Nuevos datos cronoestratigráficos de la Fm. Marismas (Bajo Guadalquivir)

La Formación Marismas forma la parte superior del relleno sedimentario del sector SW de la cuenca del Guadalquivir. Los datos previos sobre el sondeo Lebrija, indicaban que la parte más alta de esta formación tenía edades de hasta 9.6 kyr BP y en la parte inferior eran cercanas o fuera del rango del radiocarbono, pero posterior a la reversión Brunhes-Matuyama. En este trabajo se aportan 17 nuevas dataciones realizadas mediante racemización de aminoácidos en valvas de ostrácodos en este mismo sondeo, con el fin de completar la cronología y el modelo de edad de la parte superior e inferior de la Fm Marismas. El resultado indica que el tramo situado por debajo del metro 56, arroja edades que oscilan entre 164685±14110 y 202830±30255, que se correlacionan con los estadios isotópicos marinos MIS 6-7 del Pleistoceno medio, edad sensiblemente más baja a las inferidas para esta formación en otros puntos de la Cuenca del bajo GuadalquivirEste trabajo se ha realizado dentro del proyecto Guadaltyc (Impacto del clima y la tectónica en el registro sedimentario de la Cuenca del Guadalquivir, (CGL2012-30875).Peer Reviewe

Late Holocene climate variability in the southwestern Mediterranean region: an integrated marine and terrestrial geochemical approach

10 páginas, 5 figuras, 1 tabla.A combination of marine (Alboran Sea cores, ODP 976 and TTR 300 G) and terrestrial (Zoñar Lake, Andalucia, Spain) geochemical proxies provides a high-resolution reconstruction of climate variability and human influence in the southwestern Mediterranean region for the last 4000 years at inter-centennial resolution. Proxies respond to changes in precipitation rather than temperature alone. Our combined terrestrial and marine archive documents a succession of dry and wet periods coherent with the North Atlantic climate signal. A dry period occurred prior to 2.7 cal ka BP – synchronously to the global aridity crisis of the third-millennium BC – and during the Medieval Climate Anomaly (1.4–0.7 cal ka BP). Wetter conditions prevailed from 2.7 to 1.4 cal ka BP. Hydrological signatures during the Little Ice Age are highly variable but consistent with more humidity than the Medieval Climate Anomaly. Additionally, Pb anomalies in sediments at the end of the Bronze Age suggest anthropogenic pollution earlier than the Roman Empire development in the Iberian Peninsula. The Late Holocene climate evolution of the in the study area confirms the see-saw pattern between the eastern and western Mediterranean regions and the higher influence of the North Atlantic dynamics in the western Mediterranean.Projects LIMNOCLIBER REN 2003-09130- C02-02, CALIBRE CGL 2006-13327-c04/CLI, CGL-2006-2956- BOS, CGL2009-07603 (MICINN), 200800050084447 (MARM) and RNM 05212 (Junta de Andalucía), we also thanks Projects GRACCIE (CSD2007- 00067) and CTM2009-07715 (MICINN), Research Group 0179 (Junta de Andalucía) and the Training- Through-Research Programme.Peer reviewe

Environmental magnetic fingerprinting of anthropogenic and natural atmospheric deposition over southwestern Europe

Here we present an environmental magnetic study of atmospheric deposition collected by a multi-site network in Spain that covers fourteen locations representative of urban, industrial, agricultural, and natural environments across southwestern Europe. We have combined magnetic methods with scanning electron microscopy and geochemical data to characterize the magnetic mineral assemblages of particulate matter across different types of sites and phenomenological scenarios, and to unravel their environmental significance in terms of the most important anthropogenic and natural components of atmospheric deposition. Our results enable identification of two magnetite/maghemite components of anthropogenic origin, derived mostly from vehicular traffic, plus a hematite component associated with a baseline supply of north African dust, in all the studied sites regardless of their type. The ubiquitous presence of anthropogenic magnetite/maghemite particles in pristine natural envi-ronments, albeit in lower concentrations, point to their arrival from neighbouring urban areas through atmo-spheric mixing processes. Samples including particulate matter deposited during distinctively intense periods of north African dust supply are characterized by a fourth component, represented also by coarser-grained he-matite, that is likely derived from a different source area within the Sahara Desert. The concomitant increase observed in these cases in the amounts of magnetite/maghemite particles suggests strongly that part of the magnetite/maghemite load attributed to anthropogenic sources for the rest of the phenomenological scenarios is aeolian in origin. This seems to explain the overall moderate correlation observed between magnetite/maghe-mite contents and proxies for vehicular traffic, and demonstrates the need for caution when interpreting envi-ronmental magnetic proxies for magnetite/maghemite abundances in terms of anthropogenic loads. This is especially the case in southern European cities where a steady supply of north African dust occurs throughout most of the year. Our results show a good correlation between hematite abundances and geochemical proxies for north African dust, which collectively delineate broad maxima during the summer and large peaks during distinctive dust breakouts. Thus, environmental magnetic proxies of hematite abundances can be used to monitor the contribution of natural sources to atmospheric deposition.This study was funded by the Spanish Agencia Estatal de Investigación and the European Funds for Regional Development (AEI/FEDER, UE) via the DONAIRE (CGL2015-68993-R) project. XZ and DH were supported by Australian Council Discovery Project DP200100765

Early Pliocene climatic optimum, cooling and early glaciation deduced by terrestrial and marine environmental changes in SW Spain

The Pliocene is a key period in Earth's climate evolution, as it records the transition from warm and stable conditions to the colder and more variable glaciated climate of the Pleistocene. Simultaneously, climate became more seasonal in the Mediterranean area, and Mediterranean-type seasonal precipitation rhythm with summer drought established. These climatic changes presumably had significant impacts on terrestrial environments. However, the response of terrestrial environments to such climate changes is still not fully understood due to the lack of detailed studies dealing with this period of time. In this study, multiproxy analyses of continuous core sampling from La Matilla (SW Spain) shows detailed and continuous record of pollen, sand content and abundance of benthic foraminifer Bolivina spathulata to describe paleoenvironmental and paleoclimate trends during the early Pliocene. This record shows warmest, most humid climate conditions and highest riverine nutrient supply at ~ 4.35 Ma, coinciding with the Pliocene climatic optimum and high global sea level. A climate cooling and aridity trend occurred subsequently and a significant glaciation occurred at ~ 4.1–4.0 Ma, during a period known by very little terrestrial evidence of glaciation. Our multiproxy data thus indicate that terrestrial and marine environments were significantly variable during the early Pliocene and that major glaciation-like cooling occurred before the intensification of northern hemisphere glaciation at the beginning of the Pleistocene (~2.7 Ma). This major climate cooling and aridity maxima between 4.1 and 4.0 Ma is independently validated by a coeval sea-level drop (third order Za2 sequence boundary). This sea level drawdown is supported by enhanced coarse sedimentation and minima in riverine nutrient supply, showing paired vegetation and sea-level changes and thus a strong land-ocean relationship. This study also shows that long-term climatic trends were interrupted by orbital-scale cyclic climatic variability, with eccentricity, obliquity and precession acting as the main triggers controlling climate and environmental change in the area.Peer ReviewedPostprint (author's final draft

Contourite stratigraphic models linked to the light intermediate versus dense deep Mediterranean water flow regime variations (Alboran Sea, SW Mediterranean)

21 pages, 16 figures, 3 tables.-- Data availability: Data supporting this study are openly available from DIGITAL.CSIC at doi: 10.20350/digitalCSIC/15507Several water masses are involved in the circulation of oceans, their bottom layers impacting on sedimentation through contourites. The majority of palaeoceanographic studies on regional contourites are performed for one water mass despite that their joint study would offer relevant clues to understand past ocean and climate interaction. This works presents for the first time a an analysis about the impact of the Light Intermediate Mediterranean (LMW) and Dense Deep Mediterranean (DMW) bottom currents on the sedimentation in the Alboran Sea (SW Mediterranean) and its paleoceanographic significance in response to climatic oscillations from the last glacial period to the Holocene. To do this, an integration of chronostratigraphical, sedimentological, and compositional data is carried out from contourites formed by those water masses. That integration enable us to define three distinct contourite stratigraphic models. (I) The contourite terrace model, characterized by coarse-grained contourites, which is an archive of the interplay between the high-energy Atlantic Water-LMW interface and glacioeustasy from the Younger Dryas (YD) to the Holocene. (II) The contourite drift models, which are archives of rapid ocean-climate coupled fluctuations since 29.5 kyr. They comprise coarse-grained contourites formed by a relatively fast LMW and fine-grained contourites formed by a relatively weak DMW, except for the Heinrich Stadials HS3 to HS1 and YD when coarse-grained contourites were deposited. (III) The contourite/turbidite mixed model represents another archive of DMW and glacioeustasy interplay from the end of the late Pleistocene to Holocene. That contourite stratigraphy allows us to infer for the first time the relative variability of the LMW versus DMW flow regimes, which records differences and similarities. The similarities indicate that the LMW and DMW fluctuations occur in parallel at millennial and centennial time scales. The differences refer to the overall higher velocity of LMW versus DMW; the magnitude changes in velocities that are lower for LMW and higher for DMW; the recognition of three short ventilation events (a, b, c) during HS1 and HS2 for only DMW; and the distinct LMW and DMW responses to the onset of glacial conditions and return to interglacial conditions during the HSs, YD and Holocene cold periods. The proposed contourite stratigraphic models can be applied for other areas in the Mediterranean margins to identify and correlate the LMW and DMW palaeoceanographic events throughout this sea. The findings suggest that the different water masses that make up the water column must be seriously considered to fully understand palaeoceanographic and palaeoclimatic studies based on contourites. This is because their distinct impact on sedimentation may provide new insights into their different palaeoceanographic responses to rapid climatic oscillations and their triggering mechanismsWe are also grateful for the ‘Severo Ochoa Centre of Excellence’ accreditation of ICM-CSIC (CEX2019-000928-S)Peer reviewe

Understanding the complex geomorphology of a deep sea area affected by continental tectonic indentation: The case of the Gulf of Vera (Western Mediterranean)

19 pages, 11 figures, 1 table, supplementary data https://doi.org/10.1016/j.geomorph.2022.108126.-- Data availability: Casas, D., & UTM-CSIC. (2018). FAUCES-1 Cruise, RV Sarmiento de Gamboa [Data set]. UTM-CSIC. doi: 10.20351/29SG20170925 Comas, M. & UTM-CSIC. TOPOMED-GASBATS. Cruise, RV Sarmiento de Gamboa [Data set]. UTM-CSIC.doi: 10.20351/29SG20120517We present a multidisciplinary study of morphology, stratigraphy, sedimentology, tectonic structure, and physical oceanography to report that the complex geomorphology of the Palomares continental margin and adjacent Algerian abyssal plain (i.e., Gulf of Vera, Western Mediterranean), is the result of the sedimentary response to the Aguilas Arc continental tectonic indentation in the Eurasian–Africa plate collision. The indentation is imprinted on the basement of the margin with elongated metamorphic antiforms that are pierced by igneous bodies, and synforms that accommodate the deformation and create a complex physiography. The basement is partially covered by Upper Miocene deposits sealed by the regional Messinian Erosive Surface characterized by palaeocanyons that carve the modern margin. These deposits and outcropping basement highs are then covered and shaped by Plio-Quaternary contourites formed under the action of the Light Intermediate and Dense Deep Mediterranean bottom currents. Even though bottom currents are responsible for the primary sedimentation that shapes the margin, 97% of this region's seafloor is affected by mass-movements that modified contourite sediments by eroding, deforming, faulting, sliding, and depositing sediments. Mass-movement processes have resulted in the formation of recurrent mass-flow deposits, an enlargement of the submarine canyons and gully incisions, and basin-scale gravitational slides spreading above the Messinian Salinity Crisis salt layer. The Polopo, Aguilas and Gata slides are characterized by an extensional upslope domain that shapes the continental margin, and by a downslope contractional domain that shapes the abyssal plain with diapirs piercing (hemi)pelagites/sheet-like turbidites creating a seafloor dotted by numerous crests. The mass movements were mostly triggered by the interplay of the continental tectonic indentation of the Aguilas Arc with sedimentological factors over time. The indentation, which involves the progressively southeastward tectonic tilting of the whole land-sea region, likely generated a quasi-continuous oversteepening of the entire margin, thus reducing the stability of the contourites. In addition, tectonic tilting and subsidence of the abyssal plain favoured the flow of the underlying Messinian Salinity Crisis salt layer, contributing to the gravitational instability of the overlying sediments over large areas of the margin and abyssal plainThis research has been funding by the Spanish projects: DAMAGE (CGL2016-80687-RAEI/FEDER) and FAUCES (CTM2015-65461-C2-1-R); and the Junta de Andalucía projects: RNM-148 (AGORA) P18-RT-3275 and PAPEL (B-RNM-301-UGR18). [...] This work acknowledges to IGCP 640 - S4LIDE (Significance of Modern and Ancient Submarine Slope LandSLIDEs), and to the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S

Research Group on Sedimentary Record of Climatic Changes– SERCC

[EN] SERCC was created at the end of 2021 in response to the recent incorporation of the IGME as a National Centre of the Spanish Research Council (CSIC) and the need to converge to CSIC´s research organization, which is structured on Research Groups as basic units. SERCC is composed of 11 persons (6 Staff Scientists – 3 of them recently promoted to Scientific Researchers, 4 Specialized Technicians and 1 Predoctoral Student), and focuses on the imprint of past climate changes on the characteristics and properties of the sedimentary record, accumulated both in marine and continental realms.Peer reviewe

The Marboré Symphony: music for the deglaciation and Holocene in the central Pyrenees

20th Congress of the International Union for Quaternary Research (INQUA), Dublín, 2019Geological sequences have been used as the main basis for musical pieces both as inspiration for musicians and as raw materials (geochemical data, stratigraphic logs, cycles and frequencies) for compositions produced by computer programs. Telling our stories of Quaternary changes with music presents an opportunity to reach a wider audience and to integrate art and science. Here we present an example of how to compose music from Quaternary lake sequences and illustrate in a new way the main changes in the Pyrenean landscapes since deglaciation. The creation of this music was undertaken within the framework of the REPLIM project, an INTERREG- POCTEFA – project aimed to create a network of climate change observatories on lakes and wetlands in the Pyrenees. Based on the sediment sequence from Marboré Lake (42°41′44.27″N, 0° 2′24.07″E, 2612 m a.s.l), we have selected lithological, compositional and pollen data (Leunda et al, 2017; Oliva et al., 2018) to represent the main changes in the lake and the region during the last 15000 years. To transform the geological data into musical notes, we have used a similar approach than in previous experiences (Simon et al, 2015) but in this case, notes were assigned to compositional range intervals and the tempos were defined using sediment accumulation rates. Different melodies and instruments were assigned at each data set: TOC and Br/Ti as lake bioproductivity, selected pollen data for vegetation dynamics in the valleys, Si/Ti as sediment influx and Pb/Ti as anthropogenic impact. An electronic version of the Marbore Symphony was created by computer software based on the raw data. The music group O’Carolan (http://www.ocarolanfolk.com) transformed the electronic version into a six minutes long acoustic version. The Symphony premiered in the town of Bielsa on December 14th, 2018. The Marboré music project has served to increase citizenship awareness about climate change in the Pyrenees and provided a new tool to better communicate past and future changes in the landscapesInstituto Pirenaico de Ecología, EspañaUniversidad de Zaragoza, EspañaGrupo O´Carolan, EspañaInstituto Geológico y Minero de España, EspañaUniversidad Autonoma de Madrid, EspañaUniversidad del Pais Vasco, Españ

Guadalquivir Basin

Cap. 2.2. Guadalquivir Basin, páginas 40-59.Instituto Geológico y Minero de España, EspañaUniversidad de Salamanca, EspañaUniversitar de Barcelona, EspañaUniversitat Politècnica de Barcelona, EspañaGas Natural Fenosa, EspañaDepartamento de Ciências da Terra, Universidade de Coimbra, PortugalPeer reviewe

New discoveries of mud volcanoes on the Moroccan Atlantic continental margin (Gulf of Cádiz): morpho-structural characterization

10th International Conference on Gas in Marine Sediments, 6-11 September 2010, Listvyanka, RussiaDuring the MVSEIS-08 cruise of 2008, ten new mud volcanoes (MVs) were discovered on the offshore Moroccan continental margin (Gulf of Cádiz) at water depths between 750 and 1,600 m, using multibeam bathymetry, backscatter imagery, high-resolution seismic and gravity core data. Mud breccias were recovered in all cases, attesting to the nature of extrusion of these cones. The mud volcanoes are located in two fields: the MVSEIS, Moundforce, Pixie, Las Negras, Madrid, Guadix, Almanzor and El Cid MVs in the western Moroccan field, where mud volcanoes have long been suspected but to date not identified, and the Boabdil and Al Gacel MVs in the middle Moroccan field. Three main morphologies were observed: asymmetric, sub-circular and flat-topped cone-shaped types, this being the first report of asymmetric morphologies in the Gulf of Cádiz. Based on morpho-structural analysis, the features are interpreted to result from (1) repeated constructive (expulsion of fluid mud mixtures) and destructive (gravity-induced collapse and submarine landsliding) episodes and (2) interaction with bottom currentsDivisión de Geología Marina, Instituto Geológico y Minero de España, EspañaCentro Oceanográfico de Málaga, Instituto Español de Oceanografía, EspañaFacultad de Ciencias del Mar, Universidad de Cádiz, EspañaFacultad de Ciencias Geológicas, Universidad Complutense de Madrid, Españ