Person: Martín Chivelet, Javier
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First Name
Javier
Last Name
Martín Chivelet
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Estratigrafía
Identifiers
89 results
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Now showing 1 - 10 of 89
- Project number: 245
Item Aplicación didáctica mediante virtualización de afloramientos geológicos por medio herramientas digitales de muy alta resolución(2022) García Lorenzo, María De La Luz; Abati Gómez, Jacobo; Álvarez Sierra, María De Los Ángeles; Ancochea Soto, Eumenio; Arribas Mocoroa, María Eugenia; Arroyo Rey, Xabier; Benito Moreno, María Isabel; Campos Soto, Sonia; Castiñeiras García, Pedro; Crespo Feo, María Elena; Fernández Barrenechea, José María; García Romero, Emilia; Granja Bruña, José Luis; Huertas Coronel, María José; Ignacio San José, Cristina de; López De Andrés, María Sol; Martín Chivelet, Javier; Martínez Santos, Pedro; Montero González, Esperanza; Muñoz Martín, Alfonso; Orejana García, David; Pieren Pidal, Agustín Pedro; Piña García, Rubén; Sánchez Donoso, Ramón; Suárez González, Pablo; Pertuz Dominguez, AlejandroTras la situación sanitaria del curso 2019-2020 y a través del Proyecto INNOVA Gestión 223 de la convocatoria del año 2020-2021, la Facultad de Ciencias Geológicas ha adquirido una herramienta para la virtualización de afloramientos geológicos. Durante el curso 2020-2021 se ha virtualizado una salida de campo de cada uno de los grados que se imparten en la Facultad, Grado en Geología y Grado en Ingeniería Geológica. Además, la mayor parte de la actividad de campo de este curso tendrá lugar durante el mes de mayo, por lo que los profesores van a poder realizar la virtualización de sus salidas de campo mientras realizan la salida presencial con los estudiantes, o incluso en algunas asignaturas los propios estudiantes van a ser los responsables de la virtualización de las mismas. Por ello, la herramienta GIGAPAN no sólo es de elevada utilidad en momentos en los que las restricciones de movilidad impiden la realización del campo sino que también permiten aplicar metodologías docentes invertidas durante la realización de los campamentos. De este modo los estudiantes pasan a tener un papel activo en relación a su proceso de aprendizaje. La herramienta GIGAPAN permite que se combinen imágenes fotográficas de megapíxeles de alta resolución para crear imágenes panorámicas de gigapíxeles que luego se pueden explorar a muchas escalas haciendo zoom y visión panorámica. Los GigaPans son gigapíxeles panorámicos, imágenes digitales con billones de píxeles. Gigapan crea panorámicas enormes, para conseguir elevado detalle con mucha nitidez. Además de proporcionar una experiencia de aprendizaje alternativa, estos recursos permiten una visita 'virtual' que puede ser una herramienta de aprendizaje útil en cualquier escenario docente. La utilidad del material generado tiene validez más allá de la pandemia, ya que puede ser utilizado por los estudiantes en el estudio de las asignaturas de la titulación, con un enorme potencial didáctico hasta ahora poco explorado. Hasta la fecha el GIGAPAN se ha venido utilizando con cámaras personales de profesores de la Facultad, por lo que se hace necesario completar esta herramienta con una cámara compatible con el módulo que permita ser usada tanto por profesores que no dispongan de la misma como por estudiantes de la Facultad. Item Comparison of speleothem fabrics and microstratigraphic stacking patterns in calcite stalagmites as indicators of paleoenvironmental change(Quaternary International, 2016) Muñoz García, María Belén; Cruz, J.; Martín Chivelet, Javier; Ortega, Ana Isabel; Turrero, M.J.; López Elorza, MaialenIn the necessary task of obtaining high-resolution paleoclimate series from speleothems, the characterization of their internal microstratigraphy is a useful tool for: a) improving geochronology, and b) reaching a more complete knowledge of the speleothem formation and evolution through time and thus obtaining additional paleoenvironmental information. However, the development of standardized methodologies for microstratigraphic characterization is a pending task. In this paper, two different approaches allow construction of microstratigraphic logs for three stalagmites retrieved from two different caves. The logs correspond to vertical variations in speleothem fabrics and in microstratigraphic stacking patterns. The “fabrics logs” essentially provide information about the drip rate (sometimes used as a precipitation proxy) and the regularity or irregularity of each drip in the short-term. The “microstratigraphic stacking patterns logs” can be interpreted to obtain information about the changes in drip rates in the mid- and long-term. The results show a broad correlation between both kinds of logs that supports their validity as paleoenvironmental proxies. Fabrics formed under relatively constant and regular drips (columnar compact, open and elongated) usually constitute aggradational or progradational microstratigraphic stacking patterns. On the other hand, retractional stacking patterns are usually related with fabrics precipitated under more irregular drips (dendritic and columnar microcrystalline).However, this relation is not rigid and the information obtained from the logs is not equivalent, but complementary. The combination of both logs allows reconstruction of the hydrological history for each drip site. As all the obtained information derives directly from the drip conditions, drip effects result to be very important and can, in some cases, overwhelm the paleoclimate information recorded in each stalagmite.Item Human forager response to abrupt climate change at 8.2 ka on the Atlantic coast of Europe(Scientific reports, 2022) García Escarzaga, Asier; Gutiérrez Zugasti, Igor; Marín Arroyo, Ana B.; Fernandes, Ricardo; Núñez de la Fuente, Sara; Cuenca Solana, David; Iriarte, Eneko; Simões, Carlos; Martín Chivelet, Javier; González Morales, Manuel R.; Roberts, PatrickThe cooling and drying associated with the so-called ‘8.2 ka event’ have long been hypothesized as having sweeping implications for human societies in the Early Holocene, including some of the last Mesolithic hunter-gatherers in Atlantic Europe. Nevertheless, detailed ‘on-site’ records with which the impacts of broader climate changes on human-relevant environments can be explored have been lacking. Here, we reconstruct sea surface temperatures (SST) from δ18O values measured on subfossil topshells Phorcus lineatus exploited by the Mesolithic human groups that lived at El Mazo cave (N Spain) between 9 and 7.4 ka. Bayesian modelling of 65 radiocarbon dates, in combination with this δ18O data, provide a high-resolution seasonal record of SST, revealing that colder SST during the 8.2 ka event led to changes in the availability of different shellfish species. Intensification in the exploitation of molluscs by humans indicates demographic growth in these Atlantic coastal settings which acted as refugia during this cold event.Item Mg/Ca ratios measured by Laser Induced Breakdown Spectroscopy (LIBS): a new approach to decipher environmental conditions(Journal of Analytical Atomic Spectrometry, 2015) García Escarzaga, Asier; Moncayo Martín, Samuel; Gutiérrez Zugasti, Igor; González Morales, Manuel R.; Martín Chivelet, Javier; Cáceres, Jorge OmarThe potential application of Mg/Ca ratios in top shells of the mollusc species Phorcus lineatus (Da Costa, 1778) obtained by Laser Induced Breakdown Spectroscopy (LIBS) have been evaluated as an environmental proxy to reconstruct paleotemperatures and season of capture of molluscs for the first time. All samples were collected from Cantabrian Sea (Spain). The results were compared with instrumental sea surface temperatures (SST) and with a known reliable proxy as oxygen isotope ratio (δ18Oshell) which is mainly dependent on SST, obtained from the same shells. The measurements were taken in two different biominerals of the shell (aragonite and calcite) resulting in a correlation between Mg/Ca ratios and SST of R2= 0.43 and 0.44, respectively. Mg/Ca ratios were also studied through a long sequence on three shells collected in autumn 2012. Results show variations in Mg/Ca ratios related to seasonal changes in SST through the year and a good correlation between Mg/Ca ratios and δ18Oshell in two shells (R2= 0.70 and 0.65, respectively).Item Comparación del clima interglacial eemiense y holoceno en el norte de España a partir de los indicadores paleoclimáticos de estalagmitas de la Cueva del Cobre (Palencia)(Geotemas, 2008) Muñoz García, María Belén; Martín Chivelet, Javier; Rossi Nieto, Carlos; Ford, D.C.; Schwarez, H.P.El Eemiense se suele considerar un buen análogo del Holoceno a pesar de la diferente configuración orbital de cada época. La comparación de varios indicadores paleoclimáticos obtenidos en estalagmitas eemienses y holocenas de la Cueva del Cobre (Montaña Palentina) aporta datos que permiten verificar esta supuesta similitud. Los indicadores paleoclimáticos comparados son la tasa de crecimiento de las estalagmitas, las texturas de la calcita y los isótopos estables de oxígeno. En comparación con los holocenos, los espeleotemas eemienses son más grandes porque han crecido sin interrupción durante más tiempo, presentan una variedad menor de texturas de calcita y apenas registran láminas anuales. Además, ni las texturas de calcita ni la composición isotópica de oxígeno muestran signos de alteración diagenética. En función de estos indicadores se ha podido deducir que el clima de la zona de estudio fue durante el Eemiense ligeramente más cálido que durante el Holoceno y considerablemente más seco, contradiciendo las estimaciones más aceptadas del clima global para el Último Periodo Interglacial. El clima eemiense en la zona de estudio fue además más estable y tuvo una estacionalidad menos marcada que en los últimos 6000 años. El análisis de los cambios sincrónicos de estos indicadores ha permitido estimar una duración del Último Periodo Interglacial de ~21ka en esta zona.Item Oxfordian microbial laminites from La Manga Formation, Neuquén Basin, Argentina: Remarkable nanobacteria preservation(Journal of iberian geology, 2015) Palma Durán, Ricardo; Kietzmann, Diego A.; Comerio, M.; Martín Chivelet, Javier; López Gómez, José; Bressan, Graciela SusanaExceptionally preserved stromatolites have been found in the shallow marine carbonate facies of the Callovian-Oxfordian La Manga Formation, in the Neuquén Basin (Argentina). The stromatolites exhibit planar and crinkle lamination, often disrupted by sheet-cracks, mudcracks, and fenestral structures, which indicate periodic subaerial exposure. These and other evidences suggest that these stromatolites grew in low energy upper intertidal to lower supratidal environments. They consist of fine micrite/microsparite crystal fabrics (with a remarkable lack of allochems) that define submillimiter alternations of dense laminae. Extensive SEM examinations of polished samples of the stromatolites reveal exceptional preservation of rod-shaped bacteria, coccoid like microorganisms, and abundant aggregates of framboidal pyrite. The rod-like bacteria consists of a network of irregular distributed filaments, which range from 150 nm to an uncommon 640 nm in length; diameters range from 54 nm to 90 nm. Subspherical bodies range in size between 70 and 89 nm. The presence of abundant framboidal pyrites is interpreted as the result of the metabolic activity of sulfate–reducing bacteria and decay of organic matter.Item Chronology of Termination II and the Last Interglacial Period in North Spain based on stable isotope records of stalagmites from Cueva del Cobre (Palencia)(Journal of iberian geology, 2007) Muñoz García, María Belén; Martín Chivelet, Javier; Rossi Nieto, Carlos; Ford, D.C.; Schwarcz, H.P.New insight into the timing and structure of the Last Interglacial Period (Eemian) was obtained through U-Th dating of four speleothems from Northern Spain and an analysis of their stable isotope records. The four stalagmites examined were collected from different levels of Cueva del Cobre, a cold high-mountain cave in the Cantabrian Ranges (N Spain), in which speleothem growth took place essentially during the warmer interestadials. Through 18 TIMS and ICPMS datings and 263 stable isotope analyses, the onset of the Eemian interglacial period was precisely dated at 150±2 ka, an age consistent with a few other palaeoclimatic records but notably younger than the age ascribed by the Milankovitch theory. We also date the Eemian–Weichselian transition (~115 ka)for the first time in the Iberian Peninsula. U-Th ages revealed a consistent anomaly at ~105-100 ka BP, which could be related to a drastic environmental change during the MIS-5c interestadial. This event would have caused the resetting of the U-Th system at the base of the stalagmites during a short time interval. In addition, we propose a new simple geochemical test to ensure the lack of disturbance of this type of samples for dating purposes.Item Ciclos carbonatados submareales-perimareales de alta frecuencia del Aptiense inferior (Fm. San Esteban, cuenca Vasco-Cantábrica): registro de cambio climático(Geotemas, 2016) Rosales, Idoia; Najarro, María; López-Cilla, I.; Martín Chivelet, JavierEl análisis detallado de facies de las calizas de la Formación San Esteban del Aptiense inferior de Cantabria ha permitido caracterizar 15 tipos de litofacies depositadas en ambientes submareales a supramareales. Las facies se organizan en ciclos somerizantes que culminan con superficies de exposición subaérea, evidenciado variaciones relativas del nivel del mar de alta frecuencia/baja amplitud. Se distinguen dos tipos de ciclos en función de las facies y naturaleza de las superficies que los culminan. Los ciclos Tipo-1 están dominados por facies submareales. La secuencia ideal comienza con rudstone bioclástico-intraclástico, seguido de wackestone de Chondrodonta, floatstone de rudistas, boundstone de rudistas y mudstone de milólidos. El techo es una superficie neta con bioturbación y marcas de raíces estilo pseudomicrokarst. Los ciclos Tipo-2 comienzan con floatstone oncolítico-litoclástico, seguido de floatstone de rudistas, packstone-grainstone de foraminíferos, boundstone de rudistas y finalmente rudstone oncolítico, mudstone fenestral y/o estromatolitos laminares a hemiesféricos. Culmina con rasgos subaéreos de desecación y conglomerados calcáreos de cantos negros con microestructura alveolar y rizolitos calcificados. Los ciclos Tipo-1 caracterizaron condiciones ambientales húmedas, mientras que los de Tipo-2 caracterizaron condiciones semi-áridas. La evolución vertical de los ciclos refleja una transición climática de tipo greenhouse a otra coolhouse tras el OAE-1a.Item Event stratigraphy of the upper Cretaceous to lower Eocene hemipelagic sequences of the Prebetic Zone (SE Spain): Record of the onset of tectonic convergence in a passive continental margin(Sedimentary Geology, 2007) Martín Chivelet, Javier; Chacón Pichaco, BeatrizIn the Eastern Prebetic Zone of SE Spain, upper Cretaceous to lower Eocene hemipelagic sequences deposited in the ancient southern passive continental margin of Iberia are well exposed. The long-term stratigraphy of these sequences is punctuated by six regional tectonic events, which induced rapid changes in palaeogeography and regional tectonics. Each event configured a new genetic scenario for sedimentation, which lasted until the next tectonic reorganization and, in turn, controlled the deposition of an event bounded stratigraphic unit (EBSU). The ages of these events, determined chronobiostratigraphically, are: intra-Coniacian, late Santonian, “mid” Maastrichtian, latest Maastrichtian–earliest Danian, late Thanetian and intra-Ypresian. All the events, but the first, are interpreted here as the result of contractional tectonic pulses, related to changes in intraplate stresses during the onset of African–European convergence. Through correlations with both adjacent shallow marine carbonates (Prebetic platform) and basin pelagites (Subbetic), along with other basins of Iberia and North Africa, the long-term evolution of the continental margin is integrated within the geodynamic framework of the western Tethys.Item Chapter 10 Traction Structures in Contourites(Contourites, 2008) Martín Chivelet, Javier; Fregenal Martínez, María Antonia; Chacón, B.; Rebesco, M.; Camerlenghi, A.Publisher Summary This chapter reviews the traction structures in contourites that are formed in deep marine systems under the influence of oceanic bottom currents. Some general and theoretical constraints on the range of likely processes forming primary sedimentary structures in contourites are established. Each sedimentary structure is documented and analyzed under the constraints and the main controversial points are discussed. Traction structures are inherent to sediments generated or influenced by water flows. Contouritic deposits are developed in close association with bottom currents and show a noticeable variety of bedforms and structures; their study is essential for understanding the patterns of oceanic palaeocirculation. The controversy of traction-structures is also discussed. The proposed sediment structures are, (1) current ripples and cross-lamination, (2) lenticular and flaser bedding, (3) horizontal, subhorizontal, and sinusoidal lamination, (4) large -scale cross-bedding, (5) erosional structures, and (6) grading. The wide spectrum of sedimentary structures in contourites reflects the numerous factors that control their formation including current intensity, steadiness of flow, supply of sediment, hydrochemistry, texture, and composition of available sediment. The Faro Drift facies model and the Gulf of Mexico facies model emphasize the role of primary sedimentary structures.