superficie de la traza de falla que controla la cueva en profundidad y se ha comparado con el último salto cosísmico observable en el interior de la sima. Estimaciones del salto de falla acumulado y la datación del último paleoterremoto, sugieren que parte de la evolución hipogénica con paleoterremotos de esta cavidad de forma conjunta se produjo al menos, desde hace 250 ka (OIS 7).

The Caspe geological structure was formed by the convergence of the Iberian Range and the Catalonian Coastal Range, during the Tertiary compression. Traditionally, the Caspe structure has been interpreted from seismic profiles without considering surface structural data. The aim of this study is to build a 3D geological model taking into account the structural data from the geological map, stress fields and lineaments, and evaluate its possibility as potential CO2 storage site. Four surfaces have been modelled: Buntsandstein Top, Muschelkalk-I Top, Muschelkalk-II Top and Cenozoic Bottom. Considering the geometry and depth for storage the target reservoir was considered to be the Buntsandstein facies. The available seismic data indicate that the Buntsandstein facies top is at approximately 500 m depth and hosts a deep saline aquifer. The target reservoir series include the conglomerate and sandstone of the Hoz del Gallo and Cañizar Fms (Buntsandstein Facies) with an average thickness of 500 m and 21% porosity. The seal comprises the shales and silts of the Röt Fm with an average thickness of 100-150 m. The structure volume was calculated based on the -500 mbsl for the Buntsandstein top deepest closed contour lines. The estimated volume is 5,800 Mm3 with most of CO2 in gaseous state., Financial support for this study was received from the Spanish administration through the Instituto para la Reestructuración de la Minería del Carbón y el Desarrollo Alternativo de las Comarcas Mineras (IRMC).

León, Ricardo ... et al.-- Special issue Advancements in Understanding Deep-Sea Clastic Sedimentation Processes.-- 20 pages, 14 figures, 1 table, This paper presents a combined onshore-offshore morpho-structural characterization of the El Golfo giant landslide, island of El Hierro (Canary Archipelago, Spain). Offshore data from multibeam echosounders, chirp sub-bottom profiles and multichannel seismic reflection data and onshore data coming from water wells and galleries have been analyzed. The geomorphology and the internal architecture of this giant flank collapse are defined in order to determine its multi-event nature. The subaerial headscarp shows a non-continuous arcuate profile formed by two nested semi-circular amphitheaters that extend offshore along a smooth chute, suggesting the occurrence of at least two large retrogressive events. Channels/gullies and escarpments developed along the submarine sector of the scar also indicate smaller-scale events and predominance of sediment bypass. In the lower slope, two subunits of submarine mass transport deposits (MTDs), debris avalanche, are identified on multichannel seismic reflection profiles with a total estimated volume of 318 km3: ~ 84 km3 and ~ 234 km3, for the younger and older MTDs respectively. Data from wells and galleries show abrasion platforms with beach deposits at sea-level (0 masl) formed after the landslide scar and buried by the post-collapse El Golfo lavas infill, suggesting an age at least older than 23.5–82.5 Ka for the landslide, This work has been supported by the Spanish research project SUBVENT (CGL2012-39524-C02-02) and Project for the Extension of the Continental Shelf West to Canary Islands (CTM2010-09496-E). This research has been also developed within the framework of the IGCP-640 S4SLIDE project (Significance of Modern and Ancient Submarine Slope LandSLIDEs)

Sánchez-García, T. et. al., The Cala project area is a region ca. 400 km 2 in size that comprises several mines and prospects hosted by Palaeozoic rocks. The Cala area is located in the southern segment of the Iberian Massif that forms the pre-Mesozoic basement in most of the Iberian Peninsula and constitutes the westernmost extent of the European Variscan orogeny. More precisely, it is situated in the south-western limb of the Monesterio Antiform, within the Ossa - Morena Zone (OMZ), which exposes a complex geological evolution. The current structure of the OMZ is mainly due to the Variscan orogeny. This study is focused on Variscan plutons that were emplaced into Late Proterozoic and Paleozoic sediments. Igneous and metamorphic activity of the Variscan Orogeny led to the formation of various types of mineralization. Two of these are studied in this paper: the iron oxide replacement and skarn in the Cala mine and the Ni-(Cu-PGE) deposit in the Aguablanca mafic to ultramafic intrusion. The aim of this work is to build three 3D geological models: one at regional scale (Cala regional model) and two at local scale (Cala mine and Aguablanca deposit). To achieve this we have improved the previous geological mapping and carried out two regional gravity surveys and one detailed survey in the neighborhood of Cala mine. Moreover, in order to study the Aguablanca deposit the geological information supplied by Lundin Mining was very useful. The use of geophysical data provide a tool to check the final models. Fully honoring the geological data and starting cross-sections, best processing practices, model properties based on petrophysical data,and the use of a profile mesh providing a great number of intersections where profile consistencies are proven in a 3D environment was the working scheme. The final 3D geological models give a new insight into the Cala and Aguablanca Variscan plutons concerning depth geometry, volume of mineralization and geological environment, not previously know. The regional model provides the geological context of the complex geological evolution that took place in the southern segment of the Iberian Massif. Furthermore, a predictive model has been constructed, including three areas of high potential for mineralization, based on geophysical studies. In addition occurrences of magnetite deposits related to replacement or skarn formation and possible uranium enrichment would be expected based on the predictive models., This study has been partly funded by the ProMine project “Nano-particle products from new mineral resources in Europe ”, within the VIII Framework Programme for research (NMP-2008-4.0-5, contract 228559) and IGME (project Nº 72.5.00.16.00).