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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.

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

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 )