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20 pages, 3 figures, A marine hazard is a potentially damaging event, phenomenon or activity in the marine environment that may cause loss of human life, social and economic disruption or environmental degradation. In the last 30 years, natural and human-induced hazards have caused over 1.6 million victims and the economic losses average 300 thousand million dollars per year. Marine hazards are amongst the most devastating ones. Here we present the research challenges we face as a society to achieve a safer ocean whereby human communities and the environment are better protected from the most outstanding biological, climatic and geological threats. We advocate for the implementation of a multi-hazard research strategy with emphasis on trans-disciplinary collaboration, development of improved observational infrastructures and data-sharing platforms, multi-hazard warning and management, and effective transfer of information to stakeholders and authorities to enhance impact mitigation

The eastern Algarve continental shelf in the northern margin of the Gulf of Cadiz has been investigated by analysing a set of high-resolution seismic reflection profiles. We examine the major structural elements affecting the upper sedimentary units. A seismo-stratigraphic interpretation and regional correlation allowed the identification of a major discontinuity that separates two main intervals, pre-Middle Pleistocene (MP) and post-MP. In addition, a number of deformation features such as ENE-WSW to NE-SW thrusts, kilometric-scale N-S to NW-SE folds and NNE-SSW to NNW-SSE sub-vertical normal faults were identified affecting the Pliocene-Quaternary sedimentary record, indicating neotectonic activity. The structures pre-dating MP are in agreement with a dominant transpressive regime along the continental shelf, under the Late Cenozoic NW-SE oblique convergence and related to the reactivation of Mesozoic diapiric structures. The structures post-dating MP induce a lower deformation of the sedimentary cover but were still active during the last glacial maximum, in agreement with the low uplift recognized in the Portuguese mainland., [ES] La plataforma continental del Algarve en el margen septentrio-nal del Golfo de Cádiz ha sido investigada mediante el análisis de una red de perfiles sísmicos de alta resolución. Se presentan las prin-cipales estructuras que afectan a la cobertera sedimentaria super-ficial. Una interpretación sismoestratigráfica y correlaciones a nivel regional han permitido diferenciar dos intervalos separados por una discontinuidad principal, anterior y posterior al Pleistoceno Medio (PM). Los depósitos del Plioceno y Cuaternario están deformados por estructuras de deformación tales como cabalgamientos ENE-OSO a NE-SO, pliegues N-S a NO-SE de escala kilométrica y fallas subverticales NNE-SSO a NNO-SSE, que indican actividad neotec-tónica. Las estructuras anteriores al PM se generan en relación con el régimen transpresivo (NO-SE) dominante a fInales del Cenozoico en esta región y la reactivación de las estructuras diapíricas mesozoicas observadas en el margen. En cambio, las estructuras posteriores al PM producen una ligera deformación de la cobertera sedimentaria y actividad durante el último máximo glaciar, lo que concuerda con un moderado levantamiento tectónico observado en la zona conti-nental del margen portugués., The research was supported through projects CGL2011-30302 and CTM2017- 88237-P and Group RNM-373 of Junta de Andalucía. We are very grateful to Javier Hernández Molina for his critical reading of the manuscript. We thank Guillermo Booth and Ferrán Estrada for their detailed reviews and constructive comments of the original version of the manuscript.

X Congreso Geológico de España, 5-7 de julio 2021, Vitoria-Gasteiz.-- 4 pages, 4 figures, [EN] The Gulf of Cadiz upper slope in the area close to the Strait of Gibraltar is covered by a plastered drift deposited by the activity of the Mediterranean Outflow Water (MOW) and the North Atlantic Central Water (NACW). A number of small gullies are incised across the plastered drift, due to the interaction between gravitational and contouritic processes. The study of parametric sounder profiles and sedimentological analyses of nine sediment cores obtained from the axes of two gullies and from the undisturbed upper slope, giving a Holocene age frame, has allowed analyzing the recent sedimentary processes and their spatial and temporal variability. The upper slope shows a general increase in grain size towards the NW, suggesting bottom current intensification and/or the occurrence of gravity flows from the continental shelf and shelf-edge. The two studied upper slope gullies display significant differences in their recent activity and dominant processes. The one located to the SE seems to have been inactive since about 5.9 ka, and it has been draped by contouritic deposits. In contrast, the gully located to the NW has been a sediment transport conduit for the entire time span recorded in the sediment cores, [ES] El talud superior del margen Ibérico del Golfo de Cádiz en las proximidades del Estrecho de Gibraltar está ocupado por un depósito contornítico adosado resultado de la circulación del Agua Mediterránea de Salida (Mediterranean Outflow Water, MOW) y de la Masa de Agua Central Noratlántica (North Atlantic Central Water, NACW). En él se encajan pequeños valles submarinos (gullies) debido a la interacción entre los procesos gravitacionales y contorníticos. Mediante el estudio de perfiles de sonda paramétrica y el análisis sedimentológico de nueve testigos obtenidos en el área del talud superior no afectada por gullies y en los ejes de dos gullies, cuya datación corresponde al Holoceno, este estudio analiza los procesos sedimentarios recientes y su variabilidad espacial y temporal. El talud superior muestra un incremento general del tamaño de grano hacia el NO, indicativo de intensificación de las corrientes y/o el aporte sedimentario de origen gravitacional desde la plataforma continental y borde de plataforma. Los dos gullies estudiados muestran una gran variabilidad en los procesos predominantes. El gully más meridional, dominado actualmente por la sedimentación contornítica, parece haber sido inactivo desde unos 5.9 ka. En cambio, el gully localizado más al NW ha canalizado flujos gravitacionales durante todo el intervalo registrado por los testigos, We acknowledge funding from the Talus (CGL2015-74216-JIN), Inpulse (CTM2016-75129-C3-1-R), Contouriber (CTM2008-06399-C04/MAR), Mower (CTM2012-39599-C03), Fauces (CTM2015-65461-C2-1-R) and Score (CGL2016-80445-R) projects. This work has benefited from the collaborations within the Drifters” Research Group (RHUL)

58th British Sedimentological Research Group AGM, 13-17 December 2019, London.-- 1 page, The Cadiz upper slope is located at the Atlantic exit of the Strait of Gibraltar (latitude 36º10’-36º40’N). It runs from the continental shelf-edge at ~120 mwd to the connection with the middle slope at 400-500 mwd. It is covered by a plastered contouritic drift created by the Mediterranean Outflow Water (MOW) and incised by upper slope gullies. This work investigates the interaction between gravitational and contouritic processes under the influence of a highly dynamic tectonic regime controlled by diapiric activity rooted in the Gulf of Cadiz Allochtonous Unit. Tectonic activity and sedimentary processes are inferred from the stratigraphic analysis of airgun seismic profiles that cover the sedimentary record from the Mid Pleistocene. Two seismic units have been identified and placed in a regional chronostratigraphic framework. The lower unit SU-II (Mid Pleistocene to Late Quaternary) is deformed by the activity of NE-SW-oriented outcropping and buried diapirs. It shows layered and wavy reflections in the southern upper slope, where some gullies occur related to diapir-rooted faults; parallel layered reflections prevail in the northern upper slope where only a few gullies occur in inter-diapir basins. This unit is interpreted as patchy plastered drifts that infilled the space created by the diapiric uplift as the main Mediterranean Outflow Water (MOW) flowed through a channel located about 5 km to the east of a major present-day contourite channel (i.e., the Cadiz contourite channel). The upper seismic unit SU-I (Late Quaternary-Present) records the inactivation of most of the NE-SW-oriented buried diapirs, and the activity of the outcropping diapiric ridges and buried NW-SE-oriented diapirs. This unit is composed of four sub-units (SU-ID to SU-IA). The lower two sub-units led to the progradation of the southern upper slope and the migration of the main channel to its present-day position. Along-slope sedimentation took over as the main morpho-sedimentary process due to the strengthening of the MOW upper core, as suggested by the orientation of depocenters and the occurrence of wavy deposits in the northern upper slope. Gullies incision and slope instability in the southern area resulted from renewed diapiric activity. Sub-unit SU-IB records a quiet tectonic stage. Layered high-acoustic amplitude reflections on the upper slope are interpreted as a plastered drift deposited under a tabular flow of the MOW. The last stage (sub-unit SU-IA) is characterized by a reactivation of the NW-SE-oriented buried diapiric highs and the outcropping diapiric ridges, and the onset of sedimentary instability that eroded the previous sub-unit. Mounded drifts infilled the eroded surfaces and a new plastered drift covered the entire upper slope. The incision of gullies was particularly important in the southern area, although their asymmetric pattern and NW migration suggests important MOW influence. The northern area is characterized by downslope prograding chaotic-transparent deposits with sediment waves, suggesting high sedimentation rates and flow instability related to diapir uplift. This work revealsthat the paleoceanographic and paleoclimatic interpretations of deep-water environments require a careful analysis of the tectonic control influencing the complex interplay between downslope and along-slope sedimentation

Workshop. Alboran Domain and Gibraltar Arc: Geological Research and Natural Hazards - El dominio de Alborán y el Arco de Gibraltar: Investigación geológica y riesgos naturales - Le Domaine Alboran et l'Arch de Gibraltar: Recherche géologique et risques naturels, 16-18 octubre 2019, Granada..-- 2 pages, El talud superior de Cádiz se sitúa en las cercanías del Estrecho de Gibraltar (latitud 36º10’N-36º40’N), desde el borde de la plataforma, en torno a 120 m de profundidad, hasta la conexión con el talud medio a 400-500 m. Mediante el análisis de perfiles de sísmica de reflexión de diferentes resoluciones y de mapas batimétricos del talud, este trabajo explora la relación entre procesos estructurales profundos, principalmente diapiros y altos estructurales relacionados con la actividad de la Unidad Alóctona del Golfo de Cádiz, con los procesos sedimentarios deposicionales y erosivos derivados del flujo de las masas de agua y los procesos gravitacionales en el talud superior. El registro sedimentario reciente desde el Pleistoceno medio hasta la actualidad en el talud de Cádiz se divide en dos unidades sísmicas, correlacionadas con el marco estratigráfico regional (Hernández-Molina et al., 2016). Ambas unidades definen la construcción de un depósito contornítico adosado al talud superior (Hernández-Molina et al., 2013) y su continuación como depósito laminar en el talud medio. Sin embargo, muestran diferencias significativas en cuanto a su distribución y sus características sísmicas. También se identifican variaciones importantes en su configuración interna, entre la parte SE de la zona de estudio, donde el talud superior conecta con el canal contornítico de Cádiz, y la parte NW donde conecta con depósitos laminares del talud medio. La unidad inferior (Pleistoceno medio-Cuaternario inferior) está deformada por la actividad de numerosos diapiros, en particular en la zona SE, según revela la inclinación y acuñamiento de los reflectores hacia los edificios diapíricos. Sus principales depocentros se distribuyen en las zonas deprimidas entre altos diapíricos, y su configuración interna incluye reflectores estratificados paralelos en la zona NW y ondulados en la zona SE. Por el contrario, la unidad superior (Cuaternario inferior- presente) se distribuye de forma más homogénea en el talud superior actual, mostrando deformación por efecto de diapiros sólo en la parte NW del área de estudio, que afecta hasta el registro más superficial. En esta unidad se desarrollan los principales rasgos morfo-estratigráficos que definen la configuración actual del margen: progradación del talud, canales contorníticos relacionados con las dorsales diapíricas, y valles submarinos de origen gravitacional que muestran mayores profundidades de incisión en la parte SE del área de estudio. La configuración interna de la unidad superior muestra reflectores ondulados en el talud superior de toda la zona de estudio. La interpretación preliminar de estos datos indica que la construcción del talud de Cádiz desde el Pleistoceno medio ha estado fundamentalmente controlada por una compleja interacción entre los procesos tectónicos recientes relacionados con la actividad de los diapiros fósiles o aflorantes y la dinámica de las masas de agua y sus interfases. La variabilidad del registro sísmico y morfológico entre las zonas SE y NW del área de estudio sugiere una progresiva migración de la actividad diapírica hacia el NW, donde controla los procesos sedimentarios recientes. En cambio, en la zona SE la sedimentación reciente está más dominada por los procesos oceanográficos, y por su interacción con procesos gravitacionales, Esta investigación ha sido financiada por los proyectos Talus (CGL2015-74216-JIN), Inpulse (CTM2016-75129-C3-1-R), Graco (Eurofleets2), Mower (CTM2012-39599-C03-02) y Contouriber (CTM2008-06399-04-04)

II Congreso de Jóvenes Investigadores del Mar, Universidad de Málaga, del 1 al 4 de octubre de 2019

34th IAS Meeting of Sedimentology in Rome (Italy), 10-13 september, 2019

XIII ISAES 2019 will be held from 22-26 July 2019, in Incheon, Republic of Korea

ISAES 2019: XIII International Symposium on Antarctic Earth Sciences, Songdo Convensia, Incheon, Republic of Korea, 22-26 july (2019)

International Conference “Marine Geology and Deep Sea Exploration” Guangzhou, PR China, November 25-28, 2019

EGU 2019, Vienna ( Austria), 7–12 April 2019

Workshop Alboran domain and Gibraltar Arc: geological research and natural hazards, Granada (España), 16-18 octubre (2019)

20th International Sedimentological Congress (ISC), 13-17 August 2018, Quebec City, Canada.-- 1 page, Gullies are ubiquitous erosive features in continental margins that are mainly related to downslope, low-density gravitational flows (turbidites), although mass transport and fluids migration may be involved in their genesis and evolution. A series of downslope-trending gullies have been identified on the relatively smooth, slightly concave-upward upper slope of the Gulf of Cadiz, close to the Strait of Gibraltar. They extend from 205-250 m (beyond the continental shelf) to 510-580 m water depth, at the Cadiz Channel northern flank along the middle slope. The occurrence of gullies in this region, characterized by active contouritic processes affected by diapiric ridges, suggests an interaction between bottom current processes and the downslope-trending gullies. This interaction is investigated in this work, based on the analysis of very high-resolution data including swath bathymetry, echo-sounder parametric profiles and sediment cores up to 310 cm long. The gullies are generally asymmetric, with steeper and higher NE walls. Overall, they are arranged in a dendritic, convergent pattern laterally spaced 0.4-2 km. Parametric profiles show that both the gullies and inter-gully areas are covered by a thin, low reflectivity sheet-like layer, up to 10 milliseconds (two-way travel time) thick, that become thicker in the gullies SE flank. Three sediment cores collected along the axis of one single gully exhibit vertically homogeneous muddy sand and sandy mud, but with clear occasional smaller coarsening-upward sequences. In contrast, two sediment cores collected in the adjacent undisturbed upper slope contain finer sediment (mud to sandy mud) that exhibit general and smaller-scale coarsening-upward trends. These results suggest that the upper slope is affected by an increasing effect of the Mediterranean flow and the gullies are inactive features at present. This may imply that the upper slope of the Gulf of Cadiz records changes in the oceanographic control and turbiditic activity probably related to changes in the vertical distribution of water masses with glacio-eustatic cyclicity, This work is supported by the Spanish Research Plan (TALUS Project CGL2015-74216-JIN, SCORE Project CGL2016-80445-R and INPULSE Project CTM2016-75129-C3-3-R). The dataset was obtained during the GRACO Cruise, funded by the Eurofleets2 Program (EC, Grant agreement 312762). The study is partially conducted in the framework of “TheDrifters Research Group” at the Royal Holloway University of London (UK)

Simposio sobre el Margen Ibérico Atlántico (9º. 2018. Coimbra, Portugal), The evolution of a mud entrapment confined to the paleo-Guadiana incised valley was investigated and interpreted in terms of environmental changes. High-resolution seismic data and a gravity core were analyzed. Two distinct intervals were identified. The lower part of the sediment core recorded a transient increase of the gravel and sand fractions and low sedimentation rate, interpreted either as low sediment inputs to the shelf, or the prevalence of erosional processes in this area promoted by high-energy events. The upper part of the core, depicting the recent sedimentation, is dominated by fine-grained sediments and showed increasing abundances of benthic foraminiferal species influenced by river discharges. In general, sedimentological and benthic foraminiferal variations indicated environmental changes that were driven by variable sediment supplies to the shelf promoted by high-energy events, related with the regional record of floods and storms., Centro de Investigação Marinha e Ambiental, Universidade do Algarve, Portugal, Instituto Andaluz de Ciencias de la Tierra, España, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Alemania, Instituto Geológico y Minero de España, España, Department of Coastal and Marine Systems Sciences, Coastal Carolina University, Estados Unidos, Department of Geosciences, University of Bremen, Alemania

3rd Deep-Water Circulation Conference (3DWC), Multidisciplinary Perspective, 14-16 September 2017, Wuhan - Wu Han

Reunião do Quaternário Ibérico (9º. 2017. Algarve), Recent environmental changes associated with high-energy events and human impacts were investigated in a mud entrapment confined in the paleo-Guadiana incised valley. Those changes were recorded in a gravity core during the last 2500 years. An erosional event seems to have occurred at ca. 500 cal yr BP but it is not clear how much sediment was removed. This event was followed by an increase in river discharges until ca. 465 cal yr BP while the benthic foraminiferal faunas were dominated by species associated with shallow-water sandy sediments. Upward, sedimentological and benthic foraminiferal variations indicated environmental changes, promoted by variable sediment supplies to the shelf., Centro de Investigação Marinha e Ambiental, Universidade do Algarve, Portugal, Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, España, Instituto Andaluz de Ciencias de la Tierra, Universidad de Granada, España, GEOMAR Helmholtz Centre for Ocean Research Kiel, Alemania, Instituto Geológico y Minero de España, España, School of Coastal and Marine Systems Sciences, Coastal Carolina University, Estados Unidos, Department of Geosciences, University of Bremen, Alemania

Prodeltaic depositional systems can be used as high-resolution archives, since they sensitively record environmental changes occurred during their formation. On the inner shelf off the Guadiana River, northern Gulf of Cádiz, the recent deposition is mainly driven by river discharge, which reflects both climate variability and human-induced processes in the river basin. The purpose of this study is to unravel rainfall variability and human impacts on the river basin, recorded on the Guadiana prodeltaic wedge, over the past decades. A multiproxy study including the analyses of benthic foraminiferal assemblages, grain size and geochemical element distribution (X-ray fluorescence core scanning), constrained in a chronological framework (based on radiocarbon dating and Pb-210), was performed on core GeoB19522. This core was collected in March 2015, during the RV Poseidon cruise POS482 CADISED, on the Guadiana prodeltaic wedge at 13.5 m water depth, which is an area with high sedimentation accumulation rates and consequent detailed temporal resolution. The upper part of the sediment core (from 1.6 m depth to the top) is dominated by the silt-clay fraction (77-99%), occasionally with higher percentages of sand (0.2-23 %). The element ratios and the benthic foraminiferal fauna show significant temporal variations. Some of the identified species can be regarded as successful colonizers (Textularia earlandi, Reophax arctica) and others as opportunistic species linked with river discharges and the limits of productivity (Bolivina ordinaria, Hopkinsina atlantica). These variations point to changes in the environment, promoted by periods of increase or decrease sediment supply to the shelf. info:eu-repo/semantics/publishedVersion

Lobo, F.J. et. al.-- 31 pages, 10 figures [EN] We present a synthetic view of continental-shelf evolutionary patterns around the Iberian Peninsula, focusing on proposed sequence stratigraphy interpretations and attempting a comparison between Atlantic- and Mediterranean-type shelf-margin constructions. Most of the studied shelves show a dominance of regressive to lowstand deposition through successive progradations, particularly evident in the Pliocene-Quaternary, documenting the influence of glacio-eustasy. Transgressive to highstand development predating the Last Glacial Maximum seems to be favoured off major rivers, but the highest variability is seen during postglacial evolution. Transgressive deposits tend to show a higher spatial variability, ranging from prograded parasequences to extensive sand sheets. Holocene highstand deposits usually show a more homogeneous character, with development of proximal wedge-shaped deposits and a distal sheet-like deposition. Atlantic continental shelves off Iberia display three different types of shelf growth: depositional shelves, shelves with restricted progradation and erosional shelves. They result from the interplay between depositional and hydrodynamic regimes, with the occurrence of a latitudinal gradation from erosional shelvesn the Cantabrian continental shelf to depositional shelves in the northern Gulf of Cadiz shelf. Some shelf sectors do not correspond to this general pattern, as shelf sedimentation is mainly controlled by morpho-structural features (e.g., ria environments and shelves crossed by major tectonic accidents). The Mediterranean continental shelves of Iberia show two basic types, high- versus low-supply shelves, and their growth patterns are mainly a response to the amount of fluvial supply. The low-supply style is clearly the most frequent type, and it may show further complexity according to the occurrence of submarine canyons and/or morpho-structural control. © 2015, Instituto Geologico y Minero de Espana. All rights reserved [ES] Presentamos una visión sintética de los patrones sedimentarios evolutivos de las plataformas continentales de la Península Ibérica, con un énfasis particular en las interpretaciones de estratigrafía secuencial propuestas y con el objetivo de realizar una comparación entre los estilos de construcción de plataformas continentales en el Atlántico y el Mediterráneo. La mayor parte de las plataformas estudiadas muestran un claro predominio de los depósitos progradantes desarrollados durante intervalos de descenso relativo y de bajo nivel del mar, lo cual es particularmente evidente en el registro sedimentario Plioceno-Cuaternario, reflejando el control primario de los cambios glacioeustáticos. Los depósitos transgresivos y de alto nivel del mar previos al Último Máximo Glacial parecen estar mejor representados en plataformas continentales influenciadas por los grandes cursos fluviales. Los depósitos transgresivos postglaciales muestran una gran variabilidad espacial, cambiando lateralmente desde parasecuencias progradantes hasta extensas láminas arenosas. Por el contrario, los depósitos de alto nivel del mar Holocenos muestran un carácter más homogéneo, con desarrollo de cuñas sedimentarias proximales y depocentros fangosos distales. Los diferentes estilos de crecimiento de las plataformas continentales atlánticas de Iberia resultan básicamente de la interacción entre los regímenes deposicionales e hidrodinámicos, observándose una gradación latitudinal de plataformas desde la plataforma erosiva del Mar Cantábrico a la plataforma deposicional del Golfo de Cádiz. Localmente, se identifican algunos sectores de la plataforma que no responden a este patrón general, sino que su crecimiento está controlado por rasgos morfo estructurales (por ejemplo, los ambientes de rías y las plataformas atravesadas por accidentes tectónicos mayores). Los patrones de crecimiento de las plataformas mediterráneas de Iberia están estrechamente relacionados con el aporte fluvial, diferenciándose dos estilos básicos: plataformas con alto aporte y plataformas con bajo aporte sedimentario. El estilo de bajo aporte sedimentario es el tipo más frecuente, el cual puede mostrar una mayor complejidad en función de la existencia de cañones submarinos y/o de rasgos morfoestructurales This paper was completed thanks to the support of the following research projects: CGL2011-30302-C02-02 and CGL2012-33989 funded by the Spanish R+D Program, MOSAICO (P06-RNM-01594) and TESELA (P11-RNM7069) funded by the Andalusian R+D Program. Ruth Durán acknowledges a CSIC JAE-Doc contract co-funded by the FSE. Marta Ribó is supported by a FPI grant (Ref. BES-2010-029949) from the Spanish Ministry of Economy and Competitiveness. Isabel Mendes thanks the Portuguese Foundation for Science and Technology (FCT) for grant SFRH/BPD/72869/2010. This study is a contribution to INQUA IFG: Rapid environmental changes and human impact on continental shelves

Lobo, F.J. et. al.-- 31 pages, 10 figures, [EN] We present a synthetic view of continental-shelf evolutionary patterns around the Iberian Peninsula, focusing on proposed sequence stratigraphy interpretations and attempting a comparison between Atlantic- and Mediterranean-type shelf-margin constructions. Most of the studied shelves show a dominance of regressive to lowstand deposition through successive progradations, particularly evident in the Pliocene-Quaternary, documenting the influence of glacio-eustasy. Transgressive to highstand development predating the Last Glacial Maximum seems to be favoured off major rivers, but the highest variability is seen during postglacial evolution. Transgressive deposits tend to show a higher spatial variability, ranging from prograded parasequences to extensive sand sheets. Holocene highstand deposits usually show a more homogeneous character, with development of proximal wedge-shaped deposits and a distal sheet-like deposition. Atlantic continental shelves off Iberia display three different types of shelf growth: depositional shelves, shelves with restricted progradation and erosional shelves. They result from the interplay between depositional and hydrodynamic regimes, with the occurrence of a latitudinal gradation from erosional shelvesn the Cantabrian continental shelf to depositional shelves in the northern Gulf of Cadiz shelf. Some shelf sectors do not correspond to this general pattern, as shelf sedimentation is mainly controlled by morpho-structural features (e.g., ria environments and shelves crossed by major tectonic accidents). The Mediterranean continental shelves of Iberia show two basic types, high- versus low-supply shelves, and their growth patterns are mainly a response to the amount of fluvial supply. The low-supply style is clearly the most frequent type, and it may show further complexity according to the occurrence of submarine canyons and/or morpho-structural control. © 2015, Instituto Geologico y Minero de Espana. All rights reserved, [ES] Presentamos una visión sintética de los patrones sedimentarios evolutivos de las plataformas continentales de la Península Ibérica, con un énfasis particular en las interpretaciones de estratigrafía secuencial propuestas y con el objetivo de realizar una comparación entre los estilos de construcción de plataformas continentales en el Atlántico y el Mediterráneo. La mayor parte de las plataformas estudiadas muestran un claro predominio de los depósitos progradantes desarrollados durante intervalos de descenso relativo y de bajo nivel del mar, lo cual es particularmente evidente en el registro sedimentario Plioceno-Cuaternario, reflejando el control primario de los cambios glacioeustáticos. Los depósitos transgresivos y de alto nivel del mar previos al Último Máximo Glacial parecen estar mejor representados en plataformas continentales influenciadas por los grandes cursos fluviales. Los depósitos transgresivos postglaciales muestran una gran variabilidad espacial, cambiando lateralmente desde parasecuencias progradantes hasta extensas láminas arenosas. Por el contrario, los depósitos de alto nivel del mar Holocenos muestran un carácter más homogéneo, con desarrollo de cuñas sedimentarias proximales y depocentros fangosos distales. Los diferentes estilos de crecimiento de las plataformas continentales atlánticas de Iberia resultan básicamente de la interacción entre los regímenes deposicionales e hidrodinámicos, observándose una gradación latitudinal de plataformas desde la plataforma erosiva del Mar Cantábrico a la plataforma deposicional del Golfo de Cádiz. Localmente, se identifican algunos sectores de la plataforma que no responden a este patrón general, sino que su crecimiento está controlado por rasgos morfo estructurales (por ejemplo, los ambientes de rías y las plataformas atravesadas por accidentes tectónicos mayores). Los patrones de crecimiento de las plataformas mediterráneas de Iberia están estrechamente relacionados con el aporte fluvial, diferenciándose dos estilos básicos: plataformas con alto aporte y plataformas con bajo aporte sedimentario. El estilo de bajo aporte sedimentario es el tipo más frecuente, el cual puede mostrar una mayor complejidad en función de la existencia de cañones submarinos y/o de rasgos morfoestructurales, This paper was completed thanks to the support of the following research projects: CGL2011-30302-C02-02 and CGL2012-33989 funded by the Spanish R+D Program, MOSAICO (P06-RNM-01594) and TESELA (P11-RNM7069) funded by the Andalusian R+D Program. Ruth Durán acknowledges a CSIC JAE-Doc contract co-funded by the FSE. Marta Ribó is supported by a FPI grant (Ref. BES-2010-029949) from the Spanish Ministry of Economy and Competitiveness. Isabel Mendes thanks the Portuguese Foundation for Science and Technology (FCT) for grant SFRH/BPD/72869/2010. This study is a contribution to INQUA IFG: Rapid environmental changes and human impact on continental shelves

Fernández-Salas, L.M. ... et. al.-- 49 pages, 9 figures, [EN] Here we present a synthesis of bedforms and sediment types on the shelves surrounding the Iberian Peninsula and the Balearic Islands, after the integration several pieces of bathymetric, morphological and sedimentological datasets. The Iberian and Balearic shelves are divided into segments according to the large-scale margin configuration, fluvial sediment supply and hydrodynamic regime. Their geological settings and large-scale sedimentation patterns place the investigated shelves into two broad categories: abrupt, steep and narrow sediment-starved shelves, illustrated by the Cantabrian shelf, and gentle, smooth and wide sediment-fed shelves, such as the shelves off some major flivial systems. An in-depth classification was subsequently attempted, based on morpho-sedimentary types. Under this approach, the Iberian and Balearic shelves can be classified as: (1) storm-dominated shelves, with erosional rocky floors, frequent abrasion surfaces and coarse-grained sediments; (2) current-dominated shelves, showing a good equilibriumbetween sediment fluxes and coastal and shallow ocean circulation, with laterally extensive muddy belts; (3) sediment supply-dominated shelves, where extensive subaqueous deltas develop off river mouths; and (4) wave-dominated shelves that occur off coastal stretches with minor and/or multiple fluvial sediment sources and enhanced littoral current. © 2015, Instituto Geologico y Minero de Espana. All rights reserved, [ES] En este estudio se presenta una síntesis de los tipos morfológicos y de los sedimentos superficiales que cubren las plataformas alrededor de la Península Ibérica y las Islas Baleares, integrando datos de distinta naturaleza (datos batimétricos y cartografía de tipos morfológicos y sedimentarios). La plataforma fue subdividida en varios sectores de acuerdo con la configuración general de los márgenes continentales y las condiciones regionales del aporte fluvial y de la hidrodinámica. Las plataformas ibérica y balear se dividen básicamente en dos categorías en función del contexto geológico y los patrones sedimentarios a escala del margen continental: plataformas desnutridas abruptas, inclinadas y estrechas, como la plataforma cantábrica como ejemplo más significativo, y plataformas nutridas suaves, poco inclinadas y anchas, tales como los sectores de plataforma frente a los principales sistemas fluviales. Una clasificación más pormenorizada se realizó teniendo en cuenta la distribución de tipos morfosedimentarios. De esta forma, las plataformas de la península ibérica y de las islas Baleares pueden ser clasificadas en: (1) plataformas erosivas rocosas, controladas por regímenes de tormentas energéticas, caracterizadas por extensas superficies de abrasión y sedimentos groseros; (2) plataformas dominadas por las corrientes, que muestran un equilibrio entre los flujos sedimentarios y la circulación somera, que conduce al desarrollo de cinturones fangosos de elevada continuidad lateral; (3) plataformas dominadas por los aportes, con desarrollo de grandes depósitos deltaicos submarinos frente a ríos grandes y medios; (4) plataformas dominadas por el oleaje, frente a sectores costeros con (múltiples) aportes fluviales menores y condiciones de deriva litoral activa, This paper was completed thanks to the support of the following research projects: CGL2011-30302-C02- 02, COSTEM (CTM2009-07806) and FORMED (CGL2012-33989) funded by the Spanish R+D Program, MOSAICO (P06-RNM-01594) and TESELA (P11-RNM7069) funded by the Andalusian R+D Program. Miquel Canals and Ruth Duran acknowledge Generalitat de Catalunya autonomous government for its support to GRC Geociències Marines through grants 2009 SGR 1305 and 2014 SGR 1068 to Excellence Research Groups. Ruth Durán acknowledges a CSIC JAE-Doc contract co-funded by the FSE. Isabel Mendes thanks the Portuguese Foundation for Science and Technology (FCT) for grant SFRH/BPD/72869/2010. Marta Ribó is supported by a FPI grant (Ref. BES-2010-029949) from the Spanish Ministry of Economy and Competitiveness. The Basque Country continental shelf mapping was supported by the Department of Environment, Land Use, Agriculture and Fisheries, of the Basque Government. This study is a contribution to IGCP project 588 (Preparing for coastal change: a detailed processresponse framework for coastal change at different timescales), to INQUA IFG Rapid environmental changes and human impact on continental shelves and to MeshAtlantic project (Atlantic Area Transnational Cooperation Programme 2007 and 2013 of the European Regional Development Fund) (http://www.meshatlantic.eu )

24 pages, 14 figures, 1 table, The Iberian Mediterranean shelves are divided into three different geographical segments (the Northeastern Shelf, the Southeastern Shelf and the Northern Alboran Sea Shelf), the understanding of which has evolved over the years. The best known sector is the Northeastern Shelf, comprising the narrow, abrupt and prograding Catalonia Shelf and the wider, prograding Ebro Shelf–Gulf of Valencia, where pioneering Spanish marine geology studies have been conducted since the 1970s. The knowledge of the Quaternary stratigraphic architecture of the Northeastern Shelf is very detailed, and provides an outstanding example of regressive–transgressive cycles leading to shelf build-up with various margin configurations. The Southeastern Shelf exhibits a change of margin configuration from intermediate to abrupt in response to declining fluvial influence. The knowledge of this shelf is limited in comparison with the rest of the Iberian Mediterranean shelves. Abundant studies have also been performed on the Northern Alboran Sea Shelf, which, in contrast to the Northeastern Shelf, does not have a major fluvial source but numerous short, mountain rivers draining from the Betic Cordillera. For this shelf, a high-resolution sequence stratigraphy model has been proposed for the most recent Late Quaternary depositional sequence

The Adra submarine delta is located on the northern Alboran Sea shelf in the western Mediterranean Sea. The genesis of this deltaic system is associated with the discharges of the short and mountainous Adra River. The area is under the influence of a Mediterranean climate with sporadic winter torrential flows and increased summer aridity. Major anthropogenic activities in the river system occurred in 1872 AD, with the deviation of the main fluvial course to the east. The channel was silted up in 1910 AD as result of a flood event and relocated further west, at its present position. These artificial changes are reflected in the submarine morpho‐stratigraphy of the delta that is composed of two main lobes. In order to understand the interaction between river discharges and the evolution of the submarine delta at different timescales, two sediment cores were collected from both lobes. A chronological framework was performed and combined with sedimentological and benthic foraminiferal analyses. Radiocarbon dating of plant debris from the base of the cores indicates that the sedimentary record goes back 250 years BP. The correlation of sediment cores with seismic records indicate that both cores penetrated the same seismic unit, deposited between ca. 1070 to ca. 1872 AD, under the direct influence of the ancient river course. The predominant sedimentary facies is sandy silt with intercalated sand layers. The uppermost core sections are pure sand. The number of benthic foraminifera is generally below 100 specimens per gram. The most abundant species in both cores are Ammonia tepida, Bolivina ordinaria, Nonionella stella, Reophax arctica and Textularia earlandi. The increases of sand and the low faunal density, followed by increased abundance of successful colonizers and opportunistic species, is interpreted as result of periods of high precipitation, and sediment supply to the shelf, and the subsequent establishment of an environment with new ecological constrains. info:eu-repo/semantics/publishedVersion

The use of modified live virus (MLV) vaccines is a common procedure to control porcine reproductive and respiratory syndrome virus (PRRSV) infection in the great majority of countries from America, Asia and Europe, including Spain. Current discriminatory techniques allow the detection of different MLV type-II vaccine strains. Herein we report a rapid and accurate technique aimed to discriminate between MLV type-I vaccine strains and Spanish field strains. This technique comprises a reverse transcription (RT) and nested polymerase chain reaction (nPCR) amplification of PRRSV ORF5 followed by a digestion of RT-nPCR products with two specific endonucleases, ItaI and AccI. Combined utilization of ItaI and AccI generates restriction fragments length polymorphisms (RFLP) patterns adequate for the differentiation of 30 Spanish field isolates, of which 12 were isolated between 1991 and 1995 and 18 between 2000 and 2003. These different RFLP patterns can be used to distinguish unequivocally between Spanish field strains of PRRSV and the three MLV type-I vaccines used in Spain: AmervacPRRS®, Pyrsvac-183® and PorcilisPRRS®., Para controlar la infección por el virus del síndrome reproductor y respiratorio porcino (PRRSV), en la gran mayoría de países de América, Asia y Europa, incluyendo España, se usan frecuentemente vacunas basadas en virus vivos modificados (MLV). En la actualidad existen técnicas discriminatorias que permiten detectar cepas vacunales del PRRSV de tipo II. El presente trabajo describe una técnica precisa y rápida para la diferenciación de cepas vacunales de tipo I del PRRSV y cepas de campo españolas. Esta técnica se basa en la transcripción reversa y posterior amplificación de la ORF5 del genoma del PRRSV utilizando la reacción en cadena de la polimerasa anidada, seguida de la digestión de los amplicones generados con dos endonucleasas específicas: ItaI y AccI. La utilización combinada de ambas enzimas genera patrones de polimorfismos en la longitud de fragmentos de restricción (RFLP), adecuados para la distinción de las 30 cepas de campo usadas, de las cuales 12 fueron aisladas entre 1991 y 1995 y 18 entre 2000 y 2003. Estos diferentes patrones pueden ser utilizados para distinguir entre cepas de campo españolas del PRRSV y las tres cepas vacunales de tipo I usadas en España: AmervacPRRS®, Pyrsvac-183® y PorcilisPRRS®.

Bohoyo, F. et al., Póster presentado en la 4th Open Science Conference, organizada junto a la XXXI SCAR Science Week, en Buenos Aires (Argentina), del 3 al 6 de agosto de 2010., publicado en: MARENSSI, S. (ed.). 4th SCAR Open Science Conference - Antarctica: Witness to the Past and Guide to the Future. Submitted Abstracts. Cambridge: SCAR, 2010. CD-ROM

6 pages, 4 figures., Multichannel and high resolution seismic profiles from the central Scotia Sea and northern Weddell Sea show a sequence of seismic units interpreted to be the result of high-energy bottom currents. The seismic character of the units is indicative of active bottom flows, which developed extensive drifts under the influence of the Weddell Sea Bottom Water (WSBW) and the Antarctic Circumpolar Current (ACC). The opening of the connection between Jane Basin and the Scotia Sea is marked by a major regional unconformity that recorded a reorganization of bottom flows. The uppermost deposits are characterized by intensified bottom currents, which may reflect increased production of WSBW., The Spanish “Comisión Interministerial de Ciencia y Tecnología (CYCIT)” supported this research through Project ANT94-0020, ANT99-08, REN2001-2143/ANT and CGL2004-05646/ANT.

The Guadiana estuary, located in the south-western part of the Iberian Peninsula, is a narrow, bedrock-controlled estuary, characterized by a seasonal fluvial regime and mesotidal conditions. Bathymetric surveys, geophysical records (Side Scan Sonar, high-resolution seismics), surficial sediment sampling, fluvial discharge data, salinity and velocity measurements were integrated to decipher the influence of tidal currents on bedload sediment transport patterns during low fluvial discharge periods. Results evidence a landward change of dominant tidal transport direction, from ebb- to flood-current dominance. The southern (seaward) estuarine stretch shows mostly seaward-directed bedload transport patterns, related to ebb-current dominance close to the river mouth. Further upstream, morphological and hydrological evidences suggest a higher influence of flood currents. The estuarine stratification seems to control the observed flood-ebb asymmetry, as higher flood dominance during neap tides is related with the establishment of stratified conditions. However, the prevailing tidal pattern is not able to produce a reversal of estuarine dune asymmetry in widespread zones of the southern estuarine stretch. In contrast, intense, landward-directed sediment transport is evidenced in the northern estuarine stretch. Flood-current enhancement in the northern stretch is probably related with channel narrowing and, consequently, with channel section decrease 0

VI Congreso Geológico de España, 12-15 julio 2004, Zaragoza.-- 4 pages, 3 figures, A study of the contourite depositional model of the middle slope of the Gulf of Cadiz is presented within the regional morphosedimentary and stratigraphic framework of the continental margin. The margin is characterized by: a) a lack of submarine canyons (except in the Algarve margin); b) a large slope in which the middle slope is dominated by along-slope processes related to the Mediterranean Outflow Water (MOW) and generating the Contourite Depositional System (CDS) during the Pliocene and Quaternary; c) the dominance of down-slope processes across parts of the upper and lower slope and abyssal plain; d) the lack of true continental rise; and e) an active compressive structural context where the "Cadiz Allocthonous Unit" represents an unstable substratum for the late Miocene, Pliocene and Quaternary sedimentation. The CDS on the Gulf of Cadiz's middle slope comprises five major morphosedimentary sectors related to the progressive deceleration of the MOW, bathymetric stress on the margin, and the Coriolis force. The CDS of the Gulf of Cadiz can be interpreted as a mixed Contourite-turbidite system (a detached combined drift system), which has developed in a mid-slope setting. This is rather different from the principal contourite systems along parts of the Northwest Atlantic margins, where the along-slope processes are developed in a more distal part of the mixed system. There may be closer similarities with the drift systems along the NW Hebridean margin

The objectives of the present paper are the determination of the morphologic characteristics of the superficial Quaternary relict facies on the internal continental shelf in the Gulf of Cadiz, between Ayamonte and Huelva (southern Spain), their characterisation, and their evolution in the final phases of the last eustatic hemicycle. The study area extends from the mouth of the Guadiana River to the mouth of the Tinto-Odiel River, and from the 6 m isobath to the 56 m isobath. High-resolution seismic profiles (3.5 kHz and Geopulse, 175 J), sonographic profiles (SSS, 100 kHz), and bathymetric profiles (Echotrac sounder) were used in this study. Sediment samples were obtained using Van Veen and Shipek drags. Bathymetric, physiographic, lithologic and morphologic analyses were performed to determine the superficial sediment distribution, relict facies distribution, and thickness of the unconsolidated sediment cover. Analysis of the data obtained indicated that the relict facies beaches and coastal barriers associated with coastal spits located in the ancient outlets of the rivers. Relict facies were grouped into well-differentiated depths, indicating that their position on the continental shelf is influenced by the still-stands and the periods of rapid sea-level changes. The nature of the outcropping relict facies shows that their final configuration can be related to the shelf construction processes, as well as to the most important Holocene transgressive phases. Los objetivos de este trabajo son la determinación de las características morfológicas, la caracterización de las facies relictas cuaternarias superficiales y el estudio de su evolución con relación a las fases finales del último hemiciclo eustático en la plataforma continental interna del golfo de Cádiz, entre Ayamonte y Huelva. El área de estudio abarca desde la desembocadura del río Guadiana hasta la del río Tinto-Odiel y desde los 6 m hasta 56 m de profundidad. Se utilizó gran cantidad de material geofísico, en el que se encuentran perfiles sísmicos de alta resolución (3.5 kHz y Geopulse, 175 J), perfiles sonográficos y perfiles batimétricos, además de muestras de sedimentos obtenidas con dragas Van Veen y Shipek. Con esta información se han realizado análisis batimétricos, fisiográficos, litológicos y morfológicos, además de determinar la distribución de los sedimentos superficiales y de las facies relictas y de cuantificar la potencia de la cobertera sedimentaria. Con todos los datos obtenidos se ha determinado que las facies relictas son interpretadas como playas y cordones litorales asociados a flechas litorales situadas en las antiguas desembocaduras de los ríos. Las formas descritas están agrupadas en zonaciones batimétricas bien diferenciadas, lo que indica que su posición en la plataforma continental está influida por las paradas y etapas de movimiento rápido del nivel del mar. Las características de las facies relictas aflorantes indican que su configuración final puede estar relacionada con los procesos de edificación de la plataforma a partir de las mayores fases transgresivas holocenas. Instituto Español de Oceanografía

The role that the opening and deepening of the Drake Passage and the Scotia Sea played in the development of the first Cenozoic continental ice sheet in Antarctica and the onset of the Antarctic Circumpolar Current (ACC) during the Eocene-Oligocene Transition (EOT) is still uncertain. This limited knowledge stems from the poor age control of the separation of the different continental blocks leading to the opening of the Drake Passage; in fact, proposed ages for this opening range from 40 to 17 million years (Ma). Along with the progressive opening of Drake Passage, a number of small sedimentary basins developed in the southern Scotia Sea. These basins had a major impact on the establishment on deep-water circulation patterns due to their role as principal conduits for the exit cold Antarctic waters from the Weddell Sea (i.e., the Weddell Sea Deep Water: WSDW) and their interaction with the different fronts of the ACC in the Scotia Sea. In spite of this importance, the knowledge of the distribution and temporal variability of the water masses in the Scotia Sea is very limited. This PhD Thesis aims to: (1) reconstruct late Eocene to early Oligocene paleoenvironmental changes at the South Orkney Microcontinent (SOM) and their relation to the tectonic and climatic evolution of the Drake Passage-Scotia Sea; (2) reconstruct the recent deep-water sedimentation patterns in the western Scotia Sea to asses the paths and interactions between major bottom current patterns once the ACC and the WSDW were fully developed. These two objectives target two different temporal windows that represent the two end-member situations on the establishment of bottom currents around Antarctica, and their eventual links with climatic changes. To achieve these aims, we have conducted a suite of analysis in marine sediment cores recovered in the SOM (ODP Site 696B), and using geophysical and hydrographic datasets collected in the westernmost Scotia Sea basin (Ona Basin). Firstly, this PhD Thesis shows that during the late Eocene (~37.6–35.5 Ma) the SOM was still attached to the Antarctic Peninsula prior to rifting related to the opening of Powell Basin. From ~35.5–34.1 Ma, a shutdown in terrestrial input and the identification of a glauconitization processes indicates a continuous deepening and relative sealevel rise trend led by the rifting process and opening of the proto-Powell Basin. At the EOT (~34.1–33.6 Ma), major cooling and continental ice expansion to coastal and shelf areas was likely recorded at Site 696B by regressive phases bracketed within the overall sea-level trend recorded since ~35.5 Ma. The early Oligocene (~33.6–33.2 Ma) documents further deepening of the SOM in response to the continued rifting and opening of Powell Basin. During this last interval, deposition of organic-rich sediments was induced by enhancement of biological production, partially driven by upwelling. Major cooling across the EOT influenced the composition of terrestrial floras in our sediments record. A shift in terrestrial n-alkanes from relatively humid temperate forests in the late Eocene to dry and cool forests in the early Oligocene seems to indicate a weaker contribution of the terrestrial organic matter to the marine sediments. In addition, our results suggest that the opening of the proto-Powell Basin could have provided a shallow-water pathway for water flowing through the restricted Powell Basin towards the northern Weddell Sea, enhancing upwelling at the southern SOM shelf margin. Further, productivity variations since the EOT might have resulted from the combined effects of the Powell Basin opening and climate cooling. Our results further demonstrate that an integrated sedimentological, mineralogical and geochemical approach is required when interpreting glaucony-bearing deposits and related physico-chemical conditions. Only in such circumstances glaucony authigenesis can be used as a reliable paleoenvironmental indicator in Cenozoic Antarctic sediments (i.e., mature in situ vs. reworked sediments). Additionally, new insights into the nature of the mineral ‘glauconite’ have been provided. Particularly, it is proposed that glauconite must be assessed as mica-rich mica-smectite R3 interstratified mineral, while the pure end-member mica also having intrinsic K-deficient chemical characteristics (K+ ~ 0.8 apfu). Secondly, this PhD Thesis investigates the distribution of morpho-sedimentary features in Ona Basin as a proxy for documenting present-day oceanographic influence on the seafloor, once the Drake Passage and Scotia Sea basins have been fully opened. The southern margin of the basin can be regarded as a mixed/hybrid system containing abundant sediment drifts with channels and contourite moats and a lateral continuity interrupted by downslope morphologies. The northern abyssal setting comprises relatively homogeneous large sheeted drifts with superimposed sediment waves, mounded drifts, and several scattered erosive features, likely reflecting the more distinct influence of deepwater contourite processes. In the southern basin, tectonic features control the interaction between deepwater along- and downslope processes, as the westward flow of the WSDW is deflected, channelized, and intensified along its westward route. In contrast, an overall clockwise rotation of the WSDW flow, with the spatial and vertical variability of ACC fronts and WSDW affecting the distribution of bottom-current features around seamounts and/or structural highs is documented in the northern region. These results underscore the importance of sloping interphases in the water mass vertical structure, the degree of basin confinement, and the influence of local bathymetric elevations in sedimentation models of small sediment-starved oceanic basins., El papel desempeñado por la apertura y profundización del Paso de Drake y Mar de Scotia en el desarrollo de la primera capa de hielo Antártica a escala continental y el inicio de la Corriente Circumpolar Antártica (ACC) en la Transición Eoceno-Oligoceno (EOT), es objeto de debate. El factor limitante es el escaso control de edad de la separación de los diferentes bloques continentales que llevaron a la apertura del Paso de Drake; de hecho, las edades propuestas para la apertura varían entre 40 y 17 millones de años (Ma). La apertura progresiva del Paso de Drake propició el desarrollo de pequeñas cuencas sedimentarias en el sur del Mar de Scotia. La formación de dichas cuencas tuvo un gran impacto en el establecimiento de los patrones de circulación de aguas profundas, posibilitando la salida de aguas antárcticas frías a través del Mar de Weddell (i.e., agua profunda del Mar de Weddell: WSDW), así como su interacción con los diferentes frentes de la ACC en el Mar de Scotia. Pese a su relevancia, el conocimiento de la distribución regional y la variabilidad temporal de las masas de agua en el Mar de Scotia es muy limitado. Esta tesis doctoral tiene dos objetivos principales: (1) reconstruir los cambios paleoambientes en el Microcontinente de las Orcadas del Sur (SOM) y su relación con la evolución tectónica y climática del Paso de Drake -Mar de Scotia durante el Eoceno superior- Oligoceno; (2) reconstruir los patrones de sedimentación reciente en aguas profundas en la parte occidental del Mar de Scotia, y evaluar las rutas e interacciones entre las principales corrientes de fondo (ACC y WSDW) una vez desarrolladas completamente. Estos dos objetivos engloban dos ventanas temporales diferentes que representan las dos situaciones extremas de influencia de las corrientes de fondo alrededor de la Antártida, y sus eventuales vínculos con los cambios climáticos. Para lograr estos objetivos, se han llevado a cabo análisis en testigos de sedimentos marinos obtenidos en el SOM (Pozo ODP 696B), y de datos geofísicos e hidrográficos obtenidos en la Cuenca Ona, la cuenca más occidental del Mar de Scotia. En primer lugar, esta tesis indica que durante el Eoceno tardío (~37.6–35.5 Ma) el SOM estaba unido a la Península Antártica antes de la apertura de la Cuenca Powell. Desde ~35.5–34.1 Ma, la identificación de un proceso de glauconitización documenta un reducción de aporte terrígeno al SOM y una tendencia de ascenso relativo del nivel del mar guiada por la apertura de la proto-Cuenca Powell. En la EOT (~34.1–33.6 Ma), se identifican dos fases regresivas dentro de la tendencia general de ascenso relativo del nivel del mar, posiblemente relacionadas con el enfriamiento global y la expansión del hielo continental hacia zonas costeras antárticas. El Oligoceno inferior (~33.6–33.2 Ma) documenta una profundización adicional del SOM en respuesta al desarrollo de la apertura de la Cuenca Powell. Durante este último intervalo la sedimentación es rica en materia orgánica en respuesta a un incremento de la productividad biológica, en parte determinada por el establecimiento de un fenómeno de afloramiento costero. El enfriamiento durante la EOT condicionó la composición de floras terrestres. Nuestro registro sedimentario, de n-alcanos sugiere un cambio de bosques templados relativamente húmedos en el Eoceno superior a bosques secos y fríos en el Oligoceno inferior, acompañado de una disminución progresiva del aporte de materia orgánica terrestre. Además, nuestros resultados sugieren que la apertura de la proto-Cuenca Powell podría haber proporcionado una vía somera para un flujo de agua a través de la cuenca restringida hacia el norte del Mar de Weddell, estableciendo las condiciones para el desarrollo de un afloramiento costero en el margen sur de la plataforma del SOM. Asimismo, las variaciones de productividad desde el EOT podrían haber sido el resultado del efecto combinado de la apertura de la Cuenca Powell y el enfriamiento climático. Nuestros resultados, además, demuestran la necesidad de establecer un enfoque integrado (sedimentológico, mineralógico y geoquímico) al interpretar sedimentos glauconíticos y las condiciones fisicoquímicas relacionadas con su depósito. Solo bajo esas condiciones la autogénesis de glauconia puede utilizarse como un indicador paleoambiental en sedimentos antárticos cenozoicos. Además, se proporcionan nuevos avances en el conocimiento del mineral ‘glauconita’. En particular, se propone que la glauconita debe considerarse como un interestratificado mica-esmectita con orden R3, rico en mica, mientras que la mica pura del término extremo también tiene características químicas intrínsecas deficientes en K (K+ ~0.8 apfu). En segundo lugar, esta tesis doctoral investiga la distribución espacial de los rasgos morfo-sedimentarios superficiales en la Cuenca Ona, documentando así la influencia de las masas de agua profundas en el modelado del fondo marino, una vez abierto completamente el Paso de Drake y las cuencas del Mar de Scotia. El margen sur de la cuenca puede considerarse como un sistema mixto/híbrido con abundantes cuerpos y rasgos erosivos contorníticos con una gran extensión lateral, interrumpidos por morfologías perpendiculares al talud. La llanura abisal incluye extensos cuerpos contorníticos laminares relativamente homogéneos con ondas de sedimento superimpuestas, cuerpos contorníticos monticulares y diversos rasgos erosivos contorníticos, indicando una influencia mayor de las masas de agua de fondo en el suelo marino. En el sur de la cuenca, la tectónica es el factor de control en la interacción entre los procesos sedimentarios profundos longitudinales y transversales al margen continental, a medida que el flujo hacia el oeste del WSDW se desvía, canaliza e intensifica en su ruta. Por el contrario, en el norte de la cuenca se documenta la rotación en sentido horario del flujo del WSDW, así como una variabilidad espacial y vertical del WSDW y de los frentes de la ACC, afectando los patrones de sedimentación profundos alrededor de montes submarinos y altos estructurales. Estos resultados señalan la importancia de la estructura vertical de las masas de agua, la inclinación de las interfases, el grado de confinamiento de las cuenca, y la influencia de los altos batimétricos en los modelos de sedimentación de pequeñas cuencas oceánicas con escaso aporte sedimentario., Tesis Univ. Granada., Formación de Personal Investigador FPI (BES-2015-073989) from the Spanish Ministerio de Economía y Competitividad with the grant CTM2014-60451-C2-1-P, CTM2017-89711-C2-1-P