Evolución tectónica y morfoestructural reciente de la Península Byers (Antártida): evidencias sobre el desarrollo de las Islas Shetland del Sur y la Cuenca de Bransfield

[EN] Byers Peninsula forms the western extremity of the Livingston Island (Antarctica) in the continental South Shetland Block. This tectonic block is bounded by the South Shetland Trench to the north, the Bransfield back-arc basin to the south, and extends to the South Scotia Ridge on the east. Westwards it is connected to the Antarctic Plate by a broad deformation zone located at the southern end of the Hero Fracture Zone. In Byers Peninsula we analyzed more than 1,200 lineaments, and 359 fault planes from 16 sites, both in sedimentary and intrusive igneous rocks. Statistical analysis of lineaments and mesoscopic fractures, with a length varying between 31 and 1,555 m, shows a NW-SE maximum trend, with two NE-SW and ENE-WSW secondary maximums. Fault orientation analysis shows similar trends suggesting that most of the lineaments correspond to fractures. Due to the absence of striated faults and the lack of kinematic evidence on the regime in most of the analyzed faults we have used the Search Grid paleostress determination method. The results obtained allow us to improve and complete the data on the recent evolution of the South Shetland Block. In this complex geodynamic setting, Byers Peninsula has been subjected to NNW-SSE to NNE-SSW extension related to Bransfield Basine Antarcopening and NE-SW and NW-SE local compressions respectively associated to Scotia-Antarctic plate convergence and the South Shetland Trench subduction.[ES] La Península Byers se localiza en el extremo occidental de la Isla Livingston (Antártida) que pertenece al bloque continental de las Shetland del Sur. Este bloque tectónico está limitado al norte por la Fosa de las Shetland del Sur, al sur por la cuenca de trasarco de Bransfield, y hacia el este se extiende por la Dorsal Sur de Scotia. Hacia el oeste conecta con la placa Antártica a través de una amplia zona de deformación localizada en la prolongación meridional de la Zona de Fractura Hero. En este trabajo se han analizado conjuntamente más de 1.200 lineamientos, así como 359 planos de fallas en 16 estaciones en rocas sedimentarias e ígneas de la Península Byers. El análisis estadístico de los lineamientos y las fracturas a escala mesoscópica, con una longitud que oscila entre 31 y 1.555 m, muestran una orientación máxima NO-SE, con dos máximos secundarios de dirección NE-SO y ENE-OSO. El análisis de las fracturas muestra orientaciones similares que sugieren que gran parte de estos lineamientos están relacionados con fracturas. La ausencia de indicadores cinemáticos de calidad en la mayor parte de las fracturas sólo nos ha permitido aplicar el método de Redes de Búsqueda para el cálculo de paleoesfuerzos. Los resultados obtenidos son compatibles con los obtenidos en otros sectores del Bloque de las Shetland del Sur. En este complejo contexto geodinámico, la Península Byers ha estado sometida a extensión NNW-SSE/ NNE-SSW ligada a la apertura de la cuenca de Bransfield, así como a compresión local NE-SO y NO-SE asociada respectivamente a la convergencia entre las placas Scotia y Antártica, y a la subducción en la Fosa de las Shetland del Sur.Financial support for this work was provided by the research projects REN2001-0643, CGL2005-03256 and CGL2007-28812-E/ANT of the Spanish R & D National Plan.Peer reviewe

Mantle flow and deep electrical anisotropy in a main gateway: MT study in Tierra del Fuego

Asthenospheric mantle flow drives lithospheric plate motion and constitutes a relevant feature of Earth gateways. It most likely influences the spatial pattern of seismic velocity and deep electrical anisotropies. The Drake Passage is a main gateway in the global pattern of mantle flow. The separation of the South American and Antarctic plates since the Oligocene produced this oceanic and mantle gateway connecting the Pacific and Atlantic oceans. Here we analyze the deep crustal and upper mantle electrical anisotropy of its northern margin using long period magnetotelluric data from Tierra del Fuego (Argentina). The influence of the surrounding oceans was taken into account to constrain the mantle electrical conductivity features. 3D electrical models were calculated to fit 18 sites responses in this area. The phase tensor pattern for the longest periods reveals the existence of a well-defined NW-SE electrical conductivity anisotropy in the upper mantle. This anisotropy would result from the mantle flow related to the 30 to 6 Ma West Scotia spreading, constricted by the subducted slab orientation of the Pacific plate, rather than the later eastward mantle flow across the Drake Passage. Deep electrical anisotropy proves to be a key tool for a better understanding of mantle flow.This work was supported through projects CTM2014-60451-C2-02/01 and CTM2017-89711-C2-2/1-P from Ministry of Science, Innovation and Universities of Spain and the RNM-148 from Junta de Andalucía (Spain)

Evolución paleogeográfica, paleoclimática y paleoambiental de la costa meridional de la Península Ibérica durante el Pleistoceno superior. El caso de la Cueva de Nerja (Málaga, Andalucía, España).

Presentamos los cambios paleogeográficos, paleoclimáticos y paleoambientales acontecidos en la costa mediterránea meridional de la Península Ibérica durante el Pleistoceno superior y comienzos del Holoceno, analizados a partir de la cartografía batimétrica y geomorfológica de la franja costera submarina del este de Málaga, del registro de la temperatura de la superficie del mar de Alborán obtenido en el sondeo MD95-2043 y de los datos radiométricos, paleobiológicos y arqueológicos proporcionados por el registro estratigráfico del yacimiento de la Cueva de Nerja (Nerja, Málaga, España). Este registro sedimentario, con doce etapas de erosión y sedimentación, se emplazó en las salas más exteriores de la cavidad entre los estadios finales del Pleistoceno superior y el Holoceno medio en un lapso cronológico comprendido entre 29600 y 3940 años cal BP. Durante ese tiempo, la posición del mar estuvo situada a diferentes cotas por debajo de su posición actual, lo que condicionó la emersión de una franja costera de diferente amplitud a lo largo del tiempo, en la que las poblaciones humanas que habitaron la Cueva de Nerja desarrollaron sus actividades. Igualmente se observa una notable variación en la temperatura superficial del agua del mar y una serie de cambios en la composición de la vegetación y la fauna de vertebrados e invertebrados explotadas por los habitantes de la Cueva de Nerja. En este contexto cabe señalar la presencia en el registro de la cavidad de diferentes especies marinas de latitudes septentrionales y aguas más frías, actualmente ajenas al Mediterráneo

Occurrence of whale barnacles in Nerja Cave (Málaga, southern Spain): Indirect evidence of whale consumption by humans in the Upper Magdalenian

A total of 167 plates of two whale barnacle species (Tubicinella majorLamarck, 1802 and Cetopirus complanatusMörch, 1853) have been found in the Upper Magdalenian layers of Nerja Cave, Mina Chamber (Maro, Málaga, southern Spain). This is the first occurrence of these species in a prehistoric site. Both species are specific to the southern right whale Eubalena australis, today endemic in the Southern Hemisphere. Because of Antarctic sea-ice expansion during the Last Glacial Period, these whales could have migrated to the Northern Hemisphere, and reached southern Spain. Whale barnacles indicate that maritime-oriented forager human groups found stranded whales on the coast and, because of the size and weight of the large bones, transported only certain pieces (skin, blubber and meat) to the caves where they were consumed

Towards 3D databases and harmonized 3D models at IGME-CSIC

IGME-CSIC has a highly relevant geological and geophysical database that includes a continuous digital geological cartography at 1:50000; 1:200000 and 1:1000000 scales and a fair amount of geophysical data: gravity, magnetic, well-logs in tiff and LAS format, seismic lines in tiff and SEG-Y format, borehole and petrophysical data, together with other geophysical and geological studies. Since the 2004, an important effort has been done to undertake 3D geological and geophysical modelling ranging from local studies (mineral exploration or CO2 storage sites) to regional geology for a better understanding of the subsurface structure and its geodynamic evolution as a base for other studies on natural hazards or mineral resources. These studies were ¿stand alone¿ and now IGME is designing a new strategy. It includes the available data and models harmonization (stratigraphy sequences, structural interpretations, faults distribution, seismic velocity models, spatial distribution of physical properties such as density and magnetic susceptibility, workflows, methodologies, evaluation of uncertainties, visualization, etc.) to comply with the FAIR (Findable, Accessible, Interoperable and Reusable) data standardization. In this way, the new 3D models will be easily integrated and available from the databases. This strategy includes collaboration with the Bureau de Recherches Géologiques et Minières of France (BRGM) and Laboratório Nacional de Energia e Geologia of Portugal (LNEG) in order to harmonize the Spanish geological data and models with their neighbours across national borders. The first step is being done in the framework of GeoERA projects. Plain-language Summary IGME-CSIC owns a large database that includes a highly valuable geological and geophysical data and geophysical studies containing the interpretation of some of the data of Spain (onshore and offshore) Since 2004 the authors of this work have been working in 3D geological and geophysical modelling that includes local (mineral exploration or CO2 storage sites) and regional studies. The goal is to improve our understanding of the subsurface structures and processes as a base for deepening our knowledge in how the natural hazards occur, how to improve the exploration for mineral resources, etc. These studies were made ad hoc within different projects and now IGME-CSIC is designing a workflow to harmonize these models in order to comply with the FAIR (Findable, Accessible, Interoperable and Reusable) data standardization so the models will be available to being used beyond the initial objectives that generated their creation. This strategy includes collaboration with other European institutions like the Bureau de Recherches Géologiques et Minières of France (BRGM) and Laboratório Nacional de Energia e Geologia of Portugal (LNEG) in order to harmonize the models across national borders. The first step is already being done in the framework of the GeoERA projects

Palaeolithic – Epipalaeolithic Seapeople of the Southern Iberian coast (Spain): an overview

The significance of coastal areas to human survival and expansion on the planet is undeniable. Their ecological diversity and their use as communication routes are some of their most distinctive qualities. However, the evidence of exploitation of these resources has had an uneven preservation, which is limited to certain regions and more recent events, mainly sites with deposits from the Upper Pleistocene and Holocene. This paper analyses the data available on the use of marine resources between MIS 6 and MIS 1 (c. 150 – 9 ka BP) in Southern Iberia, one of the first regions in Europe where marine faunal remains were discovered, in archaeological deposits from Middle and Upper Palaeolithic. Therefore their presence here has not been a criterion of separation between Neanderthals and Modern humans, but it may be relevant to analyze changes in the use of small preys or assess the economic diversification in regions where this came at an early date. One of the aims of this study was to evaluate the diachronic trends of the different palaeobiological marine remains recovered from coastal and inland archaeological sites. This preliminary extract indicates that the analysis of marine resource exploitation cannot be classed as a mere listing of palaeobiological remains. This information may be relevant in the initial stages, but it is insufficient in the evaluation of techno-economic and sociocultural transformations that can be linked to the use of marine resources. The distribution of palaeobiological marine remains differs over time and also according to the location of the sites with respect to the changing coastline throughout the period analysed. The known sites that preserve evidence of the use of marine resources as a food source are located mainly on the present coastline, or in a range of less than 10 km. Invertebrate remains have been identified in most, whereas fish, bird and mammal bones only in certain sites. Molluscs used as ornaments or pendants and containers are more widely distributed than other species used for food. Because these data must be contextualized, bone and stone tools linked to the exploitation of the marine environment have been added to the palaeobiological information, drawing inferences based on the analogy between both ethnologically and archaeologically documented tools. Symbolic expressions have also been studied, given the significant number of painted and engraved marine fauna depictions, specifically pisciforms and mammals, found in southern Iberia. Lastly, available molecular data has also been evaluated, from the results of isotope analysis on human remains. This combination of palaeobiological, techno-economic, graphic-symbolic and molecular data, allows a first assessment of the use of marine resources in the region

Utilización de metodologías activas de enseñanza para el aprendizaje de las matemáticas, centradas en el estudiante y desarrolladas en el espacio innovador de una hiperaula

La inauguración de la hiperaula de la Facultad de Educación-CFP (UCM) en abril de 2019 y su prioridad de uso para el Máster en Formación del Profesorado de Educación Secundaria, Bachillerato, Formación Profesional y Enseñanza de Idiomas durante el curso académico 2019-2020, supone un marco experimental absolutamente novedoso. Estas circunstancias permiten a la responsable del proyecto y a varios profesores participantes en el mismo, algunos de ellos docentes en el mencionado Máster y pertenecientes a diferentes Departamentos y Facultades de la UCM, así como a varios alumni y personal de administración y servicios implicados en el proyecto, utilizar este innovador espacio para la enseñanza de la asignatura de "Innovación docente e iniciación a la investigación educativa" (especialidad de matemáticas del Máster en Formación del Profesorado), empleando para ello metodologías activas de enseñanza centradas en el estudiante

Bathymetry and geological setting of the Drake Passage (Antarctica)

IX Congreso Geológico de España, Huelva, Septiembre 2016The Drake Passage is an oceanic gateway of about 850 km width located between South America and the Antarctic Peninsula that connects the southeastern Pacific and the southwestern Atlantic oceans and is an important gateway for mantle flow, oceanographic water masses, and migrations of biota. This gateway developed within the framework of geological evolution of the Scotia Arc. As a consequence of this and subsequent submarine processes, this region shows a varied physiography. The new detailed map in the Drake Passage region is mainly founded on a compilation of precise multibeam bathymetric data obtained on cruises between 1992 and 2014, and covers the area between parallels 52ºS and 63ºS and meridians 70ºW and 50ºW. The new map that we present is based in a DTM with 200 m cell resolution of the seafloor in Drake Passage that permits identification of the main seafloor features and the map includes additional useful geological information. This work constitutes an international cooperative effort and is part of IBCSO project (International Bathymetric Chart of the Southern Ocean), under the SCAR umbrella.Instituto Geológico y Minero de España, EspañaBritish Antarctic Survey, Reino UnidoDepartamento de Geodinámica, Universidad de Granada, EspañaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaInstituto Andaluz de Ciencias de la Tierra, Universidad de Granada, EspañaJet Propulsion Laboratory M/S 300-323, Estados UnidosAlfred Wegener Institute, AlemaniaKorea Polar Research Institute, CoreaDepartamento de Geología y Geoquímica, Universidad Autónoma de Madrid, EspañaLamont-Doherty Earth Observatory, Columbia University, Estados Unido

Subsurface Geophysics and Geology (GEOFSU

[EN] The geophysics line at the IGME began in 1927 as a Geophysics Sectiondedicated to subsurface exploration. During all this time, it has been developed in order to support and give expert service in all IGME’s activities both as a geological service and public research institution, as well as a research and development work itself. On the other hand, in recent years the IGME has promoted a line of research aimed at the characterization and 3D modeling of geological structures and formations, the development of dedicated software and the evolution and sophistication of computer equipment. The new scenario of incorporation of the IGME to the CSIC as a national reference center in the field of Earth Sciences has allowed the establishment of the GEOFSUB Research Group (Subsurface Geophysics and Geology). It is constituted by 21 members who had been collaborating regularly of the IGME former scientific-technic areas Geophysics and remote sensing (Área de Geofísica y Teledetección) and Subsurface geology and 3D geological modelling (Área de Geología del Subsuelo y Modelización Geológica 3D). Our main differentiating element is our extensive knowledge of geophysical and geological techniques, which allows us to characterize the subsoil in an optimal waPeer reviewe

Maritime-oriented foragers during the Late Pleistocene on the eastern costa del sol (Southeast Iberia): Cueva Victoria (Málaga, Spain)

The Mediterranean coast of Spain is marked by several clusters of Palaeolithic sites: to the south of the Pyrenees, in the area around the Ebro River, in the central part, and on the south coast, one of the southernmost regions in Europe. The number of sites is small compared with northern Iberia, but like that region, the Palaeolithic occupations are accompanied by several rock art ensembles. The archaeological material (both biotic and abiotic resources) and radiocarbon dates presented here were obtained during archaeological fieldwork of professor J. Fortea in the Late Pleistocene deposits in Cueva Victoria, located near the modern coastline and about 150 km north of the Strait of Gibraltar. In the three occupation phases, marine resources were acquired by shell-fishing (focusing almost exclusively on the clam Ruditapes decussatus), fishing, and the use of beached marine mammals. This contrasts with the limited data about the exploitation of terrestrial resources by hunting and gathering animals and plants. The study is completed by the study of artefacts (lithic and bone industry and objects of adornment) that help to understand the subsistence strategies of the cave occupants and enable a comparison with other groups inhabiting the Mediterranean coasts of the Iberian Peninsula during Greenland Interstadial 1, between ca. 15.1 and 13.6 cal BP.This work was supported by the University of Salamanca GIR PREHUSAL, the Ministry of Science and Innovation-Spanish Government (PaleontheMove-PID2020-114462GB-I00), the Universidad Nacional de Educación a Distancia (Madrid) and Dirección General de Universitat, Investigacio i Ciencia of the Valencian Regional Government (Project Aico/2020/97).Peer reviewe